Med/surg Exam Ii

Front 1

Causes of Pulmonary Parenchymal Disease

Back 1

-Pneumonia
-Pulmonary edema: cardiogenic and non-cardiogenic
-Hemorrhage
-Pulmonary thromboembolism
-Neoplasia
-Pulmonary inflammatory disease
-Acute Respiratory Distress Syndrome (ARDS)

Front 2

Clinical signs of Pulmonary Parenchymal Disease

Back 2

-Increased respiratory rate and effort
-Restrictive respiratory pattern
-Harsh Broncho-vesicular sounds or crackles
-Nasal discharge
-Productive cough
-Hypoxemia signs

Front 3

Diagnosis of Pulmonary Parenchymal Disease

Back 3

-PE and Hx
--especially history of travel
-CBC/chem screen
--look for inflammatory response
-Thoracic radiographs
-CT scan
-Tracheal wash to identify bacteria or neoplasia
-Bronchoscopy
-Lung aspirate
-Lung biopsy

Front 4

Normal defense mechanisms in the Respiratory System

Back 4

-Nasopharynx
-Mucociliary escalator
-Cough reflex
-Brounchus-associated lymphoid tissue (BALT)
-IgA
-Alveolar macrophages
-Pulmonary lymphatics and lymph nodes

Front 5

Causes of Pneumonia

Back 5

-Aspiration (most common)
--subdivision of bacterial pneumonia
-Bacterial
-Viral
--can lead to secondary bacterial infection
-Protozoal
-Fungal
-Pneumonia is more common in dogs than in cats

Front 6

Causes of Bacterial Pneumonia

Back 6

-Immunosuppression
--cushing's disease, increased cortisol levels
-Anatomical abnormalities
--cleft palate
-Chronic airway disease
--asthma
-Aspiration
-Viral, fungal, or parasitic disease
-Trauma or hemorrhage
-Inhalation of irritant gasses

Front 7

Aspiration Pneumonia

Back 7

-Inhalation of foreign material
--most often GI contents, oral secretions, foreign material
-Underlying conditions can predispose patient
--pharyngeal/laryngeal dysfunction
--megaesophagus
--cleft palate
--abnormal mentation
--recumbency, debilitation
--sedation or anesthesia
-Recovering from surgery greatly increases predisposition

Front 8

Phases of Aspiration Pneumonia

Back 8

1. low pH of GI contents cause injury and bronchoconstriction
2. Inflammation occurs and results in edema
3. Bacteria in aspirated material causes secondary bacterial pneumonia
-Clinical signs, diagnosis, and treatment are the same as for other bacterial pneumonias

Front 9

Bacterial Pneumonia Clinical Signs

Back 9

-Signs range in severity from intermittent coughing and mild exercise intolerance to dyspnea, cyanosis, and septic shock
-"Walking pneumonia"
-Can also have nasal discharge, productive cough, fever, and leukocytosis

Front 10

bacterial Pneumonia route of infection

Back 10

1. Inhalation is most common
--Will see cranioventral alveolar pattern and air bronchograms on radiographs
--Due to primary pathogens or aspiration of foreign material
2. Hematogenous spread
--uncommon in cats and dogs
--occurs with bacteremia, bacteria can end up anywhere
--will see nodular infiltrates on radiographs

Front 11

Primary pathogens in Bacterial Pneumonia in Dogs

Back 11

-Bordetella bronchiseptica
-Streptococcus zooepidemicus
-Mycobacterium

Front 12

Opportunistic pathogens in Bacterial Pneumonia in Dogs

Back 12

-E. coli
-Pseudomonas
-Klebsiella
-Enterobacter
-Pasteurella
-Streotococcus
-Staphylococcus
-Mycoplasma
-Acinetobacter

Front 13

Bordetella bronchiseptica

Back 13

-Gram- rod bacteria
-Transmitted by aerosolization
-Attaches to columnar epithelial cells in respiratory tract
--causes ciliary stasis, paralyzes muco-ciliary elevator
--Allows organism to persist in the airway for prolonged periods of time
-Adult dogs will show upper airway signs
-Puppies can present with bronchopneumonia
-Often present in pet stores

Front 14

Primary pathogens in Bacterial Pneumonia in Cats

Back 14

-Bordetella bronchiseptica
-Streptococcus sooepidemicus
-Mycobacterium
-Mycoplasma

Mix of gram+ and gram-

Front 15

Opportunist bacteria in Bacterial Pneumonia in Cats

Back 15

-Pasteurella
-Pseudomonas
-Staphylococcus
-Streptococcus
-E.coli
-Nocardia
-Actinomyces
-Bacteroides

Front 16

Mycoplasma

Back 16

-Smallest free-living microorganisms
-Lack cell walls
-Need special culture media to grow
-Can be normal flora in the lungs of dogs
--NOT normal flora in lungs of cats
-Sensitive to fluroquinolones, macrolides, tetracyclines, and chloramphenicol

Front 17

Diagnosis of Bacterial Pneumonia

Back 17

-Thoracic radiographs are main diagnostic tool
--air bronchograms
--lobar sign
-Evaluate patient to find any underlying cause
-CBC/Chemistry screen/Urinalysis
-Take samples for cytology, culture and sensitivity
--trans-tracheal wash
--endotracheal wash
--broncho-alveolar lavage
-Obtain test results before starting antibiotic therapy

Front 18

Trans-tracheal wash

Back 18

-Use to diagnose pneumonia
-Don't want animal too sedate, they have to cough to get stuff
-Put needle into trachea between cartilage rings

Front 19

Endo-tracheal wash

Back 19

-Can do in anesthetized animals
--big aggressive dogs
--squirrely cats
--any animal that is going to be anesthetized anyway for a procedure

Front 20

Treatment of Bacterial Pneumonia

Back 20

-Broad-spectrum antibiotics, start as early as possible
--give IV if patient is critical
-Supplemental O2
-IV fluid therapy
--very important! keep patient well-hydrated without over-hydrating!

Front 21

Oral antibiotic therapy for Bacterial Pneumonia

Back 21

-Clavamox (broad spectrum)
-Azythromycin (bordatella)
-Enrofloxacin (good penetration into lungs)

Front 22

IV antibiotic therapy for bacterial Pneumonia

Back 22

-Ampicillin/Enrofloxacin
-Clindamycin/Enrofloxacin
-Ampicillin/Amikacin
-Timentin
-Clindamycin/2nd or 3rd generation cephalosporin

Front 23

Treatment for Bacterial Pneumonia

Back 23

-Nebulization and coupage
--fine mist to get meds as deep as possible
-Bronchodilators can be used for acute aspiration
--you SAW it happen
--not great for long-term
-Mucolytics to break up mucus

Front 24

Monitoring Patient with Pneumonia

Back 24

-Pneumonia causes Hypoxemia
--V/Q mismatch, intrapulmonary shunt
-Pulse Oximetry, should be more than 94%
-Arterial blood gasses, should be more than 80mmHg
-PaO2:FiO2 ratio
--normal is over 400
-Repeat thoracic radiographs

Front 25

Viral Pneumonia
Distemper

Back 25

-Viral pneumonia in Dogs
-Infects epithelial cells throughout the body
-1st sign is conjunctivitis with a dry cough
-Progresses to productive cough and GI signs
-Predisposes animal to secondary bacterial infection
--disruption and inflammation of immune system

Front 26

Distemper on Thoracic Radiographs

Back 26

-Diffuse interstitial pattern
-Progresses to alveolar pattern with secondary bacterial pneumonia

Front 27

Diagnostic testing of Distemper

Back 27

-Thoracic radiographs
--diffuse interstitial pattern that progresses to alveolar pattern
-CBC: leukopenia
-Fluorescent antibody testing on conjunctival epithelial cells

Front 28

Distemper treatment

Back 28

-Supportive care
-Treat for secondary bacterial pneumonia

Front 29

Canine Influenza

Back 29

-Viral pneumonia in dogs
-Highly contagious respiratory disease (new in 2004)
-Similar to equine influenza virus, mutated to dogs
-Mild clinical form: soft or dry cough
--may have nasal discharge
-Severe clinical form: High fever, clinical signs of pneumonia
--affects 5-8%
--5% mortality rate
Dx: serology, acute and convalescent titers
-Tx: Supportive care, antibiotics for secondary bacterial infection
-Prevention: vaccinate!

Front 30

Dogs with increased risk to Canine Influenza

Back 30

-Show dogs
-Dogs at a boarding facility
-Shelter dogs
-Racing dogs

Front 31

Protozoal Pneumonia

Back 31

-Toxoplasma Gondii is main concern
-Worldwide distribution, exists everywhere!
-Common in cats, look for FeLV/FIV immunosuppression
-Rare in dogs
-Radiographs will show fluffy interstitial to nodular alveolar pattern
-Dx: tachyzoites in tracheal wash or bronchio-alveolar fluids
--can also do serology
-Tx: clindamycin or sulfa drugs

Front 32

Fungal Pneumonia

Back 32

-Secondary to histoplasmosis, blastomycosis, and coccidiomycosis
-History of slowly progressive respiratory signs
--weight loss
--lymphadenopathy
--fever
-Geographical location and travel history are important for diagnosis

Front 33

Geographical Distribution of Fungal Pneumonia

Back 33

1. Histoplasmosis:
--Mississippi
--Missouri
--Ohio river valley
2. Blastomycosis:
--Mississippi, Missouri, Ohio river valleys
--Mid-atlantic states along waterways
3. Coccidiomycosis:
--SW us and Mexico

Front 34

Diagnosis of Fungal Pneumonia

Back 34

-Thoracic Radiographs
--diffuse interstitial pattern to nodular pattern
--hilar lymphadenopathy
-Tracheal wash, broncho-alveolar lavage, lung aspirates
--identify organism
-Lung biopsy
-Fungal Cultures
-Serology
-Can look like metastatic neoplasia

Front 35

Treatment of Fungal Pneumonia

Back 35

-Do not treat unless you see the organism!!
-Antifungals
--Itraconazole, Fluconizole, Amphotericin B
--watch out for toxic side effects
-Long treatment, 4-6 months or longer
-Patient may get worse initially due to inflammation from death of organisms

Front 36

Pneumocystis carnii

Back 36

-Causes pulmonary disease in immuno-compromised patients
-Rare in dogs, esp. young dogs
-Not reported in cats
-Chronic signs
--weight loss, exercise intolerance, respiratory distress, non-productive cough
-Initially classified as a protozoal

Front 37

Pneumocystis carnii Diagnosis and Treatment

Back 37

-Radiographs: mixed alveolar or diffuse interstitial pattern
--cor pulmonale (right sided heart enlargement)
-Dx: organisms in tracheal wash or lung aspirates
-Tx: trimethoprim sulfa or pentamidine
-Poor prognosis, but some reports of success

Front 38

Key points of Pneumonia

Back 38

-Common cause of respiratory disease in the dog and cat
-Bacterial pneumonia is the most common
--aspiration
--infectious
--hematogenous
-Diagnostics should include physical exam, history, thoracic radiographs, and tracheal wash
-Other less common infectious causes of pulmonary parenchymal disease:
--viral
--fungal
--protozoal

Front 39

Anatomy of the Pleura

Back 39

-Pleura is a single layer of cells
-Visceral pleura covers the lungs
-parietal Pleura lines the thoracic cavity
-Mediastinum is anatomically pleura but not functionally
-Pleural fluid is formed by starling forces

Front 40

Pleural Space

Back 40

-Potential space between visceral and parietal pleura
-Filled with a small amount of fluid

Front 41

Act of Breathing

Back 41

-Increases volume due to contraction of the diaphragm
-Increase in volume causes decrease in pressure
-Anything in the pleural space that takes up space and volume allows for less of a decrease in pressure
--less inflation of the lung

Front 42

Pathophysiology of the Pleura

Back 42

-Air or fluid in the pleural space causes parietal and visceral pleura to separate
-Lungs collapse due to changes in pressure
-Chest wall expands

Front 43

Hypoventilation

Back 43

-Not enough CO2 is blown off
-Results in ventilation/perfusion mismatch
-CO2 is most soluble, will be affected the least by disease
-O2 is much less soluble, is affected easily by disease

