Pathology Exam 2

Front 1

heart failure

Back 1

- results from inadequate mvmt of blood
- can occur from many different primary causes
- usual end results are pooling of blood in lungs (L heart failure) or liver (R heart failure)
- increased liver enzymes
- long-term failure of one side eventually leads to failure of both (b/c closed system)
- common to see changes in both lungand liver in fatal cases of heart failure
- in L heart failure backs up into lungs b/c can't move blood forward into general circulation

Front 2

patent ductus arteriosus

Back 2

- common in all species- more in dog
- small defects are compatible with life
- large ones results in L -> R shunting of blood
- volume overload of L ventricle and pressure overload of R ventricle (pushing against pressure of patent da)
- connects aorta on L to pulmonary output on R

Front 3

interventricular septal defect

Back 3

- among most common of cardiac defects in animals
- usually a single defect, but can be multiple and in combo with other defects (lives longer with other defects)
- usual site is up under the valves of the great vessels (can miss if don't look close enough)
- in sheep, low under the septum
- defect leads to hypertrophy of L and R ventricles (pressure becomes equal)
- may accomodate this for awhile, then decompensate

Front 4

aortic (rare) and subaortic stenosis (common)

Back 4

- swine, dogs
- present as a fibrous band beneath the aortic valve- can be missed unless specifically looked for
- hard to move blood thru aorta b/c of band
- aorta is usually dilated with ventricle having concentric hypertrophy
- sudden death, due to ventricular fibrillation- usual outcome

Front 5

persistent R 4th aortic arch

Back 5

- most common vascular ring anomaly
- entraps the esophagus, solid food cannot easily pass by the constriction
- result is an esophageal dilation soon after the animal begins eating solid food (after milk)
- secondary aspiration pneumonia is common
- most common in dogs

Front 6

hydropericardium

Back 6

- excess fluid in the pericardial sac
- few milliters are normal, but fluid is usually clear and pale yellow
- common in diseases that cause edema or ascites
- common in R heart failure

Front 7

hemopericardium

Back 7

- accumulation of blood in the pericardial sac
- usually secondary to aortic rupture in horses, rupture of atrial hemangiosarcoma in dogs, more rarely in other diseases
- can result in cardiac tamponage- too much fluid in heart sac, resulting in too much pressure for the myocardium to have a complete excursion
- end results is acute heart failure from heart's inability to move blood

Front 8

fibrinous pericarditis

Back 8

- inflammatory reaction
- fibrin clots in the pericardial fliud
- common in toxemias
- esp common in clostridial toxemias- little evidence of inflammation other than the fibrin
- can look at pericardial fat for BCS

Front 9

hematogenous infections
(fibrinous pericarditis)

Back 9

- in hematogenous infections of the pericardial space the fibrin is more abundant, adherent to the pericardial surfaces, and contains numerous neutrophils ("fibrinsuppurative")
- less contaminated than when due to penetrating FB
- pristine exudate

Front 10

traumatic reticulopericarditis/ hardware disease
(fibrinous pericarditis)

Back 10

- exudate is usually discolored and can be foul smelling

Front 11

mineralization of endocardium

Back 11

- rare
- endocardium is a prime site for metastatic mineralization due to prolonged hypercalcemia
- vitamin d toxicosis is a rule-out (in herbs can include plant toxins that are vitamin d analogs)

Front 12

endocardiosis

Back 12

- degernative lesion (noninflammatory)
- generally on AV valves
- valves are thickened, but smooth and glistening
- can be incidental findings, esp in older dogs
- can also lead to valvular incompetence adn heart failure
- one common cause of murmurs in older dogs

Front 13

endocarditis

Back 13

- bacterial, valvular, inflammatory, rough, opaque
- valve most likely, tho in cattle tricuspid more common
- req 2 things: turbulent flow & bacteremia
- in most occur sporadically & unlikely to be concurrent
- chronic septic conds, bacteremia held constant, waiting for turbulent flow to damage a valve
- heart defects- turbulent flow held constant, waiting for sporadic bacteremia
- common to also have chronic sepsis or heart defect
- if 1 of 2 held constant, other 1 comes along eventually
- mural endocarditis- cardiac wall instead of valves (rare)

Front 14

mineralization of myocardium

Back 14

- nearly always dystrophic (in contrast to the metastatic mineralization of the endocardium)
- usually related to necrosis of myocytes
- nutritional cardiomyopathy from selenium deficiency is a rule-out

Front 15

hypertrophy

Back 15

- an increase in cell size but not in cell number
- compensatory change in response to an increase in either systolic or diastolic work load
- physiologic is reversible
- pathological is not reversible

Front 16

concentric hypertrophy

Back 16

an increase in ventricular mass without an increase in end diastolic volume
- usually associated with increased systolic load (aortic or pulmonic stenosis, PDA)
- wall is thick, but ventricular lumen unchanged

Front 17

eccentric hypertrophy

Back 17

- increase in myocardial mass with an increase in end diastolic volume
- usually secondary to volume overload
- usually seen with incompetent AV valves, incompetent semilunar valves, or av shunts
- wall may be no thicker than normal
- increase in size due to the increase in volume related to ventricular lumen dilation

Front 18

myocarditis

Back 18

- inflammation of the heart muscle
- usually bacterial
- usually secondary to vegetative valvular endocarditis of the mitral or aortic valve, with septic emboli lodging along the coronary arteries
- animal usually has significant inflammation in locations other than the heart
- usual lesion is multifocal pale regions in the myocardium that extend deep into it
- extent of lesion can be very great or very minor
- very minor lesions can be rapidly fatal if they involve the conduction system or induce ventricular fibrillation

Front 19

cardiomyopathy

Back 19

- dysfunction of the myocardium
- usually of unknown cause
- almost always with morphologic changes
- 3 general forms: dilative (large ventricular lumens), hypertrophic (thickened ventricular walls), restrictive (thickened walls with a diminished ventricular lumen)
- difference btw hypertrophic and restrictive is likely one of degree rather than general type
- hypertrophic usually precedes restrictive

