Final Exam - Food Animal Ophthalmology Flashcards
if you see scleral infection present in a very sick cow, what should you be thinking about?
sepsis is suspected
what lesion is shown here? what is it associated with?
episcleral hemorrhage - secondary to calving trauma
what congenital lesion is shown here?
dermoid
what are some teratogens that cause congenital ocular lesions in cattle?
BVD
blue tongue virus
veratrum californicum
what congenital ocular lesions are seen with BVD?
blindness, cataracts, nystagmus, microphthalmos, corneal lesions, etc
what congenital ocular lesions are seen with blue tongue virus?
blindness, chorioretinitis, & retinal dysplasia
what congenital ocular lesions are seen with veratrum californicum?
anophthalmia, cyclopia, & synophthalmos
what congenital lesion is shown here? what clinical signs are associated with it? what animals are commonly affected by it?
entropion - skin/hairs irritate the eye, usually from the lower lid
squinting, tearing, ulceration, & blindness
common in sheep - genetic condition (no breeding) or congenital/early onset
what are some other names for infectious bovine keratoconjunctivitis?
pinkeye & IBK
what lesion is shown in the photo? what causes it?
infectious bovine keratoconjunctivitis
moraxella bovis - gram negative coccobacillus that contains hemolysin, necrotizing factor, & leukocidin
can also be caused by other moraxella spp, mycoplasma spp, & respiratory viruses
how is infectious bovine keratoconjunctivitis spread?
shed in nasal & ocular secretions - direct contact, aerosols, fomites, mechanical vectors, introduction of new animals, & recent infections
highly infectious!!!
what animals are severely affected by infectious bovine keratoconjunctivitis?
high morbidity in 3-12 month old calves/immunologically naive
beef cattle more susceptible than dairy!!!
how does IBK affect economics?
decreased yield (less weight gain, decreased milk yield, lower calf value), cost of treatment, & sale loss of damaged eyes!
what is the pathophysiology of infectious bovine keratoconjunctivitis?
corneal damage -> epiphora -> flies -> spread of disease!!!!!
pili bind to the cornea & the enzyme allows entrance to the stroma -> corneal perforation
what clinical signs are seen in early disease of infectious bovine keratoconjunctivitis?
lacrimation, blepharospasm, photophobia, & conjunctival hyperemia
what clinical signs are seen in midstage disease of infectious bovine keratoconjunctivitis?
central ulceration & uveitis
what clinical signs are seen in late disease of infectious bovine keratoconjunctivitis?
vessel invasion, necrosis of the stroma, & granulation of the corneal defect
what sequelae are associated with infectious bovine keratoconjunctivitis?
corneal scarring, corneal perforation, glaucoma, & phthisis bulbi
how is infectious bovine keratoconjunctivitis diagnosed?
history, signalment, ocular exam
culture for moraxella
PCR for IBR & mycoplasma
what treatment is used for infectious bovine keratoconjunctivitis?
decrease exposure - eye patch, 3rd eyelid flap
injectables - antibiotics & NSAIDS
topicals - abx, atropine, & steroids
subconjunctival injections - bulbar or palpebral
how is infectious bovine keratoconjunctivitis controlled/prevented?
must control the spread of disease!!!!!
fly control, shade, mow pastures, dust/pollen control, & vaccines
what causes keratoconjunctivitis in sheep/goats? what treatment is used?
similar to cattle
mycoplasma conjunctivae, chlamydia psittaci, branhamella ovis, & coxiella burnetti
same as cattle for treatment but no vaccine available!
what is exenteration? when is it done?
removal of all contents in the orbit - done for extensive lesions
use the auriculopalpebral block, retrobulbar block, & maybe peterson eye block
what lesion is shown here?
ocular squamous cell carcinoma