Front 44

Clinical Findings of Lung Issues

Back 44

-Great variability
-Insidious onset or acute decompensation with chronic disease
-Rapid shallow breathing due to decreased tidal volume, decreased functional reserve capacity, or decreased compliance

Front 45

Signs of Lung issues

Back 45

-Elbows abducted
-Head extended
-Working hard to breathe
-Animal is sternal or sitting
-Cough
-Muffled heart sounds
-Breath sounds are absent ventrally with effusions

Front 46

Reasons an animal might have to work hard to breathe

Back 46

-Upper airway obstruction
-Issue in pleural space
-Diaphragm
-Issue with lungs

Front 47

Reasons for Muffled Heart sounds

Back 47

-Fluid
-Air
-intestines
-Just fat

Front 48

Diagnosis of Lung issues

Back 48

-Thoracic radiographs (orthogonal views)
-Thoracocentesis
-Pleural fluid analysis

Front 49

Chest tap Rules

Back 49

1. Tap where the heart is not
2. Do not tap the liver or into the abdomen
--tap cranial to the 8th or 9th rib
3. Tap on the cranial side of the rib
--avoid intercostal vessels that run on caudal side of the rib
4. Tap until you get negative pressure
--do not pull too hard! Will dislodge clots

Chest tap normally makes the animal feel much better
-some free air remaining in the pleural space is OK if animal looks fine otherwise

Front 50

Chest Tube

Back 50

-Use with repeated or continuous aspiration of chest cavity
--more than 3 chest taps, time for a chest tube
-Ideally place with anesthesia and control of airway
--intubate!
-Tunnel technique, open technique, or trochar technique

Front 51

Open technique for Chest Tube placement

Back 51

-Have to close 2 incisions
-Have controlled placement of the tube
-Pull skin forward, make incision
--releasing skin moves cutaneous incision away from location of pleural incision

Front 52

Chest tube/3-way stopcock interface

Back 52

-Not a very good system
-Increased potential for leakage with more components
-Need to make sure connections are secure
-Test by clamping chest tube and trying to pull off air
--if you can get air with tube clamped, there is a leak somewhere

Front 53

3 bottle technique for chest tap

Back 53

-Pre-determines suction on the system
-Prevents air from going back into the chest

Front 54

Pneumothorax on Radiograph

Back 54

-heart will be elevated
--decreased cardiosternal contact
-Will see free air in the pleural space

Front 55

Causes of Pneumothorax

Back 55

-Penetrating wounds
-Pulmonary trauma
--Most often blunt trauma
-Esophageal rupture
-Rupture of pulmonary blebs or bullae
--can cause spontaneous pneumothorax

Front 56

Hypoxic Pulmonary Vasoconstriction

Back 56

-Decreased oxygen in alveolus results in Ventilation Perfusion mismatch
-Alveolus collapses, blood is shunted through tissue
-Arteries constrict, constriction slows blood flow
--attempts to rectify mismatch
-Arteries redirect blood to alveoli with air

Front 57

Tension Pneumothorax

Back 57

-Leak in the lung
-Each time animal breathes in air gets into pleural space and does not come out
-Blood is pulled out of the chest due to change in pressure
-DO NOT VENTILATE this animal!
--Intubate and tap at the same time

Front 58

Signs of Tension Pneumothorax

Back 58

-Difficulty breathing
-Circulatory collapse
-If using chest tap, will be pulling off way too much air with 3-way stopcock
-On radiographs will see pleura pulling away from chest wall

Front 59

Spontaneous Pneumothorax

Back 59

-Caused by blebs/bullae
-hard to image

Front 60

Pleural Effusion treatment

Back 60

-Treat underlying cause
-Get sample

Front 61

Pleural Effusion Diagnosis

Back 61

-Analysis of pleural fluid (get a sample!!)
-Evaluation of cardiac function
--ascultation, radiographs, echocardiography
-Bloodwork
-Investigation of lungs, mediastinum, and diaphragm
-Investigation of other diseases
--pancreatitis
--protein losing nephropathy, enteropathy

Front 62

Pleural Fluid Analysis

Back 62

-Total cell count
-Total protein and specific gravity
-Aerobic and anaerobic culture
-Direct smears stained for cytology
-With chylothorax, get triglyceride and cholesterol levels

Front 63

Pleural Effusion Treatment

Back 63

-Drain all fluids
--unless hemorrhagic and coagulopathy is suspected (rodenticide)
-Do not drain all fluids if need ultrasonographic window
--cannot ultrasound through gas, can through fluid

Front 64

Trasudates

Back 64

-Fluid with low protein count, low cell count
-Less than 1500 cells per uL
-Low total protein, less than 3g/dL
-Usually the result of hypoalbuminemia
-Decreased production of proteins in liver or increased loss of proteins in kidney and GI

Front 65

Modified Transudates

Back 65

-1500-5000 cells per uL
-Total protein is 3g/dL
-Almost any disease causing long-standing effusion will have modified transudates
--chronic effusion leads to modified transudates

Front 66

Differential Diagnoses for Modified Transudates

Back 66

-Myocardial failure
-Pericardial effusions
-Neoplasia
-Diaphragmatic hernia
-Lung lobe torsion
-Pancreatitis

Front 67

Exudates

Back 67

-More than 5,000 cells per uL
-More than 3g/dL of protein
-High nuclear cell counts
-Non-septic causes:
--FIP, chylothorax, neoplasia, fungal infection, foreign body
-Septic causes:
--Wound, esophageal perforation, necrotic tumor, pulmonary abscess

Front 68

Chylothorax

Back 68

-Accumulation of Chyle in pleural space
-Milky white fluid
-Trauma was originally suspected as cause, but unlikely
--thoracic duct repairs itself quickly
-Dilation and leakage from thoracic duct
--Lymphangectasia
--Leak in duct AND increased pressure

Front 69

Lymphangectasia

Back 69

-Physical obstruction of lymph flow into cranial vena cava
-Causes:
--neoplasia
--heartworm
--thormbosis
--lung lobe torsion
-Increased cranial vena caval pressure due to heart failure, pericardial disease, or throboembolism
-Very often idiopathic

Front 70

Chylothorax Fluid

Back 70

-Pleural fluid to serum triglyceride ratio should be more than 1
--pleural fluid should be higher
-Pleural fluid triglyceride levels should be more than 100mg/dL
-Compare triglyceride in serum to pleural fluid
-Interpret with caution in animals that have not eaten for several days

Front 71

Chylothorax Treatment

Back 71

1. Medical:
--drain pleura
--put animal on low-fat diet (does not reduce volume of chyle)
2. Surgical:
--thoracic duct ligation as close to the diaphragm as possible
--pericardectomy

Front 72

Pyothorax

Back 72

-Usually occur secondary to something else
-Penetrating wounds
-Esophageal perforations
-Migrating foreign bodies
-Extension from Pneumonia
-Pulmonary abscessation
-Neoplasia
-Hematogenous Spread

Front 73

Pyothorax in Cats

Back 73

-Anaerobes:
--peptostreptococcus
--Bacteroides
--fusobacterium
--prevotella
-Aerobes
--pasturella
--actinomyces

Front 74

Pyothorax in Dogs

Back 74

-Anaerobes:
--peptostreptococcus
--bacteroides
--Fusobacterium
--porphyromonas
-Aerobes:
--actinomyces
--pasturella
--E. coli
--Streptococcus

Front 75

Treatment for Pyothorax

Back 75

-Chest tube drainage
-IV fluids
-Colloids
-Appropriate antimicrobial therapy

Front 76

Pyothorax Indications for Surgery

Back 76

-Failure to respond to medical therapy
--inability to aspirate effusion through properly placed and functional thoracostomy tubes
--Failure of effusion to resolve over reasonable period of time, usually a week
-Obvious surgical lesion found
--abscessed lung lobe
--foreign body

Front 77

Pulmonary Contusions

Back 77

-Interstitial and Alveolar hemorrhage following blunt thoracic trauma
-May have other concurrent thoracic injuries also
--rib fractures
--pneumothorax
--pleural effusion

Front 78

Clinical Signs of Pulmonary Contusions

Back 78

-Acute or delayed onset, may not see signs right away
-Can worsen over several hours
-Dyspnea
-Increased breath sounds or crackles
-Shock
-Concurrent injuries
-Hemoptysis (coughing up blood) is uncommon

Front 79

Treatment for Pulmonary Contusions

Back 79

-Mostly supportive care
-Oxygen
-Careful IV fluids
--do not want to blow off clots
-Analgesia
-May or may not intubate for positive pressure ventilation
-Be aware of coagulopathies

Front 80

Allergic Airway Disease

Back 80

-Broad spectrum of diseases
-Parasitic
-Allergic Bronchitis
-Feline Asthma
--be sure to ask about hairballs, hairballs look like asthma to owners
-Pulmonary infiltrates with eosinophils

Front 81

Pathology of Allergic Airway Disease

Back 81

-Bronchial and alveolar inflammation
--Edema
--mucous secretion
--smooth muscle hypertrophy
--bronchi and bronchiolar constriction
-Eosinophils often predominate
-Dyspnea due to closure of bronchioles

Front 82

Clinical Signs of Allergic Airway Disease

Back 82

-Can be acute or chronic
-Rapid, shallow breathing
-Expiratory dyspnea, difficulty exhaling
-Cough
-Loud breath sounds on ascultation
--crackles and wheezes can also be heard
--wheezes typically on expiration
-Radiographs will show bronchiolar or interstitial pattern

Front 83

DDx for Allergic Airway Disease

Back 83

-Hypersensitivity reaction
--Lung parasites
--heartworm
--drugs
--inhaled allergens
--bacterial, fungal, or neoplastic issues

Front 84

Bronchus with Allergic Airway Disease

Back 84

-Will be hyerpemic
-Narrow lumen
-Mucus present in lumen

Front 85

Diagnostics for Allergic Airway Disease

Back 85

-CBC/Chem/Urinalysis
-Radiographs
-Endotracheal wash or BAL
-Possible tests:
--lung aspirate or biopsy
--heartworm testing
--fecal float
--fungal testing depending on geography

Front 86

Treatment for Allergic Airway Disease

Back 86

-Treat any underlying infections
-Discontinue any medications
-Minimize exposure to allergens
-Glucocorticoids to treat inflammation
-Bronchodilators to treat bronchoconstriction
-Consider inhaled medications

Front 87

Pulmonary Edema

Back 87

-Fluid in the interstitium or alveoli
--fluid in the airspace itself
-Cardiogenic: high-pressure edema
--congestive heart failure
-Non-cardiogenic: leaky-vessel edema
--neurogenic edema
--acute lung injury or ARDS

Front 88

Neurogenic Edema in Lungs

Back 88

-Non-cardiogenic
-"Leaky-vessel" edema
-Most often seen after an event
--upper airway obstruction, choking
--seizure, head trauma, electrocution
--non-fatal drowning
-Unknown pathogenesis
--vasoconstriction in periphery and blood goes to the brain?
-Clinical signs vary with severity
-Alveolar pattern in caudodorsal lung fields on radiographs
-Good prognosis with Supportive care

Front 89

Neurogenic Edema on radiographs

Back 89

-Alveolar pattern in caudo-dorsal lung fields

Front 90

ALI/ARDS causes

Back 90

-Continuum of pulmonary injury, inflammation, and vasculitis
-Often the result of systemic inflammation that originates outside of the lung
--SIRS
--Sepsis
--Heat stroke
--Trauma
--Pancreatitis

Front 91

ALI/ARDS

Back 91

-High protein fluid and inflammatory infiltrate in air spaces
-Acute to sub-acute onset of tachypnea and dyspnea
-Moderate to severe hypoxemia
-Coughing, crackles or wheezes audible on auscultation

Front 92

ARDS lung

Back 92

-Inflamed tissue
-Oozes on cut surface
-Lots of fluid in the lung
-Can develop quickly
-No longer light pink, clean structure
-Closed airways with lots of inflammatory cels and proteinaceous fluid

Front 93

ARDS on radiograph

Back 93

-Alveolar pattern without evidence of congestive heart failure
-Will see air bronchograms
-Alveolar infiltrates

Front 94

Treatment for ALI/ARDS

Back 94

-Supportive care
-Treat underlying diseases
--there is always a trigger, need to find underlying cause
-Give cautious fluid therapy
--can flood the lungs if too much is given
-Intubate for positive-pressure ventilation