Front 20

cardiomyopathy in dogs

Back 20

- dilative form is most common
- usually in large breeds as a familial defect
- hypertrophic cardiomyopathy is less common

Front 21

cardiomyopathy in cats

Back 21

- dilative is called congestive
- usually related to taurine deficiency (rare now that this relationship has been recognized)
- common for dilated heart to have atrial thrombi and thromboemboli going down the aorta to lodge at the iliac bifurcation
- taurine supplementation can reverse early cases

Front 22

hypertrophic cardiomyopathy in cats

Back 22

- relatively common
- genetic in a few breeds
- heart wall is thick
- left ventricular lumen compromised
- R sided, L sided, or both sided heart failure ensues
- many cats with this show signs of heart failure, other have sudden death (may be due to ventricular fibrillation)

Front 23

neoplasia of heart

Back 23

- rare in the heart

Front 24

- "heart base tumors"

Back 24

- include aortic body, ectopic thyroid or parathyroid masses

Front 25

hemangiosarcoma of heart

Back 25

- relatively common as a primary lesion in the R atrium of dogs
- presentation can be death from rupture and hemorrhage into the pericardial sac with secondary cardiac tamponade

Front 26

rhabdomyomas and neurofibromas of heart

Back 26

- rare
- usually round
- have distinct color changes from normal myocardium

Front 27

ateriosclerosis

Back 27

- "hardening of the arteries"
- other lesions: proliferative and degenerative changes in the media of the walls (rarely clinically significant)
- common in humans, rare in animals
- most common in rabbits, pigs, chickens (latter 2 rarely survive long enough to develop the lesion)
- dogs occasionally affected

Front 28

atherosclerosis

Back 28

- "mushy arteries"
- buildup of cholesterol-containing plaque on the internal surface of arteries
- common in humans, rare in animals
- most common in rabbits, pigs, chickens (latter 2 rarely survive long enough to develop the lesion)
- dogs occasionally affected

Front 29

arterial medial calcification

Back 29

- occurs in elastic and large artieres as a consequence of vitamin d toxicosis (usual), renal failure (rare), or severe cachexis such as Johne's disease

Front 30

hypertrophy of pulmonary arteries in cats

Back 30

- relatively common, esp in cases of lungworms or dirofilariasis
- also idiopathic change
- can occur in other species as resposne to pulmonary hypertension, or as response to hypoxis such as in high-altitude disease
- can result in R-sided heart failure

Front 31

thrombosis, embolism

Back 31

- any hypercoagulable state can lead to fibrin formation in the arterial system, and subsequent thrombosis
- nephrotic syndrom can result in loss of antithrombin III (common)
- hyperadrenalcorticism- underlying cause
- any endothelial damage can favor thrombosis as the protective function of normal endothelium is lost
- emboli can include: fat (post traumatic), air (secondary to pneumocystography, rare), parasitic (esp if parasites are killed by therapy)

Front 32

arteritis, angitis, vasculitis

Back 32

- used interchangeably
- host of infectious agents can cause this
- several viruses cause arteritis as their main mechnism of action
- consequences of arteritis are damage to wall, enhanced portential for aneurysm or thrombosis or both
- septic emboli from R sided vegetative valvular endocarditis of cattle can cause aneurysms of pulmonary arteries with dramatic and fatal rupture into large airways

Front 33

porto-systemic shutn in dogs

Back 33

- shunts connect portal to the systemic vasculature
- results in blood from intestinal tract bypassing the liver
- consequences related to buildup of metabolites that havae not been biotransformed by normal liver function

Front 34

phlebitis

Back 34

- inflammation of veins
- usually phlebitis and thrombosis occur concurrently
- either one can lead to the other
- hypercoagulable states can lead to spontaneous thrombosis (nephrotic syndrome leading to renal vein thrombosis)
- omphalophlebitis (navel ill)- one of more common of phlebitides, related to bacterial contamination of the umibilical stump at birth

Front 35

lymphangiectasis

Back 35

- dilation of lymphatics
- usually second to obstruction
- most common cases are either granulomatous inflammation or neoplasia
- most common in the intestinal mucosa- leads to protein-losing enteropathy
- diseases leading tho this are Johne's disease (rums) and chornic inflammatory bowel disease (dogs), Chrohn's disease (humans)

Front 36

chylothorax

Back 36

- accumation of lymph in the thorax
- usually from rupture of the thoracic duct
- more common in cats than other species
- usually the rupture is difficult to document

Front 37

hemangioma of vasculature

Back 37

- benign masses of vascular origin
- usually formed of large, well-differentiated blood-filled spaces
- usually dermal in dogs
- lymphangiomas are rare- similar except for lacking blood in the spaces

Front 38

hemangiopericytomas of vasculature

Back 38

- common neoplasms in dogs
- usually in skin, subcutis, or superficial tissues
- come from hemagiopericytes
- typical soft-tissue sarcomas of dogs- usually infilatrative but slow to metastasize
- commonly recur after (incomplete) removal
- regrowths are usually more aggressive than the original mass

Front 39

hemangiosarcomas of vasculature

Back 39

- malignancies of blood vessels
- usually masses of small, bizarre blood-filled channels
- tend to be primary in spleen, liver, or R atrium of heart
- can metastasize to liver, lung, or skin
- clinical consequences for the splenic and cardiac masses include rupture and fatal hemorhage

Front 40

cleft palate

Back 40

- any length
- can be partial or complete
- secondary rhinitis and aspiration pneumonia may occur in severe cases
- trouble suckling

Front 41

choanal atresia

Back 41

- narrowing or close of the ventral meatus of the nasal cavity
- occurs most often in llamas
- may be mouth breathers

Front 42

brachycephalic airway sydrome

Back 42

- respiratory impairment caused by an excessive length of the small palate
- stenotic (narrow) external nostrils in brachycephalic breeds of dogs
- can lead to cyanosis
- airway is obstructed

