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351 Cards in this Set
- Front
- Back
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Type of immunity that needs to be stimulated to eliminate a viral infection.
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Cell mediated immunity
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This form of immunity involves the secretion of complement and cytokines into the mucus. It is not affected by current vaccines.
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Innate response
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IgA blocks antigens in this region of the equine respiratory tract.
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Upper respiratory tract
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IgG from the local tissue and from the blood blocks antigens in this region of the equine respiratory tract.
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Lower respiratory tract
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Best vaccine form for stimulating cell-mediated immunity
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Modified live vaccine
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True or false: African Horse sickness and Hendra Virus are not commonly seen in the US.
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True
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Most common cause of URT infection in the horse
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Equine Influenza
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Equine influenza is a type... influenza virus.
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Type A
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Change of antigenicity within a viral subtype
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Antigenic drift
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Development of a new viral subtype
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Antigenic shift
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First form of equine influenza identified. No outbreaks since 1977.
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H7N7
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Type of equine influenza implicated in all outbreaks for past 20 years
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H3N8
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Which form of equine influenza is more severe: H7N7 or H3N8?
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H3N8
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How is equine influenza acquired?
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Inhalation
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Viral shedding in cases of equine influenza occurs how long after exposure?
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48 hours
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How long after a clinical bout of equine influenza may clearance mechanisms and respiratory rates be compromised?
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32 days
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Pathologic effects of equine influenza virus.
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Damage to respiratory epithelium
Airway hyper-reactivity |
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Horses most at risk of developing influenza.
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Younger, immuno-naive, foals, debilitated horses
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Incubation period of equine influenza.
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1-5 days
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CS of equine influenza
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Fever
Deep dry cough Serous to mucopurulent discharge Inappetance Swollen LN Myalgia (+/- swollen sheath and limb, pleuritis, pleural pain) |
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Rare conditions associated with H3N8 influenza.
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Myocarditis
Myopathy Purpura hemorrhagica |
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Clin path findings in a horse with influenza.
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Mild anemia
Acute: Leukopenia, lymphopenia Mid course: Neutrophilia Convalescence: Monocytosis Normal fibrinogen if no secondary infection |
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Treatments for equine influenza.
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NSAIDs
Expectorants/Bronchodilators (nebulization) Fluids IV or PO Antivital medications (not very effective) Antibiotics if secondary infection Supportive care |
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Supportive measures for equine influenza include
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Monitoring temperature, RR, pain
Ensure feed and fluid intake, fecal output Soft feed or soaked feed Clean environment with good ventilation Rest for 3 weeks past CS |
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How long should a horse be rested after a bout of influenza?
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3 weeks past resolution of CS
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How is equine influenza diagnosed?
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ELISA (<1 day to results)
VI (Results 1-3 weeks) PCR (Results 1 week) Serology (Collect sample 2-3 weeks after resolution of CS) |
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Method of diagnosis most effective for chronic equine influenza
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Serology
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Foals should be vaccinated for influenza at this age to avoid interference with maternal antibodies.
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9 to 11 months
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How frequently should young performance horses be vaccinated for influenza?
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Every 2-4 months
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How frequently should adult pleasure horses be vaccinated for influenza?
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Every 6-12 months
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Most commonly used vaccine form for equine influenza
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Intranasal
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When should pregnant mares be vaccianted for equine influenza?
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8 weeks before foaling to boost colostral Ab
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Preventative measures for equine influenza
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Isolate new horses for 3 weeks
For sick horses: Caretaker should change clothing, wash hands Recuperating horses: Housed in clean environment |
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Double stranded DNA virus distributed worldwide, infecting most horses by 2 years of age.
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Equine herpesvirus 1 and 4
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Patenogenesis of EHV1-4
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Enters respiratory epithelium
Travels to local lymph Dissemination to other tissues (uterus, CNS) May be latent in resp system or trigeminal ganglion Recrudescence with stress or steroids |
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This virus may cause:
URT infection Late-term abortion Neonatal foal death Myeloencephalopathy Pulmonary vasculotropic infection |
EHV 1-4
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Why are older horses less severely affected by EHV?
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Previous exposure and immune response
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Newest syndrome ID'ed wth EHV 1. Acute onset of fever and respiratory signs, often fatal.
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Pulmonary vasculotropic infection
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A horse dies of pulmonary vasculotropic infection. What will you find at necropsy?
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Severe pulmonary edema secondary to vasculitis
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EHV causes abortion in what trimester?
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Last trimester
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Characteristic of abortus caused by EHV 1
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Minimal autolysis
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Prognosis for a newborn foal with severe respiratory signs, interstitial pneumonia, and inability to nurse as a result of EHV.
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Poor
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Xanthochromic CNS in a neurologic horse should cause you to think...
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EHV
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Treatment of respiratory disease caused by EHV.
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NSAIDs
Expectorants/Bronchodilators Nebulization) Fluids PO or IV Antibiotics for secondary bacteria infections Supportive care |
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Efficacy of acyclovir in treating equine influenza
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Questionable
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Most vaccines we use for EHV are...
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Bivalent
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Can a MLV vaccine for EHV be used in a pregnant mare?