Front 95

Pulmonary Thromboemobilsm

Back 95

-Acute or Chronic pulmonary vascular occlusion
-Emboli can be secondary to fat or clotting
-Interferes with normal pulmonary blood flow and gas exchange
--alveoli get fresh O2 but no blood flow
--pulmonary dead space

Front 96

Predisposing Causes for Pulmonary Thromboembolism

Back 96

-SIRS/Sepsis
-Pancreatitis
-Protein-losing enteropathy or nephropathy
-IMHA
-Endocrine Disease
-Steroid therapy
-Many other diseases can predispose
-Catheter can be nidus for clot formation

Front 97

Clinical Signs of Pulmonary Thromboembolsim

Back 97

-Labored breathing
-Tachypnea
-Lethargy
-Altered mentation
-Collapse
-Signs are related to comorbidities
-Many are clinically silent
--incidental finding

Front 98

Diagnostic workup for Pulmonary Thromboembolism

Back 98

-Chemistry/CBC/Urinalysis
-Arterial Blood gas
-Endocrine testing
-Coagulation testing +/- thromboelastography
--D-Dimers indicate breakdown product of a clot
-Radiographs or advanced imaging

Front 99

Pulmonary Thromboembolism Treatment

Back 99

-Supportive Care
-Anticoagulation therapy short-term or long-term
-Thrombolytic therapy?
--Meds that break down clot that is already present
-Treat underlying diseases! Underlying hypercoagulability

Front 100

Pulmonary Fibrosis

Back 100

-Pathologic inflammation of the lung with scarring
--excessive remodeling of tissue
-Unknown cause, likely mediated by inflammatory cytokines (IL, TNF-a)

Front 101

Possible Predisposing Causes for Pulmonary Fibrosis

Back 101

-Primary pulmonary disease with deranged remodeling
-Connective tissue disorder, disorder of formation
-Environmental pollutants
-Drug reactions
--systemic drugs affecting the lungs
-Neoplasia
-Idiopathic in west-highland terriers

Front 102

Clinical Signs of Pulmonary Fibrosis

Back 102

-Often slow or subtle in onset
--chronic disease
-Exercise intolerance
-Cough
-Dyspnea
-Collapse
-Increased blood pressure in pulmonary circuit
--pulmonary hypertension

Front 103

Pulmonary Fibrosis on Radiograph

Back 103

-Diffuse multi-lobar interstitial pattern
-Pulmonary hypertension
-Right ventricular hypertrophy

Front 104

Fibrotic Lungs with Pulmonary Fibrosis

Back 104

-Abnormal, gross-looking lungs

Front 105

Pulmonary Fibrosis Diagnostic Testing

Back 105

-Radiographs with or without CT scan
-Arterial blood gas
-Endotracheal wash or BAL
--need to rule out pneumonia or neoplastic cause
-Lung biopsy

Front 106

Pulmonary Fibrosis Treatment

Back 106

-Supportive Care
-Glucocorticoids
-Bronchodilators
-Guarded prognosis, depends on how severe the patient is
-Slow onset and gradual progression

Front 107

3 Components of Bovine Respiratory Disease

Back 107

1. Management
--environment, feeding, herd density
2. Viral Disease
--viral diseases can lead to bacterial infections
--suppress immune system and allow bacteria to invade
3. Bacterial disease

Front 108

Respiratory Disease in Young Calves

Back 108

-HUGE problem in young animals
-A calf getting sick dramatically reduces productive life of the calf
-Keeping animals individualized when young prevents spread of disease
--stress allows for vulnerability

Front 109

Young Stock Respiratory Disease in Beef

Back 109

-Disease generally comes during weaning
-Calves are a little older than in dairy
-Disease caused by stressful movements and changes

Front 110

Adult Bovine Respiratory Disease

Back 110

-Sporadic issue, not common
-Animal density and confinement will increase the respiratory disease process

Front 111

Ventilation and Bovine Respiratory Issues

Back 111

-Animal density is critical for ventialtion
-Need a minimum of 4 air changes every hour to ensure clean, safe air
--needs to occur year-round

Front 112

Functions of Ventilation of a Barn

Back 112

1. Remove CO2 and ammonia
--damages upper respiratory tract
2. Remove heat and moisture
--decreases amount of airborne bacteria
--Large animals produce a lot of heat, need to get rid of it

Front 113

Natural Ventilation Systems in Barns

Back 113

-Open roof systems
-Allows hot air to rise and exit
-Old bars are not designed for optimal air flow
-Natural air flow is not very consistent or reliable
-best when combined with big mechanical fans or +pressure tubes

Front 114

Mechanical Ventilation Systems in barns

Back 114

-Fans in closed barn
-Air has to go in AND out
-Positive pressure tubes
--holes placed at regular intervals provide airflow
--gives consistent airflow throughout the entire barn
--easy to adapt to older barns
-Do not want to create drafts!

Front 115

Pulmonary Defense Mechanisms

Back 115

1. Mucociliary defense system
2. Pulmonary Alveolar macrophages
3. Secretory System

Front 116

Mucociliary Defense System

Back 116

-Warms and filters incoming air
-Cilia remove dust and organisms
--give escalator effect, brings mucus back up and out
-Very efficient, most efficient method for defending against pathogens
-Mucus captures and traps pathogens going from upper respiratory tract to lower respiratory tract
--prevents bacteria from getting into lower respiratory tract
-90% effective

Front 117

Factors Affecting Mucociliary Defense System

Back 117

-Dehydration decreases mucus production
-Starvation
-Toxic gasses, Ammonia
--death of mucociliary cells and ciliostasis
-Viral infections
-Stress
-Rectify by keeping animals warm and dry, well fed, and decrease stress

Front 118

Pulmonary Alveolar Macrophages

Back 118

-Lower Respiratory Tract
-Macropahges
-NOT neutrophils
-Less efficient system, 50% efficiency
--takes a few days to respond and remove particles
-Neutrophils only enter lung to respond to infection
--infection has to be present

Front 119

Secretory System

Back 119

-Cell-mediated immunity
-Local immunity
--most important, IgA and Interferon, natural antiviral properties
-Serum antibody is less important
-Secretory and local antibodies are both produced and important

Front 120

Anatomy of the Bovine Lung

Back 120

-Unique lung system
-Right accessory lung lobe
-Right lung has more lung tissue than left lung, more capacity
--55-60% of total capacity
-Right cranial bronchus comes off before tracheal bifurcation
--Enters right cranial lung lobe
--first opportunity for pathogens to get into the lungs
--will see disease in right cranial lung lobe 1st
-Infections are easily walled off to prevent collateral exchange

Front 121

Basal Lung Metabolism

Back 121

-Uses 45% of bovine lung capacity
--cows use more of lung capacity for lung metabolism
-Horses and humans use 20% of basal metabolism

Front 122

Lung sounds in the Bovine

Back 122

-Duller on left side due to rumen
-Vesicular sounds can be heard throughout the entire lung field
-Bronchovesicular sounds are heard best in bronchi

Front 123

Signs of Bovine Respiratory Disease

Back 123

-Animal looks sick
-Dehydrates easily, dry nose
-Do not cough regularly, cough is not very efficient
-Sunken eyes
-Droopy ears

Front 124

Bovine Viral Respiratory Diseases

Back 124

-Infectious Bovine Rhinotracheitis
-Parainfluenza Type 3
-Bovine Respiratory Syncytial Virus
-Bovine Viral Diarrhea Virus

-Animal does not usually just have a virus, usually has virus AND bacterial infection

Front 125

Infectious Bovine Rhinotracheitis
IBR

Back 125

-Affects mucosa of nasal and upper respiratory passages
-herpes type I virus
--latency period, goes dormant after initial infection
-More than 80% of cattle are seropositive
-Latent infections are common

Front 126

IBR Syndromes/forms of Disease/Sequelae

Back 126

-Respiratory
-Conjunctival
--not always corneal, no corneal lesions
-Infectious Pustular vulvovaginitis
-Abortion
-Low conception rates
-Follicular Disease

Front 127

Infectious Pustular Vulvovaginitis

Back 127

-Ulcerated lesions on vulva and vagina
-Syndrome of Infectious Bovine Rhinotracheitis (IBR)

Front 128

IBR clinical Signs

Back 128

-High fever, over 105F
-Mild dyspnea
--not huffing and puffing, but not normal either
-White nasal plaques (Pathognomonic for herpes viral infections)
-WBC profile is normal
-Mild/rapid recovery without secondary bacterial infection
--should recover in a few days

Front 129

Herpes Infections in cattle

Back 129

-Serous nasal discharge
-Bacterial infection causes cloudy, dense nasal secretions
-White plaques with red and inflamed nasal tissue
--"red nose" disease
-Lungs should sound normal
--upper respiratory infection
-Trachea should sound abnormal

Front 130

IBR Rare Presentations

Back 130

-Encephalitis
--with meningitis
--non-purulent
-Fatal septicemia
--in calves less than 1 week old
--necrosis in GI tract with peritonitis
-Balanopostitis: localized infection of white plaques
--plaques on penis and prepuce

Front 131

IBR Diagnosis

Back 131

-Serology
--not best method, 80% of animals are seropositive
--virus neutralization
-Can compare acute and convalescent paired titers
--4x increase from acute to convalescent indicates infection
-Virus isolation
-Fluorescent Antibody
-PCR

Front 132

IBR Treatment

Back 132

-Palliative treatment
-Analgesic.antipyretic
-Banamine (Flunixin meglumine)

Front 133

IBR Prevention

Back 133

-Vaccination!
-Do not rely on natural exposure for treatment
-ALL Cattle should be vaccinated against herpesvirus 1
-Can give as modified live intranasally or as killed virus

Front 134

IBR Intranasal Vaccine

Back 134

-Best production of interferons
-Rapid onset of immunity
--will have local antibodies in 48 hours
--secretory antibodies in 1 week
-Does not cause abortions
-Difficult to give, have to put it up the nose
-Very useful in outbreaks

Front 135

IBR Modified Live Virus vaccine

Back 135

-Injectable vaccine
-Abortogenic, can cause abortions
--can be avoided with routine vaccination schedule
--if unknown vaccination history, do not give to pregnant animal
-Longest lasting immunity, do not need to booster
-Strongly recommended for all young stock

Front 136

IBR Killed Vaccine

Back 136

-Safest vaccine
-few reactions
-no replication of the virus in the body
-2 doses are needed for initial immunity
-Need an annual booster (VERY important!)

