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28 Cards in this Set
- Front
- Back
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What are 2 financially important ocular diseases of ruminants?
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ocular SCC (“cancer eye”): a leading cause of carcass condemnation (17%)
infectious bovine keratoconjunctivitis (IBK; pink eye): losses of $200M/yr |
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What are some diseases of the eyelids?
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trauma
blepharitis entropion |
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entropion in small ruminants
a. signalment b. signs c. pathogenesis d. tx |
a. neonatal sheep & goats (2-3 d.)
b. bilateral, lower lids: serous epiphora, mucopurulent d/c, corneal ulcer c. 2º to illness --> dehydration --> enophthalmos d. temporary tacking suture (~2 wks) |
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What are ddx for "googly eyed" cattle?
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strabismus
exophthalmos buhthalmos: enlarged globe |
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What are some congenital & acquired causes of strabismus?
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congenital: bilateral convergent strabismus w/ exophthamia (BCSE)
acquired: listeriosis, polioencephalomalacia |
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What are some causes of exophthalmos?
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retrobulbar lesions: usually unilateral strabismus/exophthalmos
ddx: orbital cellulitis, neoplasia |
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orbital cellulitis --> exophthalmos
a. etiology b. signs |
a. puncture wounds, FB, chronic frontal sinusitis, Actinobacillus
b. SUDDEN ONSET, febrile, leukocytosis, TM pain, anorexia (d/t PAIN), blepharoedema, chemosis, exposure keratitis |
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neoplasia --> exopthalmos
a. etiology b. signs c. dx |
a. LSA (#1), lymphangiosarcoma, SCC, adenocarcinoma
b. SLOW PROGRESSION, NON-PAINFUL w/ LSA: lymphadenopathy, cardiac arrhythmia, melena c. aspiration, bx |
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What are some causes of blepharitis?
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-infectious
-allergic -neoplastic: SCC, melanoma, fibroma, FSA, papilloma -photosensitization: sloughing of eyelid tissue |
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What is the main cause of buphthalmos?
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glaucoma
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glaucoma
a. signs w/ primary (congenital) b. causes of secondary b. signs w/ secondary |
a. NON-PAINFUL, ENLARGED GLOBES, MINIMAL EPISCLERAL INJECTION, MILD CORNEAL EDEMA
b. uveitis, neoplasia (ex. LSA) c. PAINFUL, SEVERE EPISCLERAL INJECTION, MILD TO SEVERE CORNEAL EDEMA both can have corneal vascularization, corneal striae, poorly responsive pupil, lens subluxation/luxation, fundus abnormalities |
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What are ddx for red &/or cloudy eyes?
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conjunctivitis: red
keratitis: red & cloudy uveitis: red & cloudy |
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What are some common causes of keratoconjunctivitis?
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a. INFECTIOUS DZ COMMON: IBR, IBK, pasteurellosis, mycoplasmosis, chlamydiosis
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Chlamydia/Mycoplasma keratoconjunctivitis
a. signalment b. clinical signs c. ddx d. dx |
a. mainly sheep & goats
b. conjunctivitis, d/c, petechial hemorrhage, conjunctival lymphoid follicles, usually bilateral, severe keratitis (advanced cases) c. IBK, IBR (goats) d. clinical signs, conjunctival scrapings (round, oval, or triangular cytoplasmic inclusion body) -usually don’t do diagnostics if acute -Chlamydia & Mycoplasma look same & are treated same way (SYSTEMIC & TOPICAL TETRACYCLINE) |
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infectious bovine keratoconjunctivitis (IBK)
a. species affected b. etiology c. contributing factors |
a. cattle, sheep, goats
b. Moraxella bovis c. UV light, face flies, environmental irritants, concurrent infection (Mycoplasma, IBR), non-pigmented skin around eyes |
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infectious bovine keratoconjunctivitis (IBK)
a. transmission b. pathophysiology c. clinical signs |
a. direct contact #1 (nasal & ocular d/c), mechanical vectors (face fly, house fly, barn fly)