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Yes but don't, lest you be blamed for an unrelated abortion.
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ssRNA virus first ID'ed in 1953 in an outbreak of abortion and respiratory disease. Worldwide distribution
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Equine Viral Areritis
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Pathenogenesis of EVA.
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Aerosolized, contact with infected horses, venereal transmission
Cell associated viremia and replication: Macs, endothelium, mesothelium Paravasculitis |
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CS of EVA
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Usually resp infections are subclinical
Fever, nasal d/c, inappetance, depression, lymphadenopathy, coughing Conjunctivitis, edema of periorbital region Dependent edema Foals: Fatal interstitial pneumonia Abortion |
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What distinguishes abortion caused by EVA from abortion caused by EHV?
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EVA: May occur earlier. Fetus autolysed.
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Stallions specifically may be persistent carriers of this viral disease for weeks or years.
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Equine Viral Arteritis
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Populations that should be vaccinated for EVA.
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Breeding colts 6-12 months of age
Seronegative mares before being bred to positive stallion |
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Complication of vaccinating a horse for EVA
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Becomes seropositive, makes overseas travel difficult
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What should be done if you wish to breed a mare negative for EVA to a positive stallion?
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AI or vaccinate mare
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Equine rhinitis causes disease in this popuation
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Young horses
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Incubation period of equine rhinitis
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3-8 days
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Equine rhinitis virus is shed in....
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Nasal secretions, urine, feces
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Unlike other equine viruses, what makes equine rhinitis unique?
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Wide host range
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Diseases caused by EHV-2
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Upper respiratory disease
Pneumonia Ocular disease |
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Age group affected by EHV-2
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2-3 month old immunocompromised foals
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Transmission of EVA
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Aerosol, fomites, vertical, venereal
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Incubation period of EVA
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3-14 days
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Tests to diagnose EVA
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VI (Results 1-3 weeks)
PCR (Results < 1 week) Serology (Results 2-3 weeks) |
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Tests to diagnose EHV
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VI (R 1-3 weeks)
PCR (R < 1 week) FAB (R 24h) Serology (R 2-3 weeks) |
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How long should a mare vaccinated for EVA be isolated after breeding?
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21 days
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Vaccine protocol for EHV
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Foals: 6 months, then boost 3-4 weeks, and 8-12 weeks after first dose.
Broodmares: months 5,7,9,11 of gestation with KV |
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Most common bacterial respiratory disease of horses
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Strangles
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Microscopic characteristics of Strep equi
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G+, chain forming, B-hemolytic, facultative anaerobe
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Where does S. equi replicate in the horse?
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LN of the head
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"Bastard strangles" is caused when S. equi...
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Spreads through lymphatics to other areas of body
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Condition that occurs when S. equi elicits an immune reaction and Ab-Ag complex deposition
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Pupura hemorrhagica
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Horses most likely to have severe strangles.
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Old, young, debilitated, naive, crowded populations
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Mortality with strangles is about this percentage.
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2-3%
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How is strangles transmitted?
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Horse-to-horse contact
Fomites (oral and nasal) |
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"Cattier" horses with S equi may harbor the pathogen within...
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Guttural pouch
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Incubation period for strangles
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1-14 days
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Duration of disease with strangles
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2-4 weeks
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Swollen LN are visible this long after S. equi exposure.
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2-3 days
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LN that tend to abcess with S. equi infection
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Submandibular
Retropharyngeal |
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Where do abcessed retropharyngeal LN typically drain?
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Mediial floor of guttural pouch
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Primary source of environmental contamination with S. equi.
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Ruptured abcesses
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CS of bastard strangles
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Weight loss
Low grade fever Elevated WBC count Elevated fibrinogen |
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Organs commonly affected with purpura hemorrhagica and vasculitis caused by S. equi.
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Kidneys, heart, liver
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Describe atypical strangles.
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Subclinical disease or mild disease
Due to bacterial load, pathenogenesis, poor exposure, horse-specific characteristics |
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Three components of classic strangles:
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Upper respiratory infection and abcess
Bastard strangles Purpura hemorhhagica |
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How is strangles diagnosed?
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Bacterial culture
PCR Serology |
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Serologic tests for strangles detect...
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Antibodies to SeM protein
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Problem with serologic testing for S. equi
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Cross reaction with other Streptococcus species (Like S. zoo)
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True or false: Horses with non-ruptured abcesses due to strangles are prime cases for antibiotic treatment
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False
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How should an uncomplicated strangles case be managed?
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Hot packs for abcesses
Supportive care and isolation |
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When are antibiotics and NSAIDs indicated for treatment of S. equi?
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Horse very uncomfortable, depressed, anorexic, or after abcess has ruptured
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How should asymptomatic at-risk horses on a farm with a strangles outbreak be managed?
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Take temp daily
If febrile, start abx immediately |
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How effective are vaccinations for prevention of strangles?
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IM: Low efficacy, high risk SE
IN: Poor efficacy |
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How should a horse with strangles be tested to determine whether or not the infection has been cleared?