Front 137

IBR Summary

Back 137

-Herpes virus
-high sero-prevalence, 80% of cattle have seen virus
-Not very pathogenic alone
--sets stage for bacterial infection
-WBC profile is normal
-White plaques on mucosa, esp. nasal passages
-Predisposes animal to bacterial pneumonia
--IMPORTANT with shipping!
--Shipping fever, weaning and shipping stress
-Has may syndromes
-Can cause abortions

Front 138

Parainfluenza Virus in Bovine
PI-3

Back 138

-Paramyxovirus
-90% seroprevalence in cattle
-Not pathogenic alone, will not cause a problem by itself in animals
-Very important in combination with pasteurella or Mannheimia bacteria
--Can lead to bacterial Pneumonia

Front 139

Clinical Signs of PI-3

Back 139

-Mild increase in respiratory effort
-No real definitive signs, all are non-specific

Front 140

PI-3 Vaccine

Back 140

-Included in all IBR vaccines
--easy to incorporate and animals react to vaccine well
--ALWAYS as a combo vaccine
-Provides short-term immunity
--3 months
-Don't need to booster, just give with IBR vaccine
-Can be useful before shipping

Front 141

Bovine Respiratory Syncytial Virus
BRSV

Back 141

-Paramyxovirus
-High sero-prevalence
--50-80% of cattle are seropositive
-NOT Bovine syncytial virus
-Latent infection is common and important
--can become latent even though it is a paramyxovirus
-Infection comes via aerosol from dam at birth
--calving is stressful for the cow, will shed virus and spread the virus to the calf
-Stress causes recurrence of the virus and emergence of disease later

Front 142

Diagnosis of BRSV

Back 142

-Serology is not useful
-Passive immunity is not protective
--colostrum is not helpful for calves
-Short incubation period, 3-5 days
-Highest incidence occurs between 2 and 5 months of age
--2 months= weaning in dairy
--5 months= weaning in beef

Front 143

Clinical Picture of BRSV

Back 143

1. Atypical Interstitial Pneumonia
--emphysema in interstitium of the lungs, air bubbles where there should not be any
2. ARDS
--animal is having problems exchanging air

-Subcutaneous Emphysema, air under the skin
-High fever
-No membrane changes, animal does not look toxic
-Big increase in salivation and saliva production
-May not have an increase in nasal or ocular discharge
-Slight increase in RR

Front 144

Treatment for BRSV

Back 144

-Animal can recover on own
-Also can go into respiratory distress a week or so later
--Mostly an issue with animals that are worked or stressed
--mortality rate increases with work/stress
-Can give antibiotic and NSAID or steroid

Front 145

BRSV Lungs

Back 145

-Whole lung mass is involved
-Lungs are over-inflated and push the ribs out
-Syncitial cells join membranes
--form one giant cell with multiple nuclei

Front 146

BRSV diagnosis

Back 146

-Difficult to make, hard to definitively culture organisms
-Virus is very fragile
-Virus is only present early in the clinical course of disease
-Can use fluorescent antibodies and immunohistochemisry to identify parts and pieces of a virus
-Virus isolation is not useful due to fragile virus
-Serology is not useful and difficult to interpret

Front 147

BRSV vaccination

Back 147

-Not clear if it actually works!
-Passive immunity is not protective
-Serum antibodies are not protective
-Killed and modified live vaccines are available
-Requires a booster
--need to challenge system again to get response
-Initially can give as combo vaccine
-Booster with specific BRSV vaccine

Front 148

Bovine Viral Diarrhea Virus
BVDV

Back 148

-Flaviviridae, pestivirus genus
-Major bovine pathogen
-Causes diarrhea, fever, mucosal erosions, abortions
-Predisposes animal to bacterial infection
-Immunosuppressive
-Causes oral ulcerations and erosions
-Persistent Infection, an infected animal is ALWAYS infected

Front 149

BVDV Persistently Infected Animals

Back 149

-Calf is exposed to virus in-utero at a very specific timeframe
-Fetus recognizes virus as "self"
-Animal can look normal and act normal, but spreads virus EVERYWHERE
-Any calves delivered will be PI calves
-Animal is persistently infected, will always be infected, and will never not be affected

Front 150

BVDV vaccination

Back 150

-Vaccination is effective
-Can be given as a combo vaccine

Front 151

Progression of Bovine Respiratory Infections

Back 151

-Poor management leads to viral infections that lead to bacterial infections

Front 152

Bovine Bacterial Bronchopneumonia

Back 152

-5 pathogens cause 95% of disease
1. Mannheimia haemolytica (#1 cause of bronchopneumonia)
2. Pasturella multocida
3. Histophilus somni
4. Mycoplasma bovis
5. Truperella pyrogenes (only gram+)
--most common abscess forming bacteria in all food animals

-Mostly gram- bacteria
-Cause issues in lower respiratory tract
--take out mucociliary escalator, allows bacteria to get into lower respiratory tract

Front 153

Gram- vs. Gram+ bacteria

Back 153

S.S. BECCLR DAMNT
-Staph
-Strep
-Bacillus
-Erisypilothrix
-Clostridium
-Corynebacter
-Listeria
-Rhodococcus
-Dermatophilus
-Arcanobacterium
-Mycobacterium
-Nocardia
-Truperella

Front 154

Bovine Bacterial Bronchopneumonia Pathogenesis

Back 154

-Endotoxin: all gram- bacteria have endotoxin as cause of disease
--kills bacteria and tissue around the bacteria
-Exotoxin
-Chemotactic factors and hemolysins
--stimulates complement system that destroys tissue
-Macrophage activity is decreased, leads to terrible infection

Front 155

Crackles in lung

Back 155

-Collapse of air sacs and bronchioles
-Need to open airways

Front 156

Wheezes in lung

Back 156

-Narrowing of airspace
--Stenosis
-Can be via collapse OR filling of lumen with mucus

Front 157

Bovine Respiratory Disease
BRD

Back 157

-Stress reduces host defense
-Virus damages upper respiratory tract
-Bacteria is able to invade lower respiratory tract
-Final outcome is bronchopneumonia
-Can be acute or chronic

Front 158

BRD Acute Bronchopneumonia

Back 158

-Mannheimia is primary pathogen
--high morbidity and high mortality
-pasturella multocida
--high morbidity, not as high mortality
-Histophilus somni

-Happens all of a sudden
-Bacterial infections are toxic, mucus membranes will change color (brick red)
-Endotoxins affect the entire body
-Will see weak animal with ocular and nasal discharge
-LOTS of damage to tissues in the lungs

Front 159

Factors leading to BRD Acute bronchopneumonia

Back 159

-Shipping fever
-Herd outbreak
-Sudden death
-Toxic animals
--purple or red mucus membranes
-Painful respiration due to pleuritis
-treat with antimicrobial!
-Common in shipped beef or weaned dairy, times of stress

Front 160

BRD Acute bronchopneumonia Necropsy Results

Back 160

-Fibrinous bronchopneumonia
-Antero-ventral lung consolidation
-May or may not have bulbous emphysema of the lung
-Fibrin tags cause friction rubs on the pleura
--fibrin turns into fibrous accumulations over time

Front 161

BRD Chronic Bronchopneumonia

Back 161

-Pasteurella multocida is most common
-Truperella pyrogenes, causes abscesses
-Histophilus somni
-Mycoplasma bovis

Front 162

Clinical Signs of BRD Chronic Bronchopneumonia

Back 162

-Small, stunted animal
-60% of lung tissue is compromised
-Milk production is down if animal makes it to parturition
-Often seen in younger animals
-Will have moist, productive cough
-Abnormal lung sounds
-Endemic or epidemic

Front 163

BRD Histophilus somni

Back 163

-Normal inhabitant of the upper respiratory tract
-Culture requires special media
-Serology is useful
-Difficult to diagnose in chronic situations

Front 164

BRD Mycoplasma

Back 164

-Can be Mycoplasma bovis or Mycoplasma dyspar
--Bovis causes most of the issues
-Mycoplasma mycoides in other countries
-No good treatment
-Mycoplasma is an intracellular organism
--hides from antimicrobials and immune system
-No vaccine available
-Looks like BSE or FMD

Front 165

Treatment of Chronic BRD

Back 165

-Long-term antibiotic therapy
--10 days or more
-Must start treatment early!
-Look for abscess

Front 166

BRD vaccination

Back 166

-Mannheimia and pasteurella are bacterins
--vaccination will not work
-useful against endotoxin
-Active endotoxin in vaccine can cause endotoxemia in cattle, have to be careful!

Front 167

BRD Best treatment

Back 167

-Prevention!
-Pre-condition animals with vaccines and immunostimulants

Front 168

Enzootic Calf Pneumonia

Back 168

-"Syndrome"
-Multiple pathogens present
-Chronic disease
-Due to poor ventilation and ammonia buildup
--ammonia leads to pneumonia
-Most common in heifers 2-6 months
-Recurrent
-Get better with treatment, but will continue to relapse of conditions are not changed

Front 169

BRD and antimicrobials

Back 169

-Treatment is all about antimicrobials
-Label use is best
-Can use some drugs off-label
--limited by feds
-Do not want any residues
-With-holds only apply if used on-label

Front 170

BRD Antibiotic treatment

Back 170

-Most commonly used:
--cephalosporin
--macrolide
--florfenicol
--oxytetracycline
-Least commonly used:
--beta-lactam (not very effective)
--Sulfas
--Rifampin (helps other microbials penetrate the bacterial cell wall

Front 171

Cephalosporin in Large Animals

Back 171

-Prohibited off-label or off-indication
-Naxcel
-Excenel
-Excede
-3rd generation
-Very effective against pasteurella multocida

Front 172

Naxcel

Back 172

-No milk with-hold
-4 day meat with-hold
-Pneumonia and foot rot

Front 173

Excenel

Back 173

-No milk with-hold
-3 day meat with-hold
-Pneumonia, foot rot, metritis
-Very effective against pasteurella multocida

Front 174

Excede

Back 174

-No milk with hold
-13 day meat with-hold

Front 175

Macrolide

Back 175

-Tilmicosin (micotil)
-Tulathromycin (Draxxin)
-Gamithromycin (Zactran)
-42 day meat with-hold, LONG with-hold
-NOT to be used in lactating dairy cows
--other better drugs are available
-Very toxic to humans an other animals
--do not use in swine or equine
--cardiac toxicity, kills myocardial cells

Front 176

Florfenicol

Back 176

-Nuflor
-Synthetic derivative
-Not for lactating cows
-28 day meat with hold
-Good activity against mannheimia haemolytica, Pasteurella multocida, Histiophilus somni

Front 177

Florfenicol and Flunixin meglumine

Back 177

-Resflor Gold
-Not for lactating cows
-38 day meat with-hold
-Basically NSAID and antimicrobial
-Good activity against Mannheimia haemolytica, pasteurella multocida, and histiophilus somni

Front 178

Fluoroquinolones

Back 178

-Endofloxacin (Baytril)
-Not for lactating cows
-28-day meat with-hold
-Good activity against Mannheimia haemolytica, pasteurella multocida, histophilus somni

Front 179

Oxytetracycline

Back 179

-Can be put into feed
-Many routes of administration
-Long-acting forms are available
-Often used in combination with other anti-microbials
-Long meat with-hold, 30 days
-Can be used in lactating cattle

Front 180

Beta Lactam

Back 180

-Procaine Penicillin G (PPG)
--Test for meat and milk with-hold
-Polyflex
--48 hour milk with hold, 6 day meat with hold

Front 181

Sulfas

Back 181

-Albon Bolus
-60 hour milk with-hold
-7 day meat with-hold

Front 182

BRD Non-infectious

Back 182

-Interstitial or Atypical Pneumonia

1. Acute Respiratory Distress Syndrome (ARDS)
2. Hypersensitivity
3. Chronic Interstitial Pneumonia
4. Parasitic Pneumonia

Front 183

ARDS anatomical changes

Back 183

-Pulmonary congestion or edema
-Hyaline membrane in alveoli
-Hyperplasia of alveolar epithelium
-Interstitial emphysema
-May find on necropsy
-need to find at least 1 in order to confirm ARDS

Front 184

ARDS syndromes

Back 184

1. Acute bovine Pulmonary Emphysema
--fog fever
2. Moldy Sweet Potato
3. Misc. toxicities
--Perilla mint toxicity
--NO

Quick changes in diet to lush grass from hay
-Microbes work on tryptophan, convert into 3-methyl indole
-3-methyl indole ends up in lung and destroys pneumocytes

Front 185

Acute Bovine Pulmonary Emphysema
ABPE

Back 185

-Fog Fever
-Occurs in Adult cattle
-Need a very specific history
--switch from dry to lush pasture
-Lush pasture has more tryptophan, increased tryptophan in diet
-Tryptophan is converted into 3-methyl-indole in rumen
-During eructation and rumination 3-methyl-indole gas ends up in the lungs
--causes vasoconstriction in the lungs

Front 186

ABPE Disease Progression

Back 186

-Acute onset
--occurs within 2 days of the switch
-Animal in respiratory distress
--head held out
--open mouth breathing
-Morbidity is high, all animals with the same diet change will be affected
-Normal temperature
-increased major airway sounds
-Diagnose by history and clinical signs

Front 187

ABPE Clinical Signs

Back 187

-No toxemia
-No increased temperature
-ON necropsy will see severe emphysema
-Lungs do not collapse
-Alveolar epithelial hyperplasia

Front 188

ABPE Treatment

Back 188

-Take cows off lush green pasture
-Give NSAIDs
-Give microbials to decrease bacterial infections

Front 189

Hypersensitivity Pneumonia

Back 189

-AKA
--proliferative pneumonia
--bronchiolitis obliterans
--chronic non-infectious interstitial pneumonia
-Same progress as "farmer's lung"
-Slowly progressive
-Due to chronic exposure to micropolysore molds
-Lung has immune-mediated response to mold or spores in hay
--Type III hypersensitivity
-Destruction of bronchioles
-Alveolar hyperplasia and fibrosis
--loss of alveolar sac