Front 43

epistaxis

Back 43

- nose bleed
- seen in association with many hemorrhagic diatheses (thrombocytopenia, DIC, ehrlichia)
- trauma to the nasal cavity
- guttural pouch inflammation
- from the lung when a blood vessel ruptures: occurs in cattle with rumenitis and secondary fungal or bacterial infection of the rumen that spreads to the liver forming an abscess -> abscess erodes thru a blood vessel causing epistaxis -> goes to the lung -> will come up thru nose
- neoplasia in the nasal cavity

Front 44

laryngeal edema and hemorrhage

Back 44

- freq occurs terminally when n animal dies with respiratory distress
- occurs in shock in some speices- equine
- secondary to intubation

Front 45

rhinitis

Back 45

- often part of generalized infection
- usually acute with hyperemia, edema and a catarrhal or mucopurulent exudate (thick, white)
- hemorrhage, necrosis and ulceration may also occur depending on severity of disease
- may form fibrin
- more severe = both nasal passages affected
- causes for cattle- IBR, BVD, malignant catarrhal fever
- causes for feline- feline herpes virus
- causes for canine- distemper
- causes for equine- rhinopenumonitis (herpes virus), influenza

Front 46

atrophic rhinitis

Back 46

- important cause of economic loss in young swine
- complete pathogenesis is uncertain- toxigenic strains of bordetella bronchiseptica and pasteurella multocida are likely causes of disease
- bacteria act in association with certain enhancing factors such as nutritional imbalances or adverse environmental factors that favor colonization by the bactera
- toxin affects osteoblast function leading to osteopenia and atrophy of turbinate bone

Front 47

localized rhinitis- allergic rhinitis

Back 47

- uncommon dz occuring mostly in cattle and occ in dogs and cats
prod a mucopurulent exudate with many eosinophils

Front 48

localized rhinitis- fungal

Back 48

- produce granulomatous inflammation and a solid mass in the nasal cavity
- must be differentiated from nasal carcinoma
- aspergillus in dogs and cats produces a necrotic exudate
- cryptococcus produces a mucoid exudate in cats

Front 49

localized rhinitis- strangles

Back 49

- purulent rhinitis and lymphadenitis of horses caused by Streptococcus equi

Front 50

polyps

Back 50

- nasal polyp occurs occ in horses- usually as single nodular or sessile mass

Front 51

polyps- ehtmoid hematoma

Back 51

- occurs occ in ethmoid region of nasal cavity of horse
- chronic bleeding mass with much scarring and causes obstruction

Front 52

polyps- nasopharyngeal polyp

Back 52

- cats
- polyp arising in the Eustachian tube or middle ear

Front 53

sinusitis

Back 53

- often an extension of rhinitis- similar pathological features
- nasal bots (oestrus ovis) of sheep are a common cause of sinusitis and rhinitis in animals

Front 54

maxillary sinusitis

Back 54

- horses
- occurs secondary to an infected molar tooth

Front 55

infraorbital sinusitis and tracheitis

Back 55

- infectious coryza of avian species
- caused by hemophilus gallinarum

Front 56

necrotic laryngitis

Back 56

- calf diphtheria
- common dz of calves
- caused by fusobacterium necrophorum
- mucosa is necrotic and ulcerated
- debris forms a dry, ywllo, caseous mass covering the larynx

Front 57

infection of guttural pouches

Back 57

- infection by fungi or bacteria is uncommon
- fungal infs produce a fibrinonecrotic inflammation
- bacteria infs produce a purulent inflammation
- proximity of pouches to internal carotid artery can lead to rupture with epistaxis or involvement of adjacent bone and cranial nerves that pass thru the area
- pouch may fill with pus- called empyema

Front 58

laryngeal hemiplegia

Back 58

- atrophy
- important in racing horses
- leads to inspiratory distress often producing a roaring noise
- one side if paralyzed, so smaller than other side
- dmage to recurrent laryngeal nerve results in damage from tumors, guttural pouch infection, compression, etc

Front 59

neoplasms of nasal cavity

Back 59

occur most commonly in the dog, cat, horse

Front 60

carcinoma of nasal cavity

Back 60

occurs in the dog

Front 61

squamous cell carcinoma of nasal cavity

Back 61

-cat- nasal planum
- horse- maxillary sinus

Front 62

ethmoidal neoplasms

Back 62

- arise from the olfactory epithelium
- caused by a retrovirus
- can be adenoma or carcinoma
- most common in sheep in US (endemic in certain areas)

Front 63

laryngeal neoplasia

Back 63

rare

Front 64

rhabdomyoma

Back 64

occurs in larynx of the dog

Front 65

tracheal collapse

Back 65

- toy and miniature breeds of dogs
- trachea is collapsed dorsoventral causing obstruction and respiratory distress
- usually entire trachea is affected but can be segmental
- can develop at any age

Front 66

hyperemia of trachea

Back 66

- occurs commonly in large animals with respiratory distress prior to death
- hemorrhage and edema may accompany the reaction
- change is usually diffuse, but may occur as linear red streaks
- hyperemia/hemorrhage is a freq finding in inflammatory diseases of the trachea

Front 67

tracheitis, bronchitis, bronchiolitis

Back 67

- freq occur together
- may be associated with inflammation in the lung or nasal cavity
- severity of inflammation depends on the cause

Front 68

catarrhal inflammation (conducting airways)

Back 68

- primarily a mucous exudate without hyperemia
- many different causes
- dog- tracheobronchitis due to adenovirus, bordetella, parainfluenza virus
- avian- infectious bronchitis (corona virus), quail bronchitis (adenovirus)

Front 69

hrmorrhagic, necrotizing (conducting airways)

Back 69

- usually diffuse with hypermia, some edema
- linear or petechial hemorrhages, necrosis
- many causes
- cattle- IBR, malignant catarrhal fever
- avian- laryngotracheitis (herpes virus)- mostly hemorrhagic
- all species- rhinotracheitis

Front 70

parasitic (conducting airways)

Back 70

- several parasites prod nodules in the airways that are not associated with inflammation grossly- rare dzs

Front 71

syngamus trachea

Back 71

- turkeys
- large red worm that is attached to the nodule
- don't block airways
- lots of worms can elicit a cough

Front 72

oslerus osleri

Back 72

- dogs
- parasite embedded in the nodule and not visible grossly
- near tracheal-bronchi region- may cause cough