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Endoscopy, PCR, culture until negative
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Normal flora in horse's URT, sometimes cross-reacts on serologic tests with S. equi.
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S. zooepidemicus
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When are some occasions on which normal URT flora may cause disease?
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Following viral infection
Foals |
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List two fungal infections seen in the lower airway of the horse.
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Aspergillus
Fusarium |
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Horses most at risk of acquiring fungal pneumonia
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Compromised, young, very sick
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Two sources of infection for fungal pneumonia.
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Gut
Inhaled |
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Treatments for fungal pneumonia
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Amphotericin B (Nephrotoxic)
Fluconazole Miconazole |
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Inexpensive, good topical treatment for fungal pneumonia
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Miconazole
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Major SE of amphotericin B
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Nephrotoxic
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Used to treat candidiasis in foals
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Fluconazole
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Lung parasite seen in horses who have has contact with a donkey.
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Dictyocaulus arnfeldi
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Treatment for Dictyocaulus arnfeldi
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Ivermictin
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Parascarids are responsive to these drugs.
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Ivermectin
Power Pack |
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Three causes of pleural effusion in the horse.
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Pulmonary lymphatic blockage by pneumonic exudate
Thoracic neoplasia Penetrating wound/trauma |
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Stressors that may lead to infectious pleuritis.
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Transport
Recent viral infection Strenuous exercise General anesthesia |
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CS of pleuropneumonia
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Depression, inappetance, acute wt loss
Fever Tachycardia Variable dyspnea and pain Reluctance to move, base wide stance Soft reluctant cough Mucopurulent nasal discharge Ventral edema Scant dry feces |
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Amplified chest sounds may be the result of
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Pleural effusion
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Diagnosis of pleuropneumonia based on...
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Hx and CS
Percussion CBC, Chem, blood gas U/S Rads |
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Best diagnostic tool to diagnosis pleuropneumonia
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Ultrasound
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Comet tails seen on US are indicative of...
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Thickening of pleural membranes
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SItes for thoracocentesis
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IC 7 or 8 on left
IC 6 or 7 on right |
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Parameters that should be checked with thoracocentesis
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Cytology
Culture and sensitivity Glucose and pH |
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Clin path signs of acute pleuropneumonia
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Hemoconcentration
Leukopenia with LS Azotemia |
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Clin path signs of chronic pleuropneumonia (past 4-7 days)
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ACD
Laukocytosis with neutrophilia Hyperfibrinogenemia Low albumin and gammaglobulin |
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Leukopenia with left shift is an indicator of pleuropneumonia caused by...
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Gram negative bacteria
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Treatment for pleuropneumonia
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Broad spectrum Abx (G+/G-, aerobic/anaerobic, mixed infection)
(Penicillin, aminoglycosides, MTDZ) Control infalmmation and fibrin with NSAIDs, pentoxyfiliine, DMSO, and recombinant TPA. Prevent laminitis FLuids and nutritional support |
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Does the horse have a complete or incomplete mediastinum?
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Incomplete
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Treatments for pleuropneumonia.
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Thoracoscopy
Thoracotomy with rib resection |
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What should be done if a horse develops pneumothorax with a thoracoscopy?
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Close entry site, remove air, wait.
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How long does it take for a thoracotomy and rib recection to heal?
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4-5 months with persistent rib defect
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Prognosis of acute pleuropneumonia with minimal effusion and fibrosis
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Good
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Prognosis of chronic pleuropneumonia with significant lung consolidation, effusion, and fibrin tags
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Poor
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Indicators of a poor prognosis with pleuropneumonia.
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Malodorous breath with serosanguinous discharge
Malodorous pleural effusion with mixed bacteria Anaerobic bacteria in pleural fluid Poor response to therapy |
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Overall prognosis for return to work following pleuropneumonia.
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61% return to work
(89% racing TB return to racing) |
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Common complication following thoracotomy for treatment of pleuropneumonia
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Laminitis
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List some causes of granulomatous lung disease in the horse.
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Silicosis or hairy vetch toxicosis
Fungal, bacterial, coccidial, parasitic disease |
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Equine miltinodular pulmonary fibrosis is associated with this virus
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EHV 5
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Treatment for equine multinodular pulmonary fibrosis
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Corticosteroids
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Prognosis of equine multinodular pulmonary fibrosis
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Guarded to poor
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Multisystemic eosinophilic epitheliotropic disease causes this histologic sign
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Eosinophilic infiltrates in lungs and other tissues
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Clinical signs associated with multisystemic eosinophilic epitheliotropic disease
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Respiratory disease
Weight loss Skin lesions Eosinophilia in blood |
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Treatment for multisystemic eosinophilic epitheliotropic disease
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Corticosteroids
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Homogenous graying of the lungs on radiograph is indicative of...
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Infiltrative disease
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Most common neoplasia of the lower respiratory tract in the equine
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Granulosa cell tumor
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This neoplasm snakes its way up the airways and is visualized on endoscopy
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Granulosa cell tumor
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Clinical signs associated with a respiratory granulosa cell tumor resemble those of...
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RAO or obstructive disease
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Extensive ossification around the physes of the limbs, associated with thoracic neoplasia.
