Equine Top 20 Diseases - Part 1 Flashcards
what is the classic case presentation of a corneal ulcer in a horse?
acute onset of unilateral blepharospasm, photophobia, miosis, epiphora, & corneal edema
how is a corneal ulcer diagnosed?
thorough ophthalmic exam with ophthalmoscope & fluorescein staining positive
what surgery can be done for severe corneal ulcer cases in a horse?
conjunctval grafts
what treatment can be used for a corneal ulcer on a horse that is difficult to handle or has a severe ulcer?
subpalpebral lavage system
what drug should never be used if a corneal ulcer is present?
steroids
what is the main differential for a corneal ulcer in a horse? how do you rule it out? how do you treat it?
recurrent uveitis - has similar clinical signs but no fluorescein uptake that is treated with topical steroids
what are 2 conditions that are sequelae to corneal ulcers? why might they be missed?
desmetoceles & stromal abscesses - they have no stain uptake because all endothelium is gone or covered over
what drugs are used to treat corneal ulcers?
topical antimicrobials, atropine to decrease iridocyclospasm/improve drainage, & anti-collagenases
what is the classic case presentation of a horse with sinusitis?
mucopurulent unilateral nasal discharge +/- facial swelling, epiphora & often malodorous
how is sinusitis in a horse diagnosed?
radiographs to identify sinus or tooth pathology, upper airway endoscopy to evaluate drainage angles/rule out other causes of discharge, & thorough dental exam
how is sinusitis treated in a horse?
sinus trephination/flap/lavage, +/- removal of offending tooth or mass, & long-term antibiotics
what is the typical cause of primary sinusitis?
upper respiratory infection
what is more common: primary or secondary sinusitis?
secondary
what are the main causes of secondary sinusitis in a horse?
dental disease, sinus cyst, ethmoid hematoma, or neoplasia
T/F: chronic sinusitis in a horse has a guarded prognosis for resolution
TRUE
what is another name for equine cushing’s disease?
pituitary pars intermedia dysfunction
what is the classic case presentation of a horse with cushing’s disease?
horse/pony over 15 years old with chronic laminitis, hypertrichosis, recurrent infections (hoof abscesses & sinusitis), loss of topline musculature, lethargy, abnormal fat deposition (supraorbital fat pads), & PU/PD/PP
how is equine cushing’s disease diagnosed?
increased resting plasma ACTH, positive thyrotropin-releasing hormone stimulation test, & measure fasting insulin/insulin sensitivity because most horses with PPID also have insulin dysregulation
how is equine cushing’s disease treated?
daily pergolide (dopamine agonist) may have to increase dose over time as disease progresses
what is the pathogenesis of equine cushing’s disease?
lack of dopaminergic inhibition of the pituitary pars intermedia by the hypothalmus which leads to the development of functional adenoma in pituitary pars intermedia (will see increased ACTH, alpha-MSH, beta-endorphin, & cortisol levels)
T/F: younger horses with regional adiposity, laminitis, & insulin dysregulation are usually considered to have equine metabolic syndrome & not equine cushing’s
TRUE
what is the classic case presentation of a horse with colitis?
depression, inappetance, variable colic, decreased or hypermotile gi sounds, fever, variable degrees of shock/hypopefusion, +/- watery hemorrhagic diarrhea
what does a fecal PCR test for in a horse with colitis?
salmonella, clostridium perfringens, c. difficile, potomac horses fever
why do an abdominal ultrasound on a horse with colitis?
assess colon wall thickness - especially right dorsal colon because it is associated with NSAID causes
why do abdominal radiographs on a horse with colitis?
look for sand
what may be seen on labwork from a horse with colitis?
dehydration, abnormal electrolytes, usually neutropenic, & hypoalbuminemic
what treatment is used for a horse with colitis?
biosecurity, supportive care (iv fluids), anti-endotoxemics & anti-inflammatories, antidiarrheals, & cryotherapy to prevent laminitis
T/F: for over 50% of colitis cases, there is no definitive diagnosis made
TRUE
what is colitis x?
idiopathic colitis - sometimes called antibiotic or stress associated
what antibiotics are used for certain causes of colitis?
oxytetracycline for potomac horse fever & metronidazole for clostridosis
what is the classic case presentation of a septic foal?
foal less than 14 days old with lethargy, decreased nursing, +/- obvious septic foci (joint effusion, omphalophlebitis, diarrhea, or pneumonia)
what is the goal standard for diagnosising sepsis in a foal? what is the disadvantage?
gold standard - takes 4-7 days to get results
how is sepsis diagnosed in a foal?
look for increased or decreased neutrophils with bands, increased lactate, ultrasound/radiography, & check blood IgG to assess for failure of passive transfer
how is sepsis treated in a foal?
broad spectrum antibiotics, IV fluids/plasma, anti-endotoxin therapies, nutritional support, lavage joints for septic joints, anti-diarrheals, & nebulization for pneumonia
T/F: for septic foals, the prognosis is good when treated at referral centers with aggressive therapy
TRUE
what must be done for all foals at 12-24 hours of age? why?
check all foals for adequate passive transfer at 12-24 hours of age!!! help to decrease the risk of sepsis!!!
T/F: gram negative pathogens are the most common bacterial causes of sepsis in foals
TRUE
T/F: foals will deteriorate rapidly, so any decrease in nursing or activity is an emergency
TRUE