Front 73

allergic bronchitis

Back 73

- feline asthma and "heaves" in horse (expiratory)
- caused by inhaled allergens in dust, plant materials and others
- airways are plugged with mucus in bronchioli
- SM hypertrophy of airways (circles the airways)

Front 74

chronic bronchitis

Back 74

- may progress to bronchiectasis
- dilation of the bronchi due to partial rupture of the bronchial wall
- exudates in the bronchi that cannot be cleared and proteolytic enzymes relased from inflammatory cells degrade the wall leading to dilation (chronic change- won't go back to normal shape)

Front 75

bronchiolitis

Back 75

- may progress to bronchiolitis obliterans
- exudate in the bronchioles is not removed but is organized into fibrous tissue that plugs the bronchiole
- permanently damaged and nonfunctional lung

Front 76

chondromas- growth disturbance

Back 76

- neoplasis of conducting airways
- very uncommon
- metaplastic lesions of the cartilaginous rings and not true neoplasms
* will never see one*

Front 77

squamous metaplasia of conducting airways

Back 77

- of mucosa
- occurs in birds with vitamin A deficiency
- must less common in mammals

Front 78

edema of the lung

Back 78

- common lesion of the lung produced by many infectious and toxic agents, shock, endotoxemia, and complication of heart failure (most likely cause)
- palpates like rubber
- lungs are heavy and wet and will exude fluid on cut surface
- interlobular septa are widened and transparent
- lung is diffusely congested
- foam is usually present in the trachea- can be postmortem change
- can lead to death
- lungs look rounded, plump, diffuse red, wet on necropsy

Front 79

hemorrhage of lung

Back 79

- occurs with inflammation of the lung (pneumonia), trauma, coagulopathies, sepsis, thromboembolism
- may produce epistaxis
- exercise induced pulmonary hemorrhage occurs in racehorses following exercise
- mottled look, sharp deliniations/edges to redness

Front 80

thrombosis of lung

Back 80

- occurs occ in pulmonary arteries in association with amyloidosis and glomerulonephritis in the dog, DIC, hyperadrenocorticism, or hypercoagulable states
- thromboemboli occure more commonly and are emboli of bacteria or neoplastic cells that form thrombi in the lung
- instant death if blocks lungs

Front 81

infarction of lung

Back 81

- uncommon b/c of the dual blood supply
- do occur as focal, sharply demarcated, firm, red areas
- lung lobe torsion results in infarction
- necrosis of tissue due to thrombus in blood vessel
- can look like pneumonia

Front 82

atelectasis

Back 82

- incomplete distension of the alveoli
- congenital or aquired

Front 83

congenital atelectasis

Back 83

- failure to inflate the lungs at birth
- lungs are diffusely and uniformly dark red and rubbery, do not float
- dark red b/c seeing all blood vessels with no air in them, so closer together

Front 84

aquired atelectasis

Back 84

- lungs have red, slithly depressed areas that are sharply demarcated
- areas are differentiated from penumonia b/c rubbery and not consolidated like pneumonia

Front 85

aquired atelectasis- bronchilal or bronchiolar obstruction

Back 85

- most important cuase
- complete obstruction preventing filling of the alveoli, coupled with poor collateral ventilation leads to atelectasis
- lobules are highly susceptible to the development of bronchopneumonia

Front 86

aquired atelectasis- compression from a lung mass

Back 86

- could also be pleural effusion or pleural mass

Front 87

aquired atelectasis- recumbenant with shallow breathing

Back 87

- prone to develop atelectasis

Front 88

interstitial emphysema

Back 88

- excess air in the interlobular septs
- most common in the bovine
- slight amt of interstitial emphysema is considered a normal post mortem finding in that species

Front 89

alveolar emphysema

Back 89

- excess air in the alveoli
- results from an inflammatory process in the alveolus that weakens the wall allowing expansion (rare in animals)
- can also occur secondary to bronchiolar obstruction where air is inspired and trapped in the lung

Front 90

chronic obstructive pulmonary disease

Back 90

- alveolar emphysema in horses
- called "heaves"
- chronic bronchiolitis associated with alveolar emphysema in many cases
- an allergic rxn to inhaled allergens is the probable cause
- bronchioles have goblet cell metaplasia and obstruction of the airway by mucus

Front 91

torsion of a lung lobe

Back 91

- occurs occasionally in dogs
- occlusionof the blood supply leads to rapid infarction of the lob
- accessory lob is most commonly involved

Front 92

pneumonia

Back 92

- most important disease of the respiratory system of animals
- causes include bacterial, viral, parasitic, toxic, and immune-mediated (pathology is variable)
- 2 groups: bronchopneumonia and interstitial pneumonia
- easiest to classify pneumonias based on gross pathologic appearance
- 3 groupings based on distribution of gross lesions: diffuse distribution, locally extensive distribution, focal, multifocal distribution

Front 93

bronchopneumonia

Back 93

- the primary lesion is a broncholitis of the terminal bronchiole

Front 94

interstitial pneumonia

Back 94

- the primary lesion is inflammation of the alveolar septa or interstitium

Front 95

aspiration/inhalation pneumonia

Back 95

- inhalation of fluid or drenches produces a necrotizing almost grangrenous penumonia that often has a very fetid odor
- location of thelesion depends on the type of material aspirated and the body position of the animal at the time of aspiration
- usually only one area of lung is affected which distinguishes this pneumonia from bronchopneumonia

Front 96

focal/multifocal distribution- pneumonia

Back 96

- lung has scattered individual or many small, single, discrete foci throughout
- intersititial pneumonias b/c the reaction centers on the interstitium
- different grossly from interstitial pneumonias of diffuse distribution

Front 97

metastatic (embolic) pneumonia

Back 97

- focal/multifocal distribution
- results from bacterial showering (embolism) of the lung during bacteremia
- lung is dotted with raised, red, white, or yellow foci that often contain pus