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Hypertrophic osteodystrophy
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Prognosis of granulosa cell tumor in the lower airways
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Poor
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Most common cause of aspiration pneumonia in the horse
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Laryngeal dysfunction
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Causes of pneumothorax
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Penetrating wound
Dissecting SQ emphysema Bullae or ruptured bronchi Necrotic process (infiltrative or neoplastic) causing bronchoplaural fistula |
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CS of pneumothorax
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Restlessness to anxiousness
Tachypnea/Tachycardia Flared nostrils, abdominal component to respiratory effort Asymmetric thoracic movement Cyanosis in end-stage |
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Absence of chest sounds with increased resonance on percussion is indicative of...
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Pneumothorax
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Most useful tests for diagnosis of pneumothorax
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Ultrasound and radiograph
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Treatment for pneumothorax in the horse
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Nasal oxygen
Reinflate chest with teat cannula and suction Pretreat post-inflation reaction with prophylactic steroids ID and stop leak Abx and laminitis preventative |
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What peroportion of horses with pneumothorax die from primary disease or secondary complications?
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40%
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Complications of re-inflation of a collapsed lung in the horse
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Pneumonia and inflammation
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CS of pulmonary edema
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Harsh lung sounds
Tracheal fluid Respiratory distress |
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Treatment of pulmonary edema
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Treat underlying disease (cardiac function?)
Furosemide 1 mg/kg Nasal O2 Corticosteroids Bronchodilators (Clenbuterol) Hetastarch or plasma to increase oncotic pressure |
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How common is pericarditis in horses?
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Uncommon
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Three forms of pericarditis
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Effusive
Fibrinous Constrictive |
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Causes of pericardial disease in the horse
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Hematogenous
Pleural/lung infection Viral or bacterial infection Neoplastic Trauma Immune mediated Hemorrhagic Idiopathic |
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CS of pericardial disease in the horse
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Fever, lethargy, anorexia, ventral edema, wt loss
Ataxia, tachypnea, tachycardia, jugular pulse Muffled heart sounds, arrhythmia (uncommon) |
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Why is ECG not very diagnostic in the horse?
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Purkinje fibers disperse more completely so changes in electrical conduction are harder to detect
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Site for pericardiocentesis in the horse
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5th ICS above olecranon
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Treatment for pericardial disease in the horse
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Drain sac
Antimicrobials PRN NSAIDs Indwelling pericardial tube Lasts 3-15 weeks |
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Px of pericardial disease
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Guarded to poor
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Inflammation of the cardiac muscle
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Myocarditis
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Causes of myocarditis
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Blister beetle
Japanese Yew Infectious: Influenza, EIA, EVA, S. equi Immune mediated Ionophore Abx (monensin, lasalocid) |
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CS of myocarditis in the horse
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Ataxic, lethargic, depressed, staggering, recumbent
Tachycardia, tachypnea, thready pulse, jugular pulse, ventral edema |
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Clin path findings in horse with myocarditis
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Azotemia
Elevated liver enzymes and bilirubin Elevated LDH Elevated Troponin I |
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Treatment for myocarditis
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Remove underlying cause
Provide supportive cardiac medication Supplement magnesium and potassium Stall rest/limited exercise for 8 weeks |
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How long after a bout of myocarditis should a horse be rested?
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8 weeks
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Prognosis of equine myocarditis
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Poor
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CS of vasculitis
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Related to affected organ system
Hyperremia, petechial and ecchymotic hemorrhages Well demarcated areas of cutaneous edema Ventral edema |
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Two pathogens that can cause Equine Purpura Hemorrhagica Syndrome
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Streptococcus or Influenza
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How long after infection with S. equi or inflenza does purpura hemorrhagica present?
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2-4 weeks
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This disease can cause necrotizing vasculitis, fever, and is diagnosed with a Coggins test.
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Equine infectious anemia
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Disease caused by Anaplasma phagocytophilum.
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Equine ehrlichiosis
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CS of equine ehrlichoisis
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Fever, depression
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How is equine ehrlichiosis diagnosed?
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Plieomorphic inclusion bodies in PMN
Eosinophilia |
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Treatment for equine ehrlichiosis
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Oxytetracycline
Doxytetracycline |
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Most common cause of vasculitis in the horse
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Drug-induced
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Three drug classes that may induce vasculitis in the horse.
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Penicillin
Sulfonamides Quinolones |
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Treatment for vasculitis
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Remove the cause
Glucocorticoids Pentoxyphilline Anti-inflammatories (NSAIDs, antihistamines, cytotoxic drugs, immunosuppressive drugs) |
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Signalment of typical horse with RAO
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Middle aged, older horse with recurrent, chronic respiratory disease
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CS of RAO
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Bronchoconstriction
Moderate cough and mucus Moderate exercise intolerance Nostril flare, abdominal push Progressive |
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This progressive respiratory disease results from an inappropriate response to antigenic stimulation
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RAO
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Possible antigens responsible for triggiering RAO
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Molds
Actinomycetes Endotoxin (feces) Barn mites Humidity, tree pollen, grasses |
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Inflammation and bronchoconstriction are hallmarks of...