Front 190

Misc. Pneumonia

Back 190

-Necrotic laryngitis
-Metastatic Pneumonia
-Caudal Vena cava thrombosis
-Lung abscesses
-Inhalation/aspiration pneumonia
-Lungworm (Dictyocaulus viviparous)
-Iatrogenic pharyngeal abscesses
-Allergic rhinitis

Front 191

Necrotic Laryngitis

Back 191

-"Calf Diptheria"
-Fusobacterium necrophorum
-Occurs in 2-6 month old calves
-Need break in mucosa
--coarse feed or stemmy hay
--hay damages larynx
-Bacteria sets up shop in the damaged mucosa
-only seen in damp dark barns

Front 192

Necrotic laryngitis Clinical Signs

Back 192

-Upper respiratory obstruction
-Fetid breath due to necrosis and tissue death
-Respiratory stridor
-Can see lesions in the back of the mouth

Front 193

Metastatic Pneumonia

Back 193

-Low incidence
-Sporadic individual cases only
-No prior pneumonia history
-Most often seen in neonatal calves
--can occur secondary to E. coli septicemia

Front 194

Caudal Vena Cava Thrombosis Syndrome Pathology

Back 194

1. Rumen acidosis causes ulcerative damage to rumen wall
2. Bacteria invades lesions
3. Bacteria gets into the blood stream and spreads hematogenously to liver and causes abscesses in liver
4.Thrombi form and are released
5. Thrombi travel from hepatic vein to caudal vena cava to heart and lung
6. "Embolic shower" in the lungs, causes necrotic tissue

Front 195

Caudal Vena Cava Syndrome

Back 195

-Usually seen in cattle more than 1 year old
-Can be seen as increased RR
-Epistaxis (nose bleeds)
--once nose-bleed is seen, damage is done
-Very poor prognosis

Front 196

Allergic Rhinitis

Back 196

-"summer sniffles"
-Pastured mature cattle
-Localized immediate type I hypersensitivity
-Causes sneezing nasal pruritus
-Becomes granulomatous when chronic

Front 197

Diaphragm Function

Back 197

-Active Respiratory bellows
-Contracts, moves caudally and creates negative pressure in the chest cavity
-Chest moves cranially and dorsally
-Sub-atmospheric pressure overcomes airway resistance and elastic recoil of lung
-Diaphragm relaxes for expiration
--Allows for elastic recoil of the lung and chest wall

Front 198

Deviated Sternum

Back 198

-Can cause significant difficulty breathing for animal
-Fix by putting sutures around the ribs and sternum
--If placing suture around the sternum, start on the side with the heart

Front 199

Sternal Osteomyelitis

Back 199

-Looks like lytic sternebrae
-Could be neoplasia or infection
--Have to biopsy to know for sure

Front 200

Infective Pleuritis

Back 200

-Antibiotics do not work long-term
-Have to remove infected bone

Front 201

Bite wounds to the chest

Back 201

-Painful!
-Poor ventilation
-Substantial hemorrhage in the lungs can lead to bruising
--leads to poor ventilation and ventilation perfusion mismatch

Front 202

Hypoxia in Thoracic trauma

Back 202

-Secondary to pulmonary parenchymal disease, interpleural disease, and pain
-Pain causes hypoxia

Front 203

Flail Chest

Back 203

-Ribs broken in 2 places
-Segment moves paradoxically to inhalation/exhalation
-Treat animal for pain
-Can wire rib ends back together
-Can also sp

Front 204

Rib Neoplasia

Back 204

-Determine if chondrosarcoma cs. osteosarcoma
--Do not remove osteosarcoma
--chondrosarcoma removal has good prognosis
-Look for metastatic disease
-Will see displaced ribs with periosteal reaction on radiographs
--trachea may also be deviated

Front 205

Removing Rib Chondrosarcoma

Back 205

-Remove entire section of ribs
-Hard to close, have to use mesh and stitch mesh to body wall
-Put omentum over the mesh

Front 206

Septum transversarium

Back 206

-Forms central tendinous region of diaphragm
-Failure of fusion or incomplete formation results in peritoneo-pericardial hernia

Front 207

Holes in the Diaphragm

Back 207

1. Caval foramen: caudal vena cava
2. Esophageal Hiatus: esophagus
3. Aortic Hiatus: aorta, azygous vein, hemiazygous vein, lumbar cistern of the thoracic duct

Front 208

Anatomy of the Diaphragm

Back 208

-Musculotendinous partition
-Central tendinous section and 3 separate muscles
--costal
--sternal
--lumbar

Front 209

Embryology of the Diaphragm

Back 209

-Diaphragm originates from cervical region in the embryo
--C5-C7
-Origin of phrenic nerve roots is C5-C7
-Transverse septum eventually forms central tendon
-Dorsal mesentery of the esophagus forms crura of diaphragm
-Failure of fusion or no complete formation of transverse septum results in peritoneo-pericardial hernia

Front 210

Peritoneopericardial Hernias

Back 210

-Failure of the transverse septum to form properly or fuse medially
-Herniation of abdominal viscera into pericardial sac
-Sternal abnormalities
-Cranial abdominal wall defects
-Umbillical hernia
-Cardiac defects
-Usually have other mid-line defects
--VSD

Front 211

Surgical Repair of Peritoneopericardial Hernia

Back 211

-Clip all the way to the neck
--want to have option of entering thoracic cavity if necessary
-Usually will just be in the pericardial space, not pleural space

Front 212

Diaphragmatic hernia Causes

Back 212

-Mostly traumatic (77-85%)
--kicked, hit by car
-5-10% are congenital
-Few are unknown cause
-Sudden increase in intra-abdominal pressure with glottis open will cause herniation
--Normal pressure is 7-20cm
--greater than 100cm will cause herniation

Front 213

Diaphragmatic Hernia Types

Back 213

-Male dogs 1-3 years old are greatest risk
-Costal muscles are most frequently ruptured
-Circumferential rupture 40%
-Radial rupture 40%
-Combination 20%

Front 214

Diaphragmatic Hernia Sequelae

Back 214

-Interferes with cardiorespiratory function
--things in thorax that should not be there prevent lung from inflating fully
-Incarceration, strangulation, or obstruction of bowel
-Hepatic venous stasis due to pressure change
-Necrosis
-Bile stasis

Front 215

Downward spiral of Diaphragmatic Hernia

Back 215

-Dyspnea causes swallowing of air
-Air in stomach inflates stomach, stomach takes up more space in thoracic cavity
-Less space for lungs to expand, more dyspnea
-More dyspnea, more air is swallowed

Front 216

Clinical Signs of Diaphragmatic hernia

Back 216

-No clinical signs are pathognomonic
-Dyspnea and exercise intolerance present in 40% of cases
-GI signs including vomiting and weight loss are common
-ON Auscultation heart sounds are muffled or louder on one side compared to the other

Front 217

Radiographic Signs of Diaphragmatic hernia or issues

Back 217

-Cannot see the line of the diaphragm where it should be
-Can see gas or intestines in the thoracic cavity
-Can do sterile water-soluble iodine contrast study
--inject iodine into the abdomen, and if it ends up in the thoracic cavity something is wrong
--Abdominal cavity should not communicate with the thoracic cavity
-Barium swallow with fluroscopy

Front 218

Diaphragmatic hernia Surgery

Back 218

-Higher mortality of surgery is performed within 24 hours of injury?
-Only an emergency procedure if severe cardio-respiratory compromise occurs
-If you can't get something to go where you want it to, make a bigger hole
--do not pull harder, may be fused to a delicate structure

Front 219

Anesthesia for Diaphragmatic hernia cases

Back 219

-Do not forcibly reinflate lungs that have been chronically collapsed due to changes in pressure!
-Will result in reperfusion pulmonary edema
-Keep at 10-15cm H2O
-Need someone who is good at anesthesia, need to be prepared for collapsed lungs with diaphragmatic hernia surgery

Front 220

Post-operative Management of patient with Diaphragmatic hernia

Back 220

-Respiratory Function: monitor and treat
-Chest tube management
-Pain
--epidural catheter
--intrapleural bi

Front 221

Hiatal hernia

Back 221

-Stomach slides up into the chest cavity
-Usually occurs because esophageal hiatus is too big
--should be small enough to prevent stomach from moving into the thorax
-Zone of high pressure at distal end of esophagus (caudal esophageal sphincter) also prevents movement
-Diaphragmatic crus, angle of the esophagus at the cardia, gastric mucosal folds, and phreno-esophageal membrane also prevent movement
-Can be congenital, post-traumatic, or due to respiratory onstruction

Front 222

Clinical signs of Hiatal hernia

Back 222

-GI signs: vomiting and regurgitation
-Abnormal/decreased esophageal motility
--Occurs secondary to GE reflux and esophagitis?
-Aspiration pneumonia

Front 223

Upper airway Obstruction and Diaphragmatic hernia

Back 223

-Severe upper airway obstruction can cause a change in pressure
-Decreased pressure at caudal esophageal sphincter will allow stomach to be pulled into chest cavity

Front 224

Diaphragmatic hernia Important factors

Back 224

-Underlying disease?
-Is animal showing clinical signs?
-Loss of functinon of caudal esophageal sphincter?
-Reflux esophagitis?
-Esophageal ulceration?
-Is medical treatment working?

Front 225

Thoracic Surgery in the Small Animal

Back 225

-Often done in clinical veterinary practice
-Indications:
--repair congenital and acquired cardiac defects
--esophageal conditions
--diseases of the conducting airways
--Pulmonary and pleural disease
--Conditions of the thoracic wall

Front 226

Special considerations for Thoracic Surgery

Back 226

-Surgeon needs intimate knowledge of anatomy and physiology of the thorax and associated structures
-Need special attention with anesthesia
-Procedures are technically challenging, but can be very rewarding

Front 227

Bite wound with Normal thoracic Radiographs

Back 227

-Mild dyspnea
-No evidence of pneumothorax
-No evidence of pulmonary contusions
-Can stabilize and re-check
-Normal thoracic radiographs do not rule out substantial thoracic pathology in bite wound cases
--bite wounds do not show up on radiographs!

Front 228

History of the patient with thoracic disease

Back 228

-Change in respiratory effort
-Change in attitude (more lethargic)
-Change in appetite
-Vomiting or regurgitation
-Weight loss
-Need to check out heart and respiratory systems both

Front 229

Physical Examination of a Patient with thoracic disease

Back 229

-CRT, compare crainal and caudal aspects of the body
-Arterial pulse rate and quality
-Jugular venous distention or pulsation
-Auscultation of the thoracic cavity
-Tracheal irritation

Front 230

Cyanosis and Hb curve

Back 230

-Cyanosis occurs when 33% of Hb is unsaturated
-Pulse Ox will be 66!
-BAD news! very poor perfusion!