Front 98

granulomatous pneumonia

Back 98

- focal/multifocal distribution
- chronic intersitial pneumonias
- characterized by firm raised lesions that are ywllo, white, gray
- common causes include deep mycoses (blastomyces, coccidioides, histoplasma), phenomoconiosis (silica, asbestos, coal), tuberculosis, asperigillosis in birds, cryptococcus, rodococcus equi in foals

Front 99

allergic pneumonitis

Back 99

- focal/multifocal distribution
- produced by a variety of inhaled antigens usually in dust
- molds are the most common cause and Saccharopolyspora faeni in cattle is the most studied (farmer's lung in man)
- horses and cattle are most commonly affected
- usually chronic

Front 100

verminous pneumonia

Back 100

- focal/multifocal diffusion
- dictyocaulus in ruminants produces a locally extensive penumonia in the dorsal regions of the caudal lobes
- muellerius in sheep/goats produces a multifocal interstitial pneumonia characterized by raised, gray-green nodules located just beneath the pleura in the caudal lobes
- lungworms occur infrequently in other species where they produce a multifocal pattern of small nodules or plaques

Front 101

primary lung tumors

Back 101

- uncommon in all species (most seen in dog)
- carcinomas of various types comprise 80% of neoplasms (single or multiple distinct masses in periphery of lung)
- malignant neoplasms- metastasize within the lung and to local lymph nodes and other organs

Front 102

pulmonary adenomatosis

Back 102

- primary lung tumor
- carcinoma in sheep lung occurring in many places but not the US
- caused by a retrovirus
- produces a multifocal pattern of firm, gray-white plaques throughout the lung

Front 103

metastatic tumors

Back 103

- b/c of blood supply, lung is most common site for metastatic tumors to occur
- both carcinomas and sarcomes of various types metastatize to the lung (multifocal distribution)
- metastatic lung neoplasia must be differentiated from primary lung neoplasia and certain multifocal pneumonias (absence of a primary tumor elsewhere would rule out metastatic neoplasia)
- histology is the final definitive diagnosis

Front 104

hydrothorax

Back 104

- may occur in congestive heart failure, pulmonary edema, pleuritis, neoplasia of the pleura
- presence is not a consistent feature
- may also occur in other conditions where it is often unexplained

Front 105

chylothorax

Back 105

- chylous effusion is an effusion of lymph fluid rich in triglycerides
- occurs with rupture of the thoracic duct (rare), neoplasia or inflammation in the thorax, idiopathic
- most common in cats due to cardiomyopathy

Front 106

hemothorax

Back 106

- blood in the thorax
- occurs with rupture of a blood vessel, coagulopathies, DIC
- blood in multiple places might be bleeding disorder

Front 107

pneumothorax

Back 107

- results when air escapes from the lung, or enters thru the diaphragm, or a penetrating wound in the thorax

Front 108

pyothorax

Back 108

- excess accumulation of pus in the pleural cavity as a result of pleuritis
- most commonly seen in cats, dogs, horses
- penetrating plant awns are a common cause in dogs and cats in certain geographical locations

Front 109

pleuritis

Back 109

- inflammation
- usually acute and often produces an effusion (hydrothorax, pyothorax)
- resolution is usually by formation of fibrous adhesions btw the lung and thoracic wall

Front 110

primary pleuritis

Back 110

- component of polyserositis where peritoneum, pleura, and pericardium are involved
- usually produce a serous effusion
- causes include Hemophilus parasuis, Mycoplasma hyorhinis- both in pigs
- penetrating wound of the thorax

Front 111

secondary pleuritis

Back 111

- occurs most often secondary to pneumonia- called pleuropneumonia
- severe cases of bacteria bronchopneumonia and Mycoplasma mycoides in cattle, sheep/goats all produce pleuropneumonia
- often pneumonia has resolved or is focal in distribution so its presence is not apparent grossly (these cases are not primary pleuritis)

Front 112

mesothelioma

Back 112

- rare neoplasm in animals seen most commonly on peritoneum in calves (born with it)
- can occur in any body cavity
- in dog (as in man) this has been associated with the presence of asbestos fibers
- most common cause of pleuritis

Front 113

metastatic neoplasia

Back 113

- carcinomas often implant on the pleura

Front 114

amelia

Back 114

- absence of a limb

Front 115

syndactyly

Back 115

- fusion of digits

Front 116

polydactyly

Back 116

- multiple digits

Front 117

arthrogryposis

Back 117

- permanent flexure of limbs (locked joints)
- "crooked calves" results from ingestion of lupines at 40-70 days gestation
- bluetonue virus, manganese deficiency, genetic causes also produce this
- also have swollen brains, large heads

Front 118

kyphosis

Back 118

- dorsal curvature of spine

Front 119

lordosis

Back 119

- ventral curvature of spine

Front 120

scoliosis

Back 120

- lateral curvature of spine

Front 121

spina bifida

Back 121

- failure of the neural arch to close leaving an exposed spinal cord or meninges

Front 122

hemivertebra

Back 122

- a failure of fusion in the fetal spine producing a small vertebra

Front 123

periosteal hyperostosis (osteodystrophy)

Back 123

- proliferation of periosteal new bone on long bones
- inherited disease of pigs- animals are stillborn

Front 124

osteogenesis imperfecta (osteodystrophy)

Back 124

- rare inherited disease of cattle
- defective osteoid formation
- cortex of bones is thin and trabeculae are decreased in number

Front 125

osteopetrosis (osteodystrophy)

Back 125

- increase in the thickness of a bone due to an inherited osteoclast defect
- bone is thick with no medullary cavity but the bone is brittle and prone to fracture
- lambs and calves are affected and are usually stillborn

Front 126

circulatory disturbances- hemorrhage

Back 126

- occurs when bone is damaged by any cause such as fracture, osteomyelitis, neoplasia

Front 127

circulatory disturbances- ischemia

Back 127

- occurs commonly in bone following fractures, neoplasia, or inflammation adn leads to necrosis
- aseptic necrosis of the femoral head occurs occaisonally in young miniature breeds of dogs (leads to collapse of femoral head)
- cause of ischemia is unknown