b. capsular pili adhere to corneal surface -direct cytotoxicity of organism on epithelial cells c. CONJUNCTIVITIS & ULCERATIVE KERATITIS, d/c, blepharospasm -cornea: edema (focal axial to diffuse), cellular infiltrate, ulceration, vascularization, perforation, fibrosis (scarring) -healing --> corneal scarring in most cases -possible blindness: glaucoma, panophthalmitis, perforation -2º uveitis: photophobia, miosis, aqueous flare |
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infectious bovine keratoconjunctivitis (IBK)
a. ddx b. dx |
a. infectious conjunctivitis: IBR, Mycoplasma, Chlamydia
-CORNEAL ULCERATION in IBK clinically differentiates it from IBR -uveitis: malignant catarrhal fever, immune-mediated -other: thelaziasis, ocular FB, corneal granulation tissue, photosensitization, SCC b. presumptive: seasonal occurrence, clinical signs, high incidence of ocular dz in young animals -definitive: positive bacterial culture & ID (collect from corneal ulcer) |
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infectious bovine keratoconjunctivitis (IBK)
a. tx b. prevention |
a. PARENTERAL FLORFENICOL OR OXYTET: may not improve clinical dz or eradicate carrier state, but may ↓ severity
-hard to maintain therapeutic levels in tear film: economic & practical considerations -pain relief: topical atropine, topical & oral NSAIDs -protection of cornea: temporary tarrsorrhaphy & nictitans flaps b. isolate affected cattle, protect from sunlight, remove carriers, control vectors vaccination: limited protection from clinical dz -herds vaccinated w/ MLV IBR are at ↑ risk for IBK -passive immunity: calves show ↓ incidence/severity |
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infectious bovine rhinotracheitis (IBR)
a. species affected b. etiology c. signs |
a. cattle, goats
b. herpesvirus c. conjunctivitis as 1º manifestation: 2 wk. course -unilateral or bilateral +/- non-ulcerative keratitis & 2º uveitis -mucosal epithelial necrosis & lymphocytic infiltrate: raised red/white plaques "RED NOSE": classic for IBR + resp. or repro forms of dz: rhinotracheitis, infectious pustular vulvovaginitis, abortion |
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What is the preferred tx for infectious keratoconjunctivitis?
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ID underlying cause
local vs. systemic dz topical ABs: labor intensive Chlamydia & Mycoplasma: topical & systemic tetracycline |
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"cancer eye": SCC
a. species affected b. incidence increases w/... c. tx |
a. cattle, rarely sheep & goats
b. age, altitude, inc. hours in sunlight, lack of pigmentation c. curative or cytoreductive sx: depends on location -nictitans removal, keratectomy, enucleation, etc. adjunctive: cryotherapy, hyperthermia, immunotherapy, radiation, chemo last resort: enucleation |
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What are some etiologies of chorioretinitis?
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BVD (#1), neonatal septicemia, TME, rabies, toxoplasmosis, tuberculosis, listeriosis, aspergillosis, scrapie
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What are some ocular manifestations of BVD?
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microphthalmia, cataract, retinitis, retinal atrophy or detachment, optic neuritis
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What are some causes of blindness?
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hypovitaminosis A
retinal degeneration optic neuritis cortical blindness |
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How does hypovitaminosis A result in blindness?
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maternal vitamin A deficiency --> retinal dysplasia
vitamin A deficiency --> papillaedema (optic n. swelling), blindness |
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What are some etiologies of retinal degeneration --> blindness?
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bracken fern poisoning: sheep “bright blindness”
locoweed poisoning hereditary retinal degeneration: cattle, Toggenburg goats |
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What are some etiologies of optic neuritis --> blindness?
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male fern intoxication: cattle
blind grass intoxication: sheep & goats infectious dz: BVD |
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What are some cortical causes of blindness?
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lead poisoning
ketosis (reversible) polioencephalomalacia scrapie |