Front 231

Diagnostic tests for patient with thoracic disease

Back 231

-CBC/Chem
-Thoracic radiography

Front 232

Pre-operative considerations for a patient with Thoracic Disease

Back 232

-Stabilize cardiac disease prior to surgery
-Tap pneumothorax and pleural effusion before surgery
-Restrain animal with caution, struggling increases O2 consumption
-Take pre-operative arterial blood gas to rule out pneumonia or pulmonary metastatic disease in hypoxic animals

Front 233

Pre-operative considerations for patient with Thoracic Disease

Back 233

-Perioperative antimicrobial drugs
-Availability of blood products
-Owners give informed consent
-Well-prepared and capable anesthesiologists
-Well-prepared and capable OR staff
-Appropriate instruments and skill level of surgeon

Front 234

Anesthesia of a patient with Thoracic Disease

Back 234

-Give supplemental O2
-Rapid induction and intubation
-Monitor closely with pressure gauge, BP monitor, and venous access
-Epidural with straight morphine can give good pain relief

Front 235

Effects of Thoracotomy

Back 235

-Loss of negative intrapleural pressure prevents normal lung expansion and decreases venous return to the heart
--need sub-atmospheric pressure for venous return to the heart
-Positive-pressure ventilation restores ventilation
--further decreases cardiac return
-Will have atelectasis of dependent lung

Front 236

Thoracic Wall Anatomy

Back 236

-13 pairs of ribs
--Ribs 1-9 articulate with sternum
--ribs 10-12 form costal arch
--13th rib is "floating"
-Intercostal muscles
-Latissimus dorsi
-Serratus ventralis, serratus dorsalis
-External abdominal oblique muscle
-Scalenus

Front 237

Common surgical approaches to the thoracic cavity

Back 237

-Lateral intercostal thoracotomy
-Lateral thoracotomy with rib resection
-Median sternotomy
-Trans-diaphragmatic
-Trans-sternal
-Rib pivot

Front 238

Lateral Intercostal approach to Thoracic Cavity

Back 238

1. Skin incision
2. Latissimus dorsi incision
3. Scalenus incision and elevation
--attached to the 5th rib
4. Serratus incision and elevation
5. Intercostal incision
6. Pleural incision

Front 239

Lateral Intercostal Closure

Back 239

1. Place thoracostomy tube
--secure properly with careful connections
2. Pre-place 4-6 circumcostal sutures
3. Use rib approxmator or tension on sutures
4. Repair muscles cut during approach
5. Aspirate thoracostomy tube once a seal is formed
6. Light bandage after skin closure

Front 240

Lateral Rib Resection

Back 240

-Remove a rib for more room
-Enter as for a lateral intercostal thoracostomy
-Elevate periosteum and cut rib
-Incise periosteum and parietal pleura
-Close periosteum and pleura with simple interrupted sutures

Front 241

Median Sternotomy

Back 241

-Useful when need to get to both sides of the chest
-Ventral midline skin incision
-Divide pectoral muscles along the midline
-Incise the sternebrae exactly down the midle
-Leave either caudal or cranial 2 sternebrae intact when possible
-Close sternum securely with 18 gauge surgical wire

Front 242

Post-operative care and monitoring of a Thoracotomy patient

Back 242

-Balanced electrolyte solution at 4-8 ml/kg/hour
--fluid replacement therapy
-PCV/TS/Azo/Dextrose every 4-6 hours
-Arterial blood pressure
-Mucous membranes and CRT
-Aspirate chest tube every 2-4 hours or put on continuous pleural drainage
--5-10 ml/kg/day
--if getting blood out, check PCV, low PVC no big deal
-Check respiration rate and effort
-Urine production
-Continuous or intermittent ECG
-Arterial blood gas to check ventilation, pulmonary function, and acid/base
-Pulse oximetry and O2 saturation
-Auscultation of the chest
-Continue analgesic protocol, manage pain
-Nutritional support of needed (feeding tube)
-Encourage ambulation or turn patient regularly to improve ventilation
-Gradually reduce intensity of care and animal improves

Front 243

Observing Equine Respirations

Back 243

-Eyes and ears are key
-Check respiratory effort
--depth
--inspiration vs expiration
--paradoxical breathing
--Asymmetrical breathing
-Stridor and Stertor
-Check mucous membranes
--should be pale pink

Front 244

Stethscope as a tool for Equine Respiratory Assessment

Back 244

-Sensitivity is poor in the adult, animal is too big
-Foal auscultation is fair to good
-Can use re-breathing exam to induce respiratory sounds
--Hypercapnia (NOT hypoxia)
--Increases respiratory depth and rate

Front 245

Normal Equine Respiratory Auscultation

Back 245

-Should hear bronchovesicular sounds
-Should not hear crackles, wheezes, radiating heart sounds
-Inspiration should be bigger than expiration
-Dorsally sounds should be suiet
-Increased RR will increase level of respiratory noise

Front 246

Radiating heart sounds

Back 246

-Indicates pleural fluid is present
-Fluid allows radiating heart sound

Front 247

Ultrasound for Equine Respiratory Evaluation

Back 247

-Very good at evaluating the pleura
--pleural effusion
--Superficial abscesses
--Consolidation of alveoli
--Pneumothorax
-Easy to do!
-Poor for aerated parenchyma
-If lung is filled with gas, cannot see anything on ultrasound

Front 248

Ultrasound Specifics

Back 248

-2 White lines: pleural surfaces
--slide against each other when the animal breathes
-As lungs become less aerated and more consolidated, will see more details on ultrasound
--comet-tails
--abscesses
--consolidated lung
--Pleural effusion and fluid

Front 249

"Triangle of Death"

Back 249

-Caudodorsal aspect of equine lung
-If animal is sick, will just see a small triangle between vena cava, diaphragm, and heart silhouete
-Bad news! Indicates disease!

Front 250

Trans-Tracheal Wash

Back 250

-Test for bacterial Pneumonia
-Good test if disease is in specific part of the lung, will get effluent from entire lung
--focal lung disease
--gets a pooled sample from the entire lung
-Best sample for culture
-Use needle or endoscope, put sterile saline into lungs at carina and aspirate

Front 251

Bronchoalveolar Lavage
BAL

Back 251

-Use for Heaves, EIPH, fungal pneumonia, silicosis
-Put scope or Bivona tube into distal bronchus
--add large aliquot of saline and aspirate
-Only samples a random, small portion of the lung
-Great for GLOBAL lung disease
--ideally the whole lung is affected in the same way, so any focal sample will have the same bugs
-NOT a sterile procedure

Front 252

Pulmonary Function Testing

Back 252

-Tests for Recurrent Airway Obstruction or inflammatory Airway Disease
-Shows how "twitchy" airways are

Front 253

Lower Airway Disease

Back 253

1. Infectious
--viral, bacterial, fungal
--Most common lung disease
2. Inflammatory
--recurrent airway obstruction/Heaves
--Inflammatory Airway Disease
3. Toxic
--perilla mint, silicosis
4. Neoplastic
--primary or metastatic neoplastic disease

Front 254

Equine Influenza

Back 254

-Influenza A virus, H3N8 strain
-Lots of genetic divergence, makes vaccination difficult
--be sure to use most current vaccine when vaccinating
-Generally affects young animals
-48 hour incubation period
-Rarely fatal
-Treatment: rest!
--one week for every day of fever
--virus will resolve on its own with rest
--DO NOT give antibiotics unless concurrent bacterial infection is present

Front 255

Equine Influenza Clinical Signs

Back 255

-Thin nasal discharge
-Cough
-Temperature, febrile patient
-Crackles in lung
-Increased RR

Front 256

Things Contributing to a Problem List

Back 256

-History
-Physical Exam
-Bloodwork

Front 257

Equine Influenza Diagnostics

Back 257

-Ultrasound: should see comet-tails indicating pleural roughening
--fibrin tags, thick pleura
-Radiographs
-Nasal Swab

Front 258

Equine Influenza Control

Back 258

-Vaccines are generally poor, not very useful
--short duration, high genetic variation
-intranasal and IM vaccines exist
-Start foal vaccination at 6 months
-Be sure to give most recent version of the vaccine for most effective protection!

Front 259

Equine Herpes Virus 1 and 4

Back 259

-Looks a lot like equine influenza on clinical presentation
-EHV 4 is less severe, respiratory signs only
-EHV 1 can cause abortion storms, neonatal death, myeloencephalopathy
-Reportable disease! REPORT!!

Front 260

Equine herpes Virus Clinical Presentation

Back 260

-Looks a lot like Equine Influenza
-Biphasic fever
-Cough, nasal discharge
-EHV4 can also have abortion storms, neonatal death, myeloenceophalopathy

Front 261

Equine herpes Virus Pathogenesis

Back 261

-Infects Respiratory epithelium
-Causes lymphocyte viremia
-Latency in lymph nodes
-Most horses are seropositive
-Young adults are very contagious

Front 262

Equine Herpes Virus Treatment

Back 262

-Rest, rest rest!
--one week for every day with fever
-Do not give antibiotics, will not do anything
-Vaccine for control, give every 6 months
--inactivated IM injection is generally poor with short protection
-EHV1 vaccine cross-protects with EHV4 vaccine

Front 263

Equine Herpes Virus 2 and 5

Back 263

-VERY common, mild signs
-Are present on diagnostic panels
-EHV5 is very common and really not a big deal
-Will show up on nasal swabs regularly

Front 264

Equine Rhinitis Virus A and B

Back 264

-Very common
-Most horses are seropositive by early adulthood
-Mild clinical signs, mild transient outbreaks
-New vaccine exists

Front 265

Equine Respiratory Viruses

Back 265

-Equine Influenza Virus
-Equine Herpes Virus 1 and 4
-Equine Rhinitis Virus A and B

-Viruses kill mucociliary escalator
--no primary defense system for the lungs anymore
--Have to take time to grow back ciliated epithelial cells
-Does not normally result in pleural effusion

Front 266

Equine Pleuropneumonia

Back 266

-Pleural tissues AND lung parenchyma is affected

Front 267

Equine Pleuropneumonia Clinical Signs

Back 267

-Anorexia
-Nasal discharge
-Cough can be present sometimes, not consistent
-Fever
-Tachypnea, increased RR
-slightly Increased HR
-Pleural pain that can look like colic (fake colic)
-Pleural effusion is often present
-Crackles can be heard

Front 268

Equine Pleuropneumonia Diagnostic tests

Back 268

-CBC, should see increased fibrinogen and neutrophils
-Ultrasound
-Radiographs
-TTW: should see severe suppurative inflammation
--degenerate neutrophils
--intra and extra-cellular bacteria
-Culture TTW

Front 269

Klebsiella pneumoniae in Horse TTW

Back 269

-Scope contaminant
-Can cause disease, but will probably be present on culture anyway

Front 270

Pleuropneumonia Pleural Fluid

Back 270

-Often will have different organisms present compared to TTW
-Glucose should be low, bacteria eat glucose
-pH will be low, bacteria make environment more acidic

Front 271

Equine Pleuropneumonia Treatment

Back 271

-Antibiotics
--broad spectrum until culture results are available
-NSAIDS in 1st 48 hours
--careful of stomach, kidneys
--careful to mask fever, need to know if antibiotics are working
-Thoracic drains can be used if necessary
--also provide nidus for infection and prevents proper ventilation
-Supportive care, esp. calories!
-Antibiotics, NSAIDS, Hydration, Calories

Front 272

Equine Pleuropneumonia Antibiotic Choice

Back 272

-Start with broad-spectrum antibiotic
-4 quadrant coverate
--gram+/gram-
--anaerobic/aerobic
-No need for enrofloxacin, no strep zoo effect

Front 273

Equine Pleuropneumonia and Thoracic Drains

Back 273

-May be necessary with lots o pleural effusion
-Heimlich valve allows one-way drainage
-Fibrin can clog tubes, have to put in new tube if clogged
-Sometimes fibrin gets to bad lung is glued to chest wall

Front 274

Pleuropneumonia end of treatment

Back 274

-Can be treated for months
-Re-check with radiographs and ultrasound
-Normal fibrinogen or WBC count
-Mild cases usually take 1-3 weeks of treatment
-Absecesses or necrotic lungs can take 1-6 months to treat
--can cost more than $5,000
--must be committed!

Front 275

Equine Pleuropneumonia Epidemiology

Back 275

-82% of cases occur in young patients
-Often occur after shipping (main risk factor)
-Esophageal obstruction is also possible
-Anesthesia
-Recent viral infections

Front 276

Strangles
Strep equi equi

Back 276

-Occurs in 1-3 year old horses most often, but can occur in any age
-Highly contagious!
-Lymphadenopathy, fever, nasal discharge are main signs

Front 277

Strangles/Strep equi equi Clinical Signs

Back 277

-Fever, nasal discharge
-lethargic
-Purulent nasal discharge
-Sumbandibular/retropharyngeal lymphadenopathy
--swollen lymph nodes
--pathognomonic for strangles
-Blood work:
--high neutrophil count
--high fibrinogen, more than 1,000 indicates ABSCESS

Front 278

High Fever in horses

Back 278

-Virus
-Rikketsial disease
-Primary bacterial disease

Front 279

Nasal Discharge in Horses

Back 279

-Pneumonia
-Viral upper respiratory tract infection
-Heaves
-Strangles/strep equi equi

Front 280

Diagnostic plan for Strangles/Strep equi equi

Back 280

-Aspirate lymph nodes
--gram+ cocci in singles, pairs, and chains
-PCR/culture is main diagnostic tool`

Front 281

Strangles/Strep equi equi pathophysiology

Back 281

-Gram+ cocci
-VERY contagious!
-Spread by inhalation or ingestion
-Fomites can also spread
--buckets, water troughs, humans, vets
-Not very persistent in the environment
-Some horses can become persistent shedders
--reservoir in gurrural pouch
--can rule out persistent shedder with 3 negative flushes

Front 282

Strangles/Strep equi equi treatment

Back 282

Mild: let disease run its course
-Fever, mild anorexia, no respiratory distress
-Symptomatic therapy
-Drain amscesses
-Cautious NSAID use

Severe: antibiotics
-Animal is in respiratory distress, can to tracheostomy
-drain abscesses
-Give penicillin (kryptonite for strangles!)