Front 128

hypertrophic osteopathy

Back 128

- periosteal proliferation of bone along the diaphysis of limb bones (symmetrical)
- rare disease occurring mostly in the dog
- occurs secondary to neoplasia, inflammation or occ other space occupying disease of the lung (may also occur with lesions of the heart, abdomen, or urinary bladder)
- primary mass stimulates increased vascular perfusion to the periosteum by an unknown mechanism
- may be mediated thru the vagus nerve, as vagotomy will often cause regression of the bone formation

Front 129

tibial dyschondroplasia in birds

Back 129

- similar to osteochondrosis of mammals
- affects young domestic poultry
- has been reported in exotic birds
- anterior tibia has anterolateral bowing due to a mass of retained cartilage in the metaphysis
- cause is unknown but dietary and genetic factors are probably involved

Front 130

nutritional osteoporosis

Back 130

- most common type of osteoporosis
- causes: starvation, protein deficiency, deficiencies in copper/manganese/zinc

Front 131

disuse osteoporosis

Back 131

- occurs secondary to prolonged muscular inactivity or reduced weight bearing such as in fracture immbilization

Front 132

senile osteoporosis

Back 132

- normal physiologic process of aging in man
- more common in females
- occurs in longer-lived animals but rarely associated with clinical signs

Front 133

corticosteroid-induced osteoporosis

Back 133

- rarely produces clinical signs
- cause is uncertain but may infolve the effect of steroids on suppression of protein synthesis and other cellular energy metabolism

Front 134

hypervitaminosis A in cats

Back 134

- disease of older cats fed high levels of vitamin A
- all liver diets are usual cause- animal must be on diet 1-5 years before clinical signs appear
- lesion is a multiple exostoses occurring mainly in cervical vertebrae (also on sternebrae, joints of long bones)
- osteopenia of bones also occurs
- pathogenesis is uncertain
- vitamin A is toxic to chondrocytes, death of cells leads to endochondrial ossification and formation of exostoses

Front 135

avian perosis

Back 135

- disease of young growing poultry and game birds
- swollen, enlarged hocks and twisting deformities of the distal tibia and proximal metatarsus
- gastrocnemius tendon slips out of the condyle
- birds cannot walk and die from lack of food and water
- deficiencies of choline, manganese, folic acid, panothenic acid, biotin and niacin can all produce this

Front 136

panosteitis

Back 136

- a self-limiting disease of young, large/giant breed dogs affecting the long bones
- males are affected 4:1 over females and most dogs are under 1 yr of age
- cause is unknown
- lesions regress in several months
- endosteal new bone formation in the diaphysis is the main lesion often filling the medullary cavity
- some periosteal new bone formation is present
- no inflammation

Front 137

simple/closed fracture

Back 137

- skin is not broken

Front 138

compound/open fracture

Back 138

- skin is broken

Front 139

pathologic fracture

Back 139

- a fracture occurring secondary to a bone disease like neoplasia, osteomyelitis, or nutritional bone disease

Front 140

comminuted fracture

Back 140

- multiple small fragments of bone

Front 141

greenstick fracture

Back 141

- one side of the bone is broken while the other side is bent without separation fo the boen

Front 142

transverse/oblique/spiral fractures

Back 142

- designate the orientation of the fracture line

Front 143

osteoma

Back 143

- rare, benign tumor of cattle and horses occurring in the bones of the head
- tumros can be 15cm or greater in size
- b/c of their location usually cause problems with respiration or mastication
- composed of trabecular bone covered by a fibrous capsule
- two variants of this tumor also occur called ossifying fibroma and fibrous dysplasia

Front 144

chondroma

Back 144

- rare, benign tumor occurring on the flat bones in sheep, dogs, cats
- used to designate reactive cartilagenous growths occurring in arthritis
- tumors consist of mature hyaline cartilage

Front 145

multilobular tumor

Back 145

- tumor occurs in the bones of the skull of the dog
- most common benign tumor of bone
- consists of lobules of cartilage or bone separated by fibrous tissue to form a multilobular pattern radiographically and histologically
- slow growing
- progressively malignant with metastasis occurring late in the disease
- can cause compression of the brain or expansion into the orbit or sunuses making resection difficult
- recurrence rate is high

Front 146

chondrosarcoma

Back 146

- 2nd most common bone tumor of the dog accounting for 15% of bone tumors
- affects large but nto fiant breeds of dogs
- occurs in cats and sheep
- arises within flat bones and the nasal cavity but can occur in long bones
- slower growing than osteosarcoma causing less deestruction of bone with less lysis and more proliferation of bone
- will cross the joint space
- slower to metastasize then osetosarcoma
- has a mean survival of 1.5yrs in dog

Front 147

fibrosarcoma & hemangiosarcoma

Back 147

- occurs in long bones of dogs
- must be differentiated from osteosarcoma
- intermediate btw osteosarcoma and chondrosarcoma in their behaviro

Front 148

metastatic neoplasia (bone)

Back 148

- occasional carcinomas will metastasize to bone
- prostatic and urinary bladder tumors are most likely to do this, but other tumors rarely do so
- typically produce lytic lesions in multiple bones (vertebra)

Front 149

strain

Back 149

- mild stretching of joint capsule

Front 150

sprain

Back 150

- stretching of joint capsule and associated ligaments without displacement of the joint surfaces
- ligaments may tear

Front 151

subluxation

Back 151

- incomplete separation of joint surfaces
- partial tearing of capsule often occurs

Front 152

luxation

Back 152

- complete separation of joint surfaces
- joint capsule is completely torn

Front 153

ringbone

Back 153

- degenerative joint diseaes of hte interphalangeal joints of the forelimbs of horses
- characterized by excessive osteophyte production forming a ring around the end of the bone

Front 154

spavin

Back 154

- degenerative arthropathy of the tarsus in hroses and sometimes cattle

Front 155

navicular disease

Back 155

- degenerative arthropathy of the navicular bone affecting the forelimbs of hroses
- abnormal foot conformation predisposes to this disease

Front 156

spondylosis

Back 156

- development of osteophytes on the ventral and lateral aspects of adjacent spinal vertebra
- often incidental findings related to aging in dogs but may be more extensive adn produce clinical signs in animals with increased physical activity, wt bearing, or herniated intervertebral disks
- bony bridging of the ventral vertebral bodies may occur