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RAO
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Results of inflammatory activation in the equine airways.
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Hyperesponsiveness
Bronchoconstriction Increased mucus Direct injury |
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A normal horse will tolerate a rebreathing bag for about...
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2 minutes
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Concern when evaluating older horse for RAO
|
Other disease processes may be going on
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Describe the atropine test for RAO.
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Atropine dries mucus secretions and bronchodilates. Give 1 dose to horse and if horse's CS improve for 15 mins or so then RAO is the diagnosis. Absence of improvement does not rule out RAO.
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Is BAL or TTW better for evaluating the RAO horse? Why?
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BAL will give a better picture of current inflammation in the lower airways
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To evaluate a BAL, the following tests should be done
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Gram stain
Cell count Culture |
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This bacteria will likely be found on a TTW of a horse with heaves.
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Strep. zooepidemicus
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Microbes of greatest concern on a BAL
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Gram negatives and intracellular bacteria
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True or false: Thoracic rads may be used to gauge a horse's ability to recover from an RAO attack.
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False
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Type of radiographic pattern seen in a horse with RAO.
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Bronchial
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Two components of the RAO clinical score
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Abdominal breathing
Nasal flare |
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How well does the severity of clinical signs with RAO correlate with the severity of airway disease?
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Poorly. Once clinical evidence of disease is seen, the horse is very compromised.
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Environmental changes to alleviate RAO
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Eliminate hay
Eliminate access to dusty barn Eliminate dusty run-in-shed Eliminate round bales Provide pasture with shade Slowly reintroduce some of these |
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This part of the autonomic nervous system innservates right to the bronchial smooth muscle
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Parasympathetic
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Main neurotransmitter associated with the parasympathetic nervous system
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Acetylcholine
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At the parasympathetic nerve-smooth muscle interface in the respiratory system, what happens when the M3 receptor is stimulated?
|
Bronchoconstriction
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At the parasympathetic nerve-smooth muscle interface in the respiratory system, what happens when the M2 receptor is stimulated?
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Decreased relaxation
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This drug binds receptors to block ACh binding so that bronchial smooth muscle (or any smooth muscle) will not constrict.
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Atropine
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Is atropine a parasympathomimetic or parasympatholytic drug?
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Parasympathomimetic
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Why is atropine not a long term drug of choice for RAO?
|
Short acting and causes gut stasis
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What kind of drug is ipratropium bromide? How is it delivered?
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Parasympathomimetic
Aerosol |
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Onset of ipatropium bromide
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15 minutes
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Duration of ipatropium bromide
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4-6 hours
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Why may aerosolized drug delivery be ineffective in a horse with severe RAO?
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Mucus and lung edema interfere with delivery of aerosolized drug
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Source of epinephrine
|
Adrenal medulla
|
|
|
Source of norepinephrine
|
Neuromuscular junction
|
|
|
Functions of alpha-2 receptors in the respiratory system
|
Increase mucus and water transport
Prejunctionally decrease Ach release at NMJ |
|
|
Functions of beta-2 receptors in the respiratory system
|
Bronchodilation
Increased mucus secretion Increased mucociliary clearance |
|
|
Do beta-2 receptors have a higher affinity for epinephrine or norepinephrine?
|
Epinephrine
|
|
|
Are alpha agonists or beta agonists utilized for treatment of RAO?
|
Beta
|
|
|
Clenbuterol and albuterol belong to this class of frugs
|
Beta 2 agonists
|
|
|
Is albuterol or clenbuterol available in aerosol form?
|
Albuterol
|
|
|
Side effects of beta agonist (albuterol/clenbuterol) therapy for RAO.
|
Elevated HR
Sweating Muscle fasiculations |
|
|
Does albuterol or clenbuterol cause more side effects in the horse? Why?
|
Albuterol, more B1 affinity
|
|
|
A horse receives a dose of clenbuterol then begins sweating profusely. The heart rate shoots up for about 20 minutes. How should this case be managed?
|
Give horse a break for 24 hours then try a half-dose of clenbuterol.
|
|
|
Furosemide has this effect on the respiratory system.
|
Bronchodilation for 6-8 hours
|
|
|
How useful are antihistamines for management of RAO in horses?
|
Not very useful unless combined with steroids, b/c there is not much mast cell involvement in RAO.
|
|
|
True or false: NSAIDs are ineffective at treating airway inflammation.
|
True
|
|
|
Steroids delivered by this route are more expensive but have fewer side effects.
|
Inhaled
|
|
|
Steroids delivered by this route are cheaper but have more side effects.
|
Systemic
|
|
|
How are dexamethosone and prednisolone delivered for the treatment of RAO?
|
Systemic
|
|
|
How are beclomethasone diproprionate and fluticasone delivered for the treatment of RAO?
|
Inhaled
|
|
|
Function of cromolyn
|
Mast cell stabilizer
|
|
|
How can cromalyn (mast cell stabilizer) be administered for treatment of RAO?
|
Weeks before predicted challenge
|
|
|
Why is prednisone not used for treatment of RAO?
|
Has to pass thru liver and become prednisolone to be active. Inefficient process in horse.