Front 283

Prevention of Strangles/Strep equi equi
Environmental

Back 283

-Isolate affected horses until negative
-Use excellent hygiene
-Identify persistent shedders/carriers
-75% of animals are immune after being infected

Front 284

Prevention of Strangles/Strep equi equi
Vaccine

Back 284

-IM injection is not very effective
-Intranasal modified live vaccine is more effective
--give as last vaccine if giving multiple vaccines
-Do not give during an outbreak
--give a year later
--animal has good post-infection immunity
--increases risk of purpura

Front 285

Strangles/Strep equi equi Complications

Back 285

-Metastatic Streptococcus Equi
--bastard strangles
--10% of strangles cases
--Can cause Abscesses in the abdomen, brain, liver, spleen, kidneys, etc.
-Guttural Pouch empyema or chondroids

Front 286

Bastard Strangles

Back 286

-Dx:
--strep M protein titer
--inflammatory blood work
--history
--ultrasound, CSF tap
-Tx:
--long-term antibiotics, 1-6 months
--Penicillin

Front 287

Immune Mediated complications of Strangles/Strep equi equi

Back 287

1. Purpura hemorrhagica
--vasculitis and severe edema
--Treat with steroids and penicillin
2. Streptococcal myositis
--infarcts
--rhabdomyolysis with atrophy in quarter horses

Front 288

Equine Interstitial Pneumonia

Back 288

-Totally hazy chest radiographs
-Can't see vessels at all
-Infiltrate or fluid in lung parenchyma
-May see dense milliary pattern
-DDx:
--fungal pneumonia
--Neoplasia

Front 289

Fungal Hyphae in Lungs

Back 289

-Can't really see on tracheal wash
-VERY important when seen on BAL

Front 290

Fungal Pneumonia

Back 290

1. Primary: specific fungal pathogens present
--Caused by specific fungal pathogens
--based on discrete geographical locations
--Animal must live or have traveled to these areas
2. Opportunistic/secondary fungal infection:
--immunocompromised animals
--Aspergillus and other environmental species

Front 291

Primary Fungal Pneumonia

Back 291

-Blastomyces dermatiditis
-Coccidoides immitis
-Cryptococcus neoformans
-Histoplasma capsulatum

-Non-specific clinical signs
--weight loss, exercise intolerance, cough
-History of travel to endemic area is key

Front 292

Primary Fungal Pneumonia Dx and Tx

Back 292

-Dx: must get travel history!
--radiographs, BAL, biopsy
--Serum titers only show exposure, not infection
-Tx: systemic anti-fungals
--very expensive!
-Generally poor prognosis

Front 293

Fungal Hyphae in Tracheal Wash TTW

Back 293

-Do not over-interpret!
-Up to 70% of animals have evidence of fungal elements
-Normal finding!
-Do not treat with antifungal medication unless good evidence for real fungal pneumonia
-Good evidence:
--large numbers of intra and extra cellular fungal elements
--consistent radiographic changes

Front 294

Opportunistic Fungal Pneumonia Organisms

Back 294

-Aspergillus
-Candida
-Fusarium
-Pneumocystis carinii (immunocompromised animals)

Front 295

Opportunistic Fungal Pneumonia

Back 295

-Usually occurs in immuno-compromised individuals
--cancer
--recent GI disease
-generally rare occurrence
-Clinical signs include cough, tachypnea, fever, adventitial lung sounds, nasal discharge

Front 296

Opportunistic Fungal Pneumonia Dx, Tx

Back 296

-Dx with radiographs, BAL, biopsy
-Can test immune function of the animal
-Tx: systemic anti-fungals
--SMZ-TMS for pneumocystis in foals
-Prognosis is generally poor

Front 297

Interstitial Pneumonia

Back 297

-Rare!
-NOT COMMON!
-Clinical signs are severe
-Can be secondary to sepsis
-Usually idiopathic
-Inflammation in the lung interstitium

Front 298

Clinical signs of Interstitial pneumonia

Back 298

-Severe clinical signs!
-Tachypnea
-Cyanosis
-Fever
-Cough
-Weight loss

Front 299

Diagnosis of Interstitial Pneumonia

Back 299

-Radiographs: Diffuse pattern
--looks like ground glass
--miliary, little grains everywhere
--Nodular pattern possible
-BAL, look for DDx of fungal or neoplastic cells
-Lung biopsy

Front 300

Etiology of Interstitial Pneumonia

Back 300

1. Infectious
--acute is viral or bacterial
--Systemic inflammation, ARDS
--EHV5
--Equine Multi-nodular pulmonary fibrosis
2. Silicosis
3. Toxins: perilla mint from hay
4. Idiopathic

Front 301

Interstitial Pneumonia Treatment

Back 301

-Corticosteroids
-Anti-virals

Prognosis is guarded to poor, 25% success

Front 302

Rhodococcus equi

Back 302

-Occurs mostly in foals 1-6 months
-Will have respiratory signs AND extra-pulmonary disease
-Main clinical sign is chronic suppurative pneumonia with abscessation

Front 303

Pulmonary Signs of Rhodococcus equi

Back 303

-Fever
-Tachypnea
-Adventitial lung sounds, crackles and wheezes
-Death!
--On necropsy, will see big abscess nodules in lung parenchyma

Front 304

Extrapulmonary clinical signs of Rhodococcus equi

Back 304

-Diarrhea
-Colic
--Typhlitis, inflammation of the cecum
--Enterocolitis
-Lymph node abscesses
-Uveitis
-Polysynovitis
--not lame, just swollen joints
-Septic arthritis or osteomyelitis
--rhodococcus seeds into the joints

Front 305

Rhodococcus Diagnosis

Back 305

-Cytology: look for gram+ pleomorphic rods
-Culture
--growth in a dish indicates it is a live organism
-PCR: VapA specific
--may be too sensitive, VapA is present in dirt
-No serology, no correlation between a positive titer and clinical disease

Front 306

Rhodococus Pathology

Back 306

-Gram+ cocobacillus
-Ubiquitous soil organism, present everywhere
-Inhaled into the lung early in life?
-Intracellular organism
-Shed in feces
-Virulent strain is VapA positive
--2-23% of all environmental isolates
-Not very contagious

Front 307

Rhodococcus treatment

Back 307

-Long-term antibiotics, gram+
-Macrolides with or without rifampin
--azithromycin
--Clarithromycin
--Tulathromycin
-Some resistance is appearing!
-May have co-infection and need to add gram- coverage

Front 308

Venner and Rhodocoddus pulmonary absecesses

Back 308

-Abscess lesions less than 1-10cm do not recover faster with antimicrobials
--do not treat if abscesses are smaller than 10cm!
--Contributes to resistance

Front 309

Rhodococcus Prevention

Back 309

-Screening
-Environmental management (not proven to be effective)
-Chemoprophylaxis
-Passive immunization (very expensive!)
--hyper-immunized serum on days 1 and 30
-Vaccination has not been proven to be effective

Front 310

Foal Pneumonia

Back 310

-Neonatal pneumonia
-1-6 year old foals
--strep equi zooepidemicus, gram+ coccus (normal commensual bacteria in upper airway)
--Rhodococcus equi, gram+ coccobacilli
-Sporadic presentation
-Clinical signs: fever, tachypnea, adventitial lung sounds, hypoxemia, nasal discharge, depression

Front 311

Foal Pneumonia Dx

Back 311

-Radiographs, ultrasound
-TTW, culture
-Inflammatory leukogram
-Increased fibrinogen

Front 312

Foal Pneumonia Tx

Back 312

-Broad spectrum antibiotics
-Ensure Strep coverage
--Penicillin
--Cephalosporins
--SMZ-TMS
--Macrolides

Front 313

Foal Pneumonia Radiographs

Back 313

-Air bronchograms will be present
-Cranioventral lung disease

Front 314

Recurrent Airway Obstruction
RAO

Back 314

-AKA Heaves
-Occurs in older horses, 6+
-Asthma of horses
-Horse will NOT die of heaves!
--human CAN die from asthma attack
-Controllable, not curable disease

Front 315

Recurrent Airway Obstruction Clinical Signs

Back 315

-Severe, episodic occurrences of difficulty breathing
-Expiratory effort due to stiff lungs
-Cough
-"Heave line"
-May or may not have nasal discharge

Front 316

Inflammatory Airway Disease

Back 316

-Airway disease second to musculoskeletal injury
-Occurs in 11-50% of thoroughbred and standardbred race horses
-Huge issue in young to middle-aged horses
-Controllable but not curable disease

Front 317

Inflammatory Airway Disease Clinical Signs

Back 317

-Cough
-Tracheal mucus
-Exercise intolerance
-No episodic dyspnea

Front 318

Inflammatory Airway Disease Diagnosis

Back 318

-Normal physical exam
-No consistent signs on radiographs
-Exercise intolerant on treadmill
-Tracheal mucous on endoscopy
-May have low blood oxygen after exercise

Front 319

Pathophysiology of Recurrent Airway Obstruction and Inflammatory Airway Disease

Back 319

-Environmental toxins
--dust, mold, endotoxins from manure
-Allergies
--summer pasture associated heaves
-Genetics: warmbloods

Front 320

Allergies and Recurrent Airway Obstruction and Inflammatory Airway Disease

Back 320

-Skin test: variable results, controversial
-Serum allergy test
--RAST, IgE based ELISAs
--Not useful for screening for allergen hypersensitivity in horses
-Measuring air quality may be helpful, horse may be in a toxic environment
-DO NOT LET HEAVEY HORSES NEAR STRAW

Front 321

Heavey horse exposed to trigger

Back 321

1. Sensitivity of the horse triggers episode
2. Airways are hyper-reactive "twitchy"
--triggers cause more bronchospasms, make it hard to breathe
3. Airways become inflamed
--neutrophils and pus accumualte in the small airways
--airways can become scarred and unable to open
4. Airways become blocked
--mucus becomes sticker and stays in airways
--bronchospasm makes it hard to breathe

Front 322

BAL and Inflammatory Airway Disease vs. Recurrent Airway Obstruction

Back 322

1. Normal BAL:
--neutrophils are less than 5%
--Eosinophils are less than 0.5%
--Mast cells are less than 2%
--rest are lymphoctes and macrophages
2. IAD:
--more than 5% neutrophils
--more than 0.5% eosinophils
--more than 2% mast cells
3. RAO:
--usually more than 25% neutrophils

Front 323

Treatment of Inflammatory Airway Disease and Recurrent Airway Obstruction

Management

Back 323

-Decrease dust, hay, and allergens present
--get horse away from the triggers
-Turnout all day
-Leave horse out of stall for more than 2 hours after cleaning, let dust settle
-Ensure good ventillation
--put horse in stall b door, no hay stored overhead
-Soak hay before feeding
-Put horse on shavings, not straw
-Avoid summer pasture?