Front 157

discospondylitis

Back 157

- infectious disease of the intervertebral disks of large dogs that appears similar grossly to spondylosis
- affects the disks and endplates of the vertebra
- usually caused by Brucella or Staphylococcus bacteria

Front 158

intervertebral disk disease

Back 158

- chondrodystrophic breeds of dogs is a degenerative arthropahy of the intervertebral disk
- gelatinous disk undergoes premature degeneration with formation of cartilage and mineralization
- annulus fibrosis that surrounds the nucleus pulposus also degenerates
- chagnes lead to decreased flexibility of the disk predisposing to herniation or rupture

Front 159

systemic lupus erythematosus (nonerosive arthritis)

Back 159

- a chronic, immune mediated disease in whic circulating immune complexes are deposited in joints
- Ab is directed against nuclear antigens and called antinuclear antibody (ANA)
- hemolytic anemia, renal disease and vesicular dermatitis are other manifestations of this disease
- arthritis causes less cartilage damage than rheumatoid arthritis
- often nonerosive

Front 160

synovial sarcoma

Back 160

- only important neoplasm of joints
- arises from the synovial lining cells
- most often seen in the large joints of the limbs of dogs
- also occurs in the soft tissue and tendons around joints where synovium encloses tendon sheaths and bursa
- tumor is very destructive of the joint and adjacent bone
- amputation is the recommended treatment
- local recurrence is common but metastasis is slow and occurs in 25% of cases

Front 161

dystrophy

Back 161

- muscular dystrophy is a group of rare, inherited sieases affecting most animal species
- msucles are pale and atrophic due to progressive degeneration, necrosis and loss of myofibers with replacement by fat and fibrous tissue

Front 162

myotonia

Back 162

- group of rare mostly inherited diseases of animals characterized by prolonged contraction of muscles
- contractions can be stimulated manually or by startling the animal
- muscles contract for several seconds and produce a dimpling of the skin
- muscle may be enlarged and prominent grossly
- most common in goats

Front 163

spastic paresis

Back 163

- inherited disease of cattle in which the rear limbs are straight at the hock and unable to flex

Front 164

myasthenia gravis

Back 164

- rare disease of dogs characterized by muscle weakness and fatigue
- dogs are normal at rest but become weak shortly after beginning to exercise
- some are congenital due to an inherited deficiency in the numbers of acetylocholine receptors in muscle
- msot cases are acquired, occur in adult dog and are caused by antibodies against the acetylcholine receptors
- muscles are normal grossly and microscopically

Front 165

polysaccharide storage myopathy of the horse

Back 165

- inherited disease of horses and ponies thought to be a defect in carb metabolism
- muscles may have necrosis or atrophy
- aggregates of abnormal carb called amylopectin are present microscopially in muscle fibers

Front 166

hyperkalemic periodic paralysis of horses

Back 166

- inherited defect in sodium channels within muscle fibers that results in hyperkalemia
- horses have transient muscle spasm followed by flaccid paralyssi
- episodes occur periodically and horses may have long periods of being normal
- no gross or microscopic lesions are seen in the muscle

Front 167

denervation atrophy

Back 167

- common disease of muscle caused by damage ot the nerve supply from trauma, inflammation, neoplasia, other causes
- atrophy occurs quickly within a few weeks and affect both type 1 and type 2 myofibers

Front 168

disuse atrophy

Back 168

- occurs whenm muscles are not used such as limbs that are casted or painful
- atrophy is nto as marked as that of denervation and occurs more slowly

Front 169

cachnexia of disease or malnutrition

Back 169

- both results in protein mobilization from muscle to supply energy

Front 170

endocrine atrophy

Back 170

- occurs in hyperadrenocorticism and hypothyroidism occasionally
- presents as generalized weakness
- atrophy is not visible grossly but is present microscopically

Front 171

hypertrophy

Back 171

- occurs in resposne to increased workload such as racing animasl
- hypertrophy of myofibers occurs microscopically as a compensatory response when muscle is damaged and is seen in many muscle diseases

Front 172

vitamin E/selenium deficiency

Back 172

- causes nutritional myopathy of young ruminants
- affected animals have a stiff gait and those with cardiac necrosis may become recumbent and die with respiratory failure
- rear limb muscles are usually affected and the lesions are bilateral adn symmetrical
- other muscles may be affected such as the diaphragm and in suckling animals the tongue and neck muscles
- disease is called white muscle disease b/c the muscles typically have white streaks

Front 173

monensin

Back 173

- coccidostatic drug for poultry
- used as a growth promoter in ruminant feed
- it is toxic for monogastric animals, particularly horses, which accidentally consume the feed
- toxic for ruminants if fed in excessive amounts- toxicities are usually due to feed mixing errors
- early lesions have pallor of the muscle and the white streaking develops later

Front 174

cassia occidentalis (coffee senna)

Back 174

- poisonous plant in the souther US causing skeletal muscle necrosis in ruminants consuming the plant after a killing frost
- animals have a stumbling gait, weakness, diarrhea
- some become recumbent and develop myoglobinuria and cardiac necrosis
- muscle is usually pale with minimal white streaking

Front 175

adriamycin

Back 175

- an anticancer drug in small animals
- will cause cardiac muscle necrosis

Front 176

capture myopathy

Back 176

- disease of wild animals and birds occurring after a chase, struggle or transport and death often occurs
- animals are weak with muscle rigidity, tremors, and hyperthermia
- myoglobinuria and renal failure may occur
- muscle is edematous with white streaks
- cardiac muscle may have lesions also

Front 177

compartment syndrome

Back 177

- occurs in muscles enclosed by a facial sheath or bone and sheath
- during viborous exercise normal muscle expansion against the inelastic sheath leads to increased intremusclar pressure and occulsion of the blood supply

Front 178

downer syndrome

Back 178

- occurs in recumbent animals lying on one of their limbs
- wt of the body on the limb causes pressure necrosis of the muscle
- disease occurs most commonly in cattle
- can also occur in horses, pigs, large dogs
- prolonged recumbency during anesthesia can induce the lesion