|
|
|
Benefits of aerosolized drug delivery in horses with RAO.
|
Least SE
Best for maintenance and mild-moderate RAO cases |
|
|
Downsides of aerosolized drug therapy in horses with RAO.
|
Costly
Owner compliance |
|
|
Best mode of drug delivery in horses with severe RAO
|
Systemic
|
|
|
Systemic drug of choice for initial management of severe RAO.
|
IV dexamethosone
|
|
|
How should Lasix be used in management of an RAO case?
|
One dose in conjunction with long-term therapy to provide quick broncodilation
|
|
|
Treatment plan for horses with mild RAO.
|
Change environment
Brochodilator therapy Inhaled steroids |
|
|
Treatment plan for horses with severe RAO.
|
Change environment
Systemic dexamethosone and clenbuterol Oxygen (+/-) May switch to inhaled meds later |
|
|
When treating an RAO case, when can steroid doses begin to be tapered back?
|
After horse has responded to treatment
|
|
|
True or false: With proper therapy, RAO may be cured in some cases.
|
False. RAO is not curable
|
|
|
List some of the chronic changes seen with horses with uncontrolled RAO
|
Persistent inflammatory cells
Increased goblet cells Increased mucus viscosity Injury to mucociliary clearance Smooth muscle thickening Collapse of airways Persistent bacterial infection Secondary cardiac disease |
|
|
Collapse and auto-digestion of small bronchi
|
Bronchomalacia
|
|
|
This test should be done before taking a horse with RAO off of steroids
|
BAL, to check for inflammation
|
|
|
A young racehorse with no significant medical history presents with a persistent, intermittent cough, mild nasal discharge, and tracheal mucus. No response to antibiotics has been seen. This is a classic presentation for...
|
Inflammatory airway disease
|
|
|
True or false: Inflammatory airway disease cases usually make a complete recovery
|
True
|
|
|
How long does the average course of inflammatory airway disease last?
|
7 weeks
|
|
|
Which disease will have more neutrophils in airway secretions: RAO or IAD?
|
RAO (70-90% PMN vs 5-20%)
|
|
|
This non-infectious airway disease is associated with a change from pasture to the racetrack/training environment.
|
Inflammatory airway disease
|
|
|
What is the proposed etiology of IAD?
|
Sudden exposure to high level of airway disease
|
|
|
Describe the cycle initiated when airway inflammation takes place.
|
Inflammation injures respiratory lining
Injured lining initiates more inflammation Mucus becomes more tenacious and sticky and mucociliary clearance impaired More injury |
|
|
Does inflammatory airway disease have an infectious cause?
|
No
|
|
|
How is a diagnosis of inflammatory airway disease made?
|
Clinical signs: Cough, mucus, exercise intolerance
Horse's breed, use, age, history |
|
|
In some cases, this may be the only evidence of IAD
|
Lower airway mucus
|
|
|
Categories of inflammatory airway disease, as identified on BAL.
|
Type 1: PMN
Type 2: PMN mixed with mast cells Type 3: PMN mixed with eosinophils |
|
|
Most common category of IAD
|
Type I (increased neutrophils)
|
|
|
Is TTW or BAL better for culture of airway secretions?
|
TTW
|
|
|
Is TTW or BAL better for assessment of cells in whole lung?
|
TTW
|
|
|
Is TTW or BAL better for sampling of the lower airways?
|
BAL
|
|
|
Which lung lobe is primarily sampled with BAL?
|
Right dorsal diaphragmatic
|
|
|
Which test is better for ruling out lower airway inflammation: TTW or BAL?
|
BAL
|
|
|
Which test is better for ruling out an airway infection: TTW or BAL?
|
TTW
|
|
|
Which test should be done first if both are to be done: TTW or BAL?
|
TTW
|
|
|
How should cases of inflammatory airway disease be managed?
|
Get horse away from dust: Out of barn, out on grass
No round bales Feed on the ground Wet down dirt barn aisle |
|
|
Treatment of this grade of IAD is the same as for RAO: Corticosteroids and bronchodilators
|
Type I IAD
|
|
|
Mast cell stabilizers are used to treat this type of IAD
|
Type 2 IAD
|
|
|
Antihistamines are used to treat this type of IAD
|
Type 3 IAD
|
|
|
Pulmonary hypertension can cause this condition in racehorses
|
Exercise induced pulmonary hemorrahge
|
|
|
Source of the blood in EIPH
|
Pulmonary vacular system
|
|
|
Risk factors for EIPH
|
Steeplechase horses
Older horses Females |
|
|
How is EIPH diagnosed?
|
BAL ideally +/- endoscopy
|
|
|
Does EIPH happen in dorsal or ventral lung fields?
|
Dorsal
|
|
|
Treatment for EIPH
|
Furosemide
Nasal dilators Corticosteroids Equine concentrated serum? |
|
|
What is the consequence of cutting the tracheal rings in foals during tracheostomy?
|
Sticture formation
|
|
|
Should an initial URT endoscopic exam be sedated or unsedated?