Front 324

Treatment of Inflammatory Airway Disease and Recurrent Airway Obstruction

Corticosteroids

Back 324

-Great treatment for inflammatory disease
-Oral steroids induce remission, are most effective
--Prednisolone or dexamethasone
-Can also go inhaled steroid route
--maintain remission
--very expensive but with fewer side effects
--Not best for a crisis

Front 325

Treatment of inflammatory Airway Disease and Recurrent Airway Obstruction

Bronchodilators

Back 325

-Not to be used as sole treatment
-Albuterol, slameterol, ipratroprium
--cannot give albuterol orally, not bioavailable
-Use 30 min before exercise or before steroid puffer
-Do not give clenbuterol for more than 14 days unless combined with steroids
--B2 agonist
-Atropine can be used as rescue therapy
--can cause severe colic, only give 1 dose

Front 326

Equine Epistaxis

Back 326

-Unilateral vs. bilateral?
-Chronic, acute, or recurrent?
-Recent speed work?
-Amount of blood is important

Front 327

Exercise-induced Pulmonary Hemorrhage
EIPH

Back 327

-Huge problem in equine industry
-Occurs in horses that run fast
-More common in older horses vs. younger horses
-80-87% of horses have some EIPH
--pretty common after exercise
-Severe bleeding can lead to secondary bacterial infection
-Multi-factorial condition
--involved airway, vascular, cardiac, locomotory componentds
--Contribution of different factors varies between individuals and even in same horse over time

Front 328

EIPH clinical Signs

Back 328

-Tracheal blood after exercise
-Epistaxis in severe cases
-Rarely results in death
-May cause poor performance

Front 329

EIPH Pathophysiology

Back 329

-Alveolar capillaries in caudodorsal lung burst
--capillaries from pulmonary circulation
1. Due to increased transmural pressure
--increased pulmonary artery pressure during exercise combined with very negative pleural pressure during exercise
--pressure differential between pulmonary arteries and pleural pressure causes rupture
2. Locomotory Pressures
--Forelimbs have no bony attachment to axial skeleton
--Forces transmitted while galloping creates shear stress and capillary disruption
--maximum pressure over caudodorsal lung field

Still pretty unknown pathogenesis

Front 330

EIPH Diagnosis

Back 330

-Blood in the trachea 30-120 minutes post-exercise for 1-3 days
-BAL will show RBCs for up to 7 days
--Hemosiderophages for more than 21 days, macrophages are removing RBCs
-Radiographs are not sensitive
--may see opacity in caudodorsal lung field (indicates hemorrhage in alveoli)

Front 331

EIPH and Performance

Back 331

-More speed leads to more bleeding?
-Newer studies suggest that EIPH limits performance in thoroughbreds
-EIPH associated with better performance in standardbreds

Front 332

EIPH Treatment

Back 332

-Lots of treatments available
-Furosemide/lasix
--give before a race
-Dehydration
--reduces blood volume, decreases pulmonary alveolar pressure
--reduces weight so horses run faster
--Also increases blood viscosity, may lead to more shear force?

Front 333

Furosemide and EIPH

Back 333

-Furosemide decreases incidence and severity of EIPH in thoroughbred horses
-No indication as to how it affects speed!

Front 334

Equine Pulmonary neoplasia

Back 334

-Rare in horses
-Usually occurs in old horses
-Non-specific clinical signs
-Diagnose with radiographs, ultrasound, or biopsy
-Primary neoplasia is rare, secondary neoplasia is more common
--melanoma
--gastric squamous cell carcinoma
--hemangiosarcoma

Front 335

Equine Pulmonary Neoplasia Treatment

Back 335

-Palliative care
-Corticosteroids for lymphoma
-Get oncology consult

Front 336

Cough

Back 336

-Sign, not a diagnosis
-Sign of airway disease
-Can be a diagnostic and therapeutic challenge
-Acute cough vs Chronic cough
--chronic cough lasts more than 2 months

Front 337

Pathophysiology of Coughing

Back 337

-Non-specific response to airway inflammation or stretch
-has lots of triggers
-Viral, bacterial, parasite infections
-Allergic hypersensitivity reactions
-Foreign material
-External compression, something pressing on the airway
-Structural abnormalities, collapsed trachea
-Cough reflex backs up other airway protective mechanisms
--reflex removes exudates or foreign material from lungs

Front 338

Cough Reflex

Back 338

-Triggered locally in airways
-Controlled by cough centers in the brainstem
-Can treat locally in airway or in brainstem
-Occurs at maximal inspiration
-Initial forced exhalation against a closed glottis
-Sudden opening of the glottis produces rapid expulsion of air under pressure
-Simultaneous contraction of bronchial smooth muscle narrows airways, increases force of expulsion of material
-moves stuff crainially to mouth to be swallowed

Front 339

Types of Coughing

Back 339

-Have to hear cough so it can be categorized
-Productive cough:
--soft, moist
--often followed by swallowing
--helpful cough! Getting stuff to move up and out
-Non-productive cough
--harsh, high-pitched, honking cough
--loud and rough
--Paroxysmal
--not helpful to the animal, want to suppress

Front 340

Initial Evaluation of the Coughing Dog

Back 340

-Hx:
--exposure to infection (kennel cough, travel)
--Exposure to noxious substances (smoke inhalation)
-Signalment:
--Age
--previous infections
--degenerative disease
--breed predispositions

Front 341

Obesity and Airway Disease

Back 341

-Obesity exacerbates airway disease
-Dogs accumulate fat in neck area, puts additional pressure on the trachea

Front 342

Observation of the Coughing Patient at Rest

Back 342

-Airway disease: patient may be normal at rest
-Pulmonary disease, excluding edema: patient may be abnormal at rest
--increased RR and effort at rest

Front 343

Physical Exam of the Coughing Dog

Back 343

1. Inside mouth:
--pharynx, tonsils, gag reflex
2. Palpation:
--airway, including cervical vertebrae
--Look for compressibility and masses
--Evaluate for cardiac thrill
3. induce cough via tracheal compression
--characterize cough as productive, non-productive, or honking
4. Check for jugular venous distention

Front 344

Coughing Dog Auscultation

Back 344

-Heart: Evidence of cardiac disease?
--murmur or arrhythmia
-Lung fields
--increased bronchovesicular sound
--Crackles
--Wheezes ("squeaks", indicate stenosis and primary bronchiole disease)
-Cervical airway:
--increased upper airway noise at the site of compression

Are noises coming from within the lungs or from the airway and neck?

Front 345

DDx of coughing in dogs

Back 345

-Infectious tracheobronchitis
-Collapsing trachea
-Chronic bronchitis
-Compression of the left mainstream bronchus
-Left-sided congestive heart failure
-Bronchiectasis
-Bronchopneumonia
-Inhaled Foreign Body
-Tracheal or bronchial neoplasia
-Parasites
-Heartworms
-Laryngeal paralysis
-Brachycephalic airway syndrome
-Fungal infections
-Pulmonary inflammatory disorders

Front 346

DDx of coughing in Cats

Back 346

-Feline Asthma (top Ddx)
-Chronic bronchitis
-Bronchiectasis
-Emphysema
-Parasites
-Aspirated foreign bodies
-Bronchopneumonia
-Pulmonary fungal infections
-Pulmonary toxoplasmosis
-Cranial mediastinal masses
-heartworms

Front 347

Cardiogenic causes of Coughing

Back 347

-Congestive heart failure
-Left mainstem bronchus compression by L atrium

Front 348

Airway causes of coughing

Back 348

-Collapsing trachea
-Chronic bronchitis
-Foreign body
-Neoplasia

Front 349

Pulmonary causes of Coughing

Back 349

-Pneumonia
-Pulmonary thromboembolism
-Fibrosis
-Neoplasia
-Other

Front 350

Airway causes of coughing in a Cat

Back 350

-Feline asthma
-Chronic bronchitis

foriegn body and neoplasia are less common

Front 351

Congestive Heart Failure and Coughing

Back 351

-Pulmonary venous congestion
--mitral valve disease
--cardiomyopathy
--arrhythmia
-increased hydrostatic pressure in lungs and lung vessels due to backup from the heart
-Increased hydrostatic pressure leads to increased vascular fluid flux
-Edema occurs when the pulmonary lymphatic system is overwhelmed

Front 352

Dx of left sided congestive Heart Failure

Back 352

-Pulmonary Edema
-Acuscult a murmur and arrhythmia
-Auscultation of moist crackles
-Presence of hypoxia or cyanosis
-Radiographs show cardiomegaly, alveolar disease, and pulmonary venous congestion
--enlarged, tortuous pulmonary vein
-Can do echocardiography

Front 353

Left mainstem Bronchus Compression

Back 353

-Left atrial enlargement causes direct compression of the left mainstem bronchus
-Leads to harsh, dry cough without pulmonary edema

Front 354

Treatment of Coughing due to heart Disease

Back 354

1. Pulmonary edema:
--diuretics
--vasodilators
--inotropes
--anti-arrhythmics
2. Airway compression:
--manage like a collapsing trachea or chronic bronchitis

Front 355

Tracheal collapse

Back 355

-Progressive degenerative disorder of the trachea
-Predominantly in small breed dogs
--mini poodles, yorkies, pomeranians

Front 356

tracheal Collapse Pathology

Back 356

-Cartilage of the tracheal rings is misshapen and softer than normal
-Abnormal cartilage matrix in trachea
-Deficient GAGs
--Decreased number of chondrocytes
-Tracheal dorsal membrane is floppy and stretched
-Variable mucosal inflammation results in edema and mucus accumulation
-more coughing leads to worse inflammation

Front 357

Tracheal Collapse Categorization

Back 357

-Categorized based on location and severity
-Grade 1: 25% obstruction
-Grade 2: 50% obstruction
-Grade 3: 75% obstruction
-Grade 4: 100% obstruction
-Extrathoracic
-Thoracic inlet
-Intrathoracic
-Mainstem bronchus
-Location affects treatment

Front 358

Tracheal Collapse Diagnosis

Back 358

-Clinical signs
-Thoracic and cervical radiographs
-Fluoroscopy
-trachealbronchoscopy

Front 359

Chronic bronchitis

Back 359

-Chronic inflammation of the airways caused by allergy or idiopathic cause
--allergy: eosinophils
--idiopathic: neutrophils, most common
-Inflammation is focused on the Bronchi
-Common problem and difficult to diagnose
-Inflammation causes:
--increased mucus and cellular infiltrates
--abnormal mucociliary escalator function
--Mucosal edema and hyperemia

Front 360

Diagnostic testing for Chronic bronchitis

Back 360

-Take radiographs to exclude other causes of chronic cough
-Do non-invasive tests first
-Test for heartworm and lungworm parasites
-Bronchoscopy to evaluate for collapse
-Can sample from airway for cytology or culture

Front 361

Bronchiectasis

Back 361

-Dilated airways
-Cylindrical is bad news, decreases mucociliary escalator function
--get accumulation of mucus
-Can be acquired or congenital
-Acquired from sequela of chronic airway inflammation
-Delayed clearance due to poor mucociliary function
-Affected animals are predispised to recurrent infections
--may require intermittent or continuous antibiotic therapy

Front 362

Cor Pulmonale

Back 362

-Right heart enlargement that results in lung pathology
-Chronic long-standing lung disease and inflammation

Front 363

Anti-tussives

Back 363

-Centrally acting opiate derivatives
-Suppress coughing and allow patient to exercise and sleep
-Mild sedation can also be helpful
-Dosing frequency is adjusted to effect
-Do not use anti-tussives with a productive cough, want animal to get stuff up and out!
-Anti-tussive agents:
--hydrocodone
--butorphanol
--dextromethorphan

Front 364

Bronchodilators

Back 364

-Have variable efficacy
-Good idea in general, improves oxygenation
--may not change frequency of the cough or life expectancy
-Give it a try, and if ti does not work discontinue
-Methylxanthines (aminophylline)
-B2 agonists cause bronchodilation (terbutaline, albuterol)

Front 365

Corticosteroids in treatment of coughing

Back 365

-Anti-inflammatory doses can be beneficial during acute crisis
-decrease airway inflammation and mucus accumulation
-Doses should be minimized and used to effect
-Prednisone
-Not a cure, manages disease on a long-term basis

Front 366

Aerosolized drugs for Dogs with airway disease

Back 366

-Not always needed if oral drugs are well-tolerated
-Delivers drug directly to site of disease
-Little systemic absorption of the drug
-May have insufficient delivery of the drug to most severely affected areas
-May be more labor intensive
-May be more expensive

Front 367

Inhaled Drugs in animals with Airway Disease

Back 367

-Albuterol: can be used intermittently as part of emergency management
--B agonist
-Fluticasone: must be given consistently for several days before can see effect
--less useful for crisis management
--Steroid

Good for diabetic animals with chornic bronchitits or a dog with combination of chronic bronchitis and heart disease

Front 368

Coughing due to tracheal collapse, chronic bronchitis, and mainstem bronchus compression

Back 368

-Use combination of anti-tussives, bronchodilators, and corticosteroids
--different combination in every dog
-Decrease body weight
-Minimize inhaled stresses
-Minimize exercise and excitement
-Use harness instead of a collar
-Manage concurrent diseases