Front 179

crush syndrome

Back 179

- occurs in severe trauma where muscle is lacerated
- subsequent edema, inflammation and hyperemia lead to swelling and increased pressure in the muscle

Front 180

black leg (clostridium chauvoe)

Back 180

- imp dz of ruminants causing myositis, sudden death
- young, feeder cattle and sheep on pasture
- 1+ animals affected & those in best nutritional cond.
- occurs sporadically in certain regions and herds
- pathogenesis uncertain, but latent spores of Clostridium present in muscle- germinate during conds of low O2 tension or trauma in muscle
- no wounds are seen
- any muscle affected, but often pelvis/pectoral girdles
- lesions may be small and in multiple muscles
- sudden death without clinical signs is the usual presentation

Front 181

malignant edema (clostridium speticum)

Back 181

- important disease of ruminants causing myositis and sudden death
- occurs in animals that are confined
- secondary to a wound caused by trauma such as injection, castration, shearing, etc
- mixed clostridial infections may occur but septicum is the most common
- infection usually begins as a cellulitis and spreads to muscle

Front 182

masticatory myositis of dogs (eosinophilic myositis, atrophic myositis)

Back 182

- an immune mediated disease of the muscles of mastication in which Ab is directed aginast the unique type 2M myosin of these muscles
- dogs have recurrent attacks of pain, mandibular immobility and sometimes swelling of themuscles that eventually leads to inability to open or close the mouth and visible atrophy of the muscles
- attacks may last a couple of weeks and occur weeks or months apart
- muslces initially are swollen, dark and streaked with hemorrhage
- later they become atrophic, pale and fibrotic

Front 183

toxoplasma and neospora

Back 183

- protozoal infections of young small animals producing systemic disease that often affects muscle
- the two diseases can only be distinguished with immunologic techniques or electron microscopy
- muscle may be atrophic and have pale streaks or foci

Front 184

sarcocystis

Back 184

- protozoal infection of the muscle of ruminants that is usually an incidental microscopic finding producign no gross lesions in muscle
- rarely the cysts may induce an eosinophilic myositis that is visible as green streaks in heart and other muscles

Front 185

cysticerci

Back 185

- larval forms of the tapeworm of carnivores and form cysts in the heart and skeletal muscle fo the herbivore intermediate host, usually ruminants and pig
- cysts may be visible as small gray or white foci

Front 186

trichinella

Back 186

- nematode whose larva encysts in myofibers
- disease is most imortant in the pig but can be seen in carvnivores that ingest infected pork
- dead larva in muscle may produce pinoint white foci in the muscle, otherwise no gross lesions are seen
- parasite is seen microscopically

Front 187

dermatomyositis

Back 187

- rare inherited disease of collies, sheepdogs adn their crosses affecting muscle and skin
- thought to be immune mediated and affect the muscles of mastication adn the esophagus producign megaesophagus

Front 188

rhabdomyoma (muscle)

Back 188

- very rare tumor of skeletal muscle occurring msot often as a congenital lesion in the heart of lambs and pigs
- also occur in dog larynx
- tumros are pale tan to white and firm
- benign, but can often cause death b/c of their location

Front 189

rhabdomyosarcoma (muscle)

Back 189

- rare tumor
- more common than rhabdomyoma
- tumors are pale tan with hemorrhage and necrosis
- very malignant tumor that readily metastasizes
- occurs most often in the urinary bladder of dogs less than 2 yrs of age

Front 190

leiomyoma (muscle)

Back 190

- uncommon, benign tumor of SM occurring int he GIT of small animals and the female repro tract of large/small animals
- most common tumor of the female repro tract of small animals
- tumors are firm, tan, form discrete nodules within the lumen of affected organs

Front 191

leiomyosarcoma (muscle)

Back 191

- occurs 1/10 as often as leiomyoma and in any organ
- a firm, tan nodular mass that is poorly delinated and may be single or multiple
- metastasize is slow and infrequent

Front 192

diffuse distribution pneumonia- toxins

Back 192

- most common cause of bovine interstitial pneumonia and include 3-methyl indole (a tryptophan metabolite), ingestion of moldy sweet potatoes, the mint perilla frutescens, peanut hay, others
- oxygen (>50% concentration)

Front 193

diffuse distribution pneumonia- viruses

Back 193

- PI3 virus and repsiratory syncytial virus in the bovine
Maedi-visna (retrovirus) in sheep
- porcine reproductive and respiratory syndrome, a disease causing abortion and pneumonia in young pigs
- influenza in pigs and horses
- canine distemper

Front 194

diffuse distribution pneumonia- metabolic conditions

Back 194

- acute respiratory distress syndrome- name given to these pneumonias
- mechanism of action is unknown
- heart failure
- pancreatitis
- DIC
- shock

Front 195

diffuse distribution pneumonia- systemic infections

Back 195

- toxoplasmosis in any species
- salmonella bacteremia in the bovine

Front 196

obliterative bronchiolitis

Back 196

- fibrosis of the lumen as the exudate is organized

Front 197

bronchiectasis

Back 197

- dilation of the lumen caused by weakening of the wall

Front 198

actinobacillus pleuropneumoniae

Back 198

- pigs
- locally extensive pneumonia
- not usually cranial and ventral as are the other diseases
- typical lesion is often unilateral, dorsal, and hemorrhagic

Front 199

bacteria bronchopneumonias

Back 199

- cause of most
- ruminant- mannheimia hemolytica, pasteurella multocida, histophilus somni
- equine- strep, staph, rhodococcus
- porcine- actinobacillus pleuropneumoniae, bordetella
- canine/feline- klebsiella, staph, strep
rat- mycoplasma pulmonis

Front 200

viral bronchopneumonias

Back 200

- important as initiators in many causes of bronchopneumonia, allowing the bacteria to gain a foothold
- at this point th eviral infection is obscured by the bacterial infection
- if the viral infection remains uncontaminated, the pneumonia produced is an interstitial one of hte focal/multifocal distribution