|
Unsedated to gauge laryngeal function
|
|
|
Medications that may be given for upper airway inflammation
|
Throat spray (DMSO + dexamethosone) fo 10 days
Prednisolone in decreasing dosage NSAIDs 7-10 days Oral antibacterial 5-10 daus |
|
|
Epidermal inclusion cyst containing squamous and keratin debris. May be drained through false nostril if cosmetic issue.
|
Atheroma
|
|
|
Where in the nasal cavity do nasal polyps attach?
|
Caudal nasopharynx
|
|
|
How are nasal polyps removed?
|
Amputate with cutting loop or OB wire in tube
|
|
|
Do reduntant alar folds cause obstruction of the nasal cavity?
|
No, just noise
|
|
|
Redundant alar folds must be diagnosed with horse in motion b/c...
|
Fluttering heard with movement of air
|
|
|
Preferred treatment for redundant alar folds.
|
Flair nasal strips
|
|
|
Continuous steady dripping (not perfuse)of fresh blood from the nares is due to...
|
Nasal mucosal hemorrhage
|
|
|
Etiology of nasal mucosal hemorrhage
|
Unknown
|
|
|
Is nasal mucosal hemorrhage typically unilateral or bilateral?
|
Unilateral
|
|
|
How is nasal mucosal hemorrhage treated?
|
Coagulation with laser
Cut vessel and pack off tightly |
|
|
Failure of buconasal membrane rupture in early gestation.
|
Choanal atresia
|
|
|
Prognosis of bilateral choanal atresia
|
Fatal at birth without tracheostomy
|
|
|
Difficulty with "poking a hole" in membrane causing choanal atresia.
|
Wants to close back up
|
|
|
Nasal discharge of milk in a foal is a sign of either...
|
Cleft palate
Underdeveloped swallowing |
|
|
Pharyngeal scar constricting the airway is called a...
|
Pharyngeal cicatrix
|
|
|
Three causes of epistaxis in the horse
|
Nasal mucosal hemorrhage
Ethmoid hematoma Guttural pouch mycosis |
|
|
A horse has a nosebleed! You look and there seems to be a dripping of old, black, stagnant looking blood. This is most consistent with the appearance of,...
|
Ethmoid hematoma
|
|
|
Structured benign mass on the ethmoturbinates or in the sinus, with the consistency of blackberry jam. When the capsule breaks, a dripping of blood may be seen from the nose. What is this lesion?
|
Ethmoid hematoma
|
|
|
Treatments for pharyngeal ethmoid hematoma
|
Radiograph for sinus involvement
Debulk before lasing Formalin injection Electrosurgical loop OB wire loop |
|
|
Rate of recurrence of ethmoid hematoma
|
12% (less if completely removed)
|
|
|
How does guttural pouch tympany occur?
|
Salpingopharyngeal osteum becomes a one-way valve trapping air in one or both guttural pouches
|
|
|
How is unilateral guttural pouch tympany relieved?
|
Fenestrate median septum and allow unaffected side to empty air
|
|
|
How is bilateral guttural pouch tympany relieved?
|
Fenestrate median septum and relieve salingopharyngeal obstruction on one side
OR Relieve both pharyngeal openings |
|
|
True or false: Laser fenestration of the medial septum of the guttural pouch may be done in the standing horse.
|
True
|
|
|
Major structures apposing the ventral aspect of the guttural pouch
|
Carotid arteries
Pharyngeal nerves |
|
|
Possible complication of damaging the vagus nerve as it runs close to the guttural pouch.
|
Dysphagia
|
|
|
Term for pus in gutural pouch
|
Empyema
|
|
|
Common site of rupture of the retropharyngeal lymph nodes
|
Into the guttural pouch
|
|
|
Risk of lancing an abcess in the guttural pouch
|
Chronic infection possible
|
|
|
If you see unruptured abcessed in the guttural pouch, should they be lanced?
|
No
|
|
|
Ideal surgical approach for entry into the guttural pouch.
|
Viborg's triangle
|
|
|
Severe epistaxis with gushing fresh blood is likely due to...
|
Guttural pouch mycosis
|
|
|
Prognosis of untreated guttural pouch hemorrhage.
|
Fatal on 2nd or 3rd hemorrhage
|
|
|
What is the underlying problem with carotid erosion in the guttural pouch?
|
Arterial wall defect
|
|
|
Treatment for guttural pouch mycosis
|
Embolization of regional arteries
|
|
|
Two major arteries against which fungal plaques may form in the guttural pouch
|
Internal carotid
Maxillary |
|
|
CS of guttural pouch mycosis
|
Profuse arterial hemorrhage
|
|
|
Arteries that should be blocked in a horse with guttural pouch mycosis
|
Maxillary
Internal Carotid Occipital |
|
|
Arterial occlusion for the treatment of guttural pouch mycosis should be done under what kind of guidance?
|
Fluoroscopy
|
|
|
How will an entrapped epiglottis appear immediately after it is freed?
|
Ischemic at tip, reddens after freedom and tip will atrophy
|
|
|
Recovery time following surgery for epiglottic entrapment
|
Weeks to months
|
|
|
Consequence of inadequate recovery time following surgery for an entrapped epiglottis
|
Reentrapment
|
|
|
Dorsal displacement of the soft palate occurs most frequently in this group of horses...
