Ophth - bovine Flashcards
What are the 3 most common eye conditions in farm animals?
Infectious bovine keratoconjunctivitis (New forest eye)
Listeria
Infectious ovine keratoconjunctivitis (pink eye)
What is the alternative name for Infectious bovine keratoconjunctivitis?
New forest eye
What causes Infectious bovine keratoconjunctivitis (new forest eye)?
Moraxella bovis - gram negative bacillus
How is Infectious bovine keratoconjunctivitis (new forest eye) spread?
Flies
What increases the pathogenicity of Infectious bovine keratoconjunctivitis (new forest eye)?
UV light
What changes to the eye does Infectious bovine keratoconjunctivitis (new forest eye) cause?
Ulcerative keratitis - central
Cellular infiltrate and vascularisation
Descemetocoele
Corneal rupture
Blindness
What clinical signs does Infectious bovine keratoconjunctivitis (new forest eye) cause?
Ocular pain - blepharospasm, lacrimation etc.
Dullness, inappetant
How do you treat Infectious bovine keratoconjunctivitis (new forest eye)?
Topical antibiotics
Long acting systemic antibiotics
NSAIDs
What is the prognosis of Infectious bovine keratoconjunctivitis (new forest eye)?
3-4 weeks
May leave a scar
What is another name for listeriosis in the eye?
Silage eye
What causes listeriosis (silage eye)?
Gram positive bacteria - listeria monocytogenes
Found in silage if the silage isnt acidic enough/has soil in it
How does the listeria pathogen reach the eye?
Infects through excoriations in the mouth
Tracks up the trigeminal nerve to eye
Or straight into eye
What are the clinical signs of listeriosis (silage eye)?
Uveitis
Keratitis
NO ULCER
How is listeriosis (silage eye) different to new forest eye?
No ulcer
How do you treat listeriosis (silage eye)?
Systemic antibiotics - penicillin or tetracyclines
Steroids - dexamethasone
What other diseases can cause uveitis in cows?
Malignant catarrhal fever
Infectious bovine rhinotracheitis
What causes infectious ovine keratoconjunctivitis (pink eye)?
Mycoplasma conjunctivae and chlamydophila psittaci ovis
What are the risk factors for infectious ovine keratoconjunctivitis (pink eye)?
High stocking density
High UV light
Carrier animals
What are the clinical signs of infectious ovine keratoconjunctivitis (pink eye)?
Ocular pain - blepharospasm
Initially unilateral then bilateral
Ocular mucopurulent discharge
Corneal vascularisation
Corneal oedema
How do you treat infectious ovine keratoconjunctivitis (pink eye)?
Tetracyclines - will treat but remain carriers
No topical treatment
What species of farm animal get ocular neoplasia the most?
Cows - more than sheep
What is the most common ocular neoplasia in farm animals?
Squamous cell carcinoma
What breed of cow gets squamous cell carcinomas on the eye the most?
Herefords - white faces
Where do ocular neoplasms tend to metastasise to?
Parotid lymph node
How do you treat ocular neoplasms?
Enucleation
What can cause congenital cataracts?
Bovine viral diarrhoea
What can cause cataracts as a secondary condition?
Uveitis
Trauma
What can cause blindness in farm animals?
Meningoencephalitis
Pregnancy toxaemia
Lead poisoning
Hydatid disease in sheep
What do you use to identify an ulcer in a cow?
Fluoresceine
