Opthalmology (Farm) Flashcards
What nerve block should be used to examine the bovine eye?
Auriculopalpebral
What is the correct term for new forest eye?
Infectious Bovine Keratoconjunctivitis
What is the correct term for silage eye?
Bovine iritis
What is the most common ocular tumour in cows?
Squamous Cell Carcinoma
What causes new forest eye?
Morexella Bovis
How is IBK treated?
LA cloxacillin ointment
Sub-conjunctival injection - oxytet/ampicillin
Suture 3rd eyelid
What are the risk factors for IBK?
flies woodland dust chaff UV light Viral pneumonia
how can we prevent IBK?
Fly control (ear tag/pour on) Ventilation and fly control inside
When does silage eye occur?
Winter
What are the clinical signs of silage eye?
Constricted pupil (early) Patchy opacity Glaucoma Anterior chamber flocules Corneal Vasc (late)
Compare the fluorescin staining of IBK and silage eye.
IBK +ve
Silage eye -ve
which pathogen is associated with silage eye?
Listeria
How is bovine iritis treated?
bulbar subconjunctival injection of atropine+dex+AB
Which breed of cow is predisposed to ocular SCC?
herefords
What age do cows present with SCC?
> 5yo
How are SCCs treated?
Surgical Removal - may recur
Which nerve block(s) should be used for an enucleation?
Retrobulbar
Petersen block
What is the issue with enucleation in cows?
prey animal - can be scared more easily and therefore dangerous
Which pathogen causes malignant catarrhal fever? (MCF)
Ovine Herpesvirus 2
What are the clinical signs of MCF?
Pyrexia (>41) Depressed Nasal/mouth erosions LN enlarge Resp signs Eye signs
What are the ocular signs of MCF?
conjunctivitis, eyelid oedema, blepharospasm, opacity
What is the prognosis for MCF?
Hopeless - fatal Dz
Which virus causes IBR?
BHV1
How is IBR diagnosed?
ELISA
IF from swab
How can IBR be prevented?
Vaccines (marker!)
What are the clinical signs of IBR?
Pyrexia >41 Conjunctivitis Serous Discharge Corneal oeema Nasal lesion/disch SEVERE milk drop
What are the signs of listeriosis?
Encephalitis, circling Dz
Unilateral facial paralysis
Depression
How is listeriosis treated?
Oxytet or penicillin
Which generalised Dz leads to cataracts?
BVD
Ingestion of what may cause Hyphaema?
Bracken
How is CCN diagnosed?
PME - brain fluoresces under UV
What causes CCN?
Vitamin B1 deficiency
What are the signs of CCN?
Star gazing -ve menace (blind) \+ve PLR Nystagmus Convulsions Opisthotonus
How should bovine CCN be treated?
Thiamine q3h IV
How does lead poisoning present?
-ve menace
miosis
tremor/convulsion
How is Lead poisoning treated?
IV EDTA
Sedation
Magneisum 5%
4 equal doses 2-5d
How is lead poisoning diagnosed?
Pb in kidney and history
what are the clinical signs of vitamin A deficiency?
Night blindness
-ve menace
dilated pupils
Optic disc oedema
What causes Vit a deficiency?
Growing cattle indoors
Root and straw diet