|
Racehorses
|
|
|
Factors that contribute to dorsal displacement of the soft palate
|
Pharyngitis
Food aspiration Denervation and loss of soft palate tone |
|
|
Moat common cause of dorsal displacement of the soft palate
|
Upper airway irritation
|
|
|
Treatments for dorsal displacement of the soft palate
|
Relieve inflammation
Tongue tie Strap muscle resection/ Sternothyroideus tenectomy Trim soft palate Laser soft palate to stiffen it Tie forward |
|
|
When tying forward the pharynx, suture is passed through the .... and wrapped around the...
|
Thyroid cartilage
Basihyoid bone |
|
|
First choice treatment for repair of dorsal displacement of the soft palate
|
Sternothyroideus tenectomy
|
|
|
Current approach to dorsal displacement of the soft palate
|
Standing sternothyroideus tenesctomy
Soft palate laser Heal 2 weeks, then train Tie forward if not effective |
|
|
Paresis of this nerve is responsible for most laryngeal hemiplegia
|
Left recurrent laryngeal nerve
|
|
|
Grade of laryngeal hemiplegia where there is asynchronous movement but full abduction is possible with stimulation.
|
Grade II
|
|
|
Grade of laryngeal hemiplegia where there is asynchronous movement and full abduction cannot be induced.
|
Grade III
|
|
|
Grade of laryngeal hemiplegia where there is no movement during any phase of respiration.
|
Grade IV
|
|
|
Treatments for left laryngeal hemiplegia
|
Prosthetic laryngoplasty
Ventriculocordectomy Partial arytenoidectomy Pedicle graft |
|
|
A prosthetic laryngoplast replaces this muscle with 2 sutures
|
Cricoarytenoideus dorsalis
|
|
|
Complications with tie back proceedure for laryngeal hemiplegia
|
Aspiration pneumonia
|
|
|
The effects of this treatment for laryngeal hemiplegia are only seen during exercise
|
Neuromuscular pedicle graft
|
|
|
True or false: Ventriculochordectomy will not grow back.
|
True
|
|
|
Most common causes of right laryngeal hemiplegia
|
Retropharyngeal inflammation
IV injection injury to RLN |
|
|
Thickened and stretched aryepiglottic fold and airway obstruction are part of this syndrome. Exacerbated by heat.
|
Arytenoid chondritis
|
|
|
Prognosis of mucosal arytenoid lesions
|
Pretty good. In one study 15/19 resolved w/o complication or treatment.
|
|
|
Does arytenoid chondritis appear earlier in athletes or non-athletes?
|
Athletes
|
|
|
CS of arytenoid chondritis
|
Coughing
Upper airway inspiratory noise during exercise Exercise intolerance |
|
|
While scoping a horse you see a granulomatous bud on the arytenoid cartilage. It is also immobile. These are signs of...
|
Arytenoid chondritis
|
|
|
Ruleouts for swollen immobile arytenoid cartilage on the left side.
|
Left laryngeal hemiplegia
Arytenoid chondritis |
|
|
Lesions in the caudodorsal region may not be arytenoid chondritis, but...
|
Infected tieback suture
|
|
|
Treatment for confirmed superficial lesions of larynx
|
Anti-inflammatory throat spray
Systemic abx and anti-inflammatories Airway REST |
|
|
Treatment of potentially curable AC
|
Laser assisted debridement thru trocar in cricothyroid membrane
OR Conventional debridement through standing larynngotomy |
|
|
Risk factor associated with partial arytenoidectomy
|
Aspiration of food
|
|
|
With a partial arytenoidectomy, what post-operative treatments are indicated?
|
ANti-inflammatory throat spray
Decreasing prednisone Phenylbutazone Oral antibiotic Granulation tissue? Inject with steroid |
|
|
With a partial arytenoidectomy, what should be preserved?
|
Some mucosa to form a seal against swallowing
|
|
|
Injection of this material may cause swelling of the arytenoid mucosa following partial removal, preventing leakage for 3 months
|
Teflon
|
|
|
Blood draining from the sinus cavities likely due to...
|
Ethmoid hematoma
|
|
|
List some causes of sinus disease
|
Primary sinusitis
Dental sinusitis Synus cysts Fractures Tumor masses |
|
|
How is sinus disease managed medically?
|
Rule out masses, etc.
Culture and sensitivity Frontal sinus lavage Systemic antimicrobials (temporary) |
|
|
True or false: Any time a sinus cyst is detected in the horse, it should be removed.
|
False. Only if CS.
|
|
|
Only useful indication for maxillary sinus flap formation.
|
Tooth extraction
|
|
|
When excising sinus wall masses form a horse, significant bleeding occurs. What do you do?
|
Pack down with gauze, stop proceedure, let clot for 3 days then reopen sinus flap to remove packing. 40% horses need other issues addressed on 2nd sinus proceedure.
|
|
|
Treatment for sinusitis
|
Isolate source of drainage
Culture Lavage Systemic antibiotic therapy Refer for surgery if recurrent and drainage is active. |
