Large Animal Ophthalmology Flashcards
What retrospective analysis can we do using Aqueous +/- Vitreous samples? (3)
- Calcium, magnesium
- Urea
- Beta hydroxybutyrate
What is this?
Hives/Photosensitisation
This facial swelling Is not bluetongue
Blain also has this effect
Treat symptomatically – CS/AH (BEWARE if pregnant)
Photosensitisation – like severe sunburn cause sloughing. Can be associated with liver disease and plants e.g. st jons wart
What is this?
Besnoitiosis – protozoa with severe skin effects
Reduces carcass value
Skin thicken
Transmissable
cystic like change (diagnostic)
What is this?
Infectious Bovine Rhinotracheitis (IBR)
What is the cause of Infectious Bovine Rhinotracheitis (IBR)?
- Infectious Bovine Rhinotracheitis (BHV-1)
- Affects upper respiratory tract and eyes
- MM around the eye are sites of replication
What are the signs of Infectious Bovine Rhinotracheitis (IBR)?
- May be pyrexic to start with as they are coming “down with it”
- Conjunctivitis: Hyperaemia and chemosis (oedema)
- Bilateral serous ocular discharge
- Diffuse corneal oedema possible too
- Immunoupressed – ulcer the eye and secondary bacterial infection
What is this?
Malignant Catarrhal Fever
What is the cause of Malignant Catarrhal Fever?
•Also herpes. Ovine herpes virus and the cow is the end host!
–Less group outbreaks
- Presents as individual animals
- The MCF viruses belong to the Rhadinovirus genus of the Gammaherpesvirinae subfamily of the Family Herpesviridae. The rhadinoviruses are lymphotropic herpesviruses that share a common genome structure and are consistently associated with lymphoproliferation.
What are the signs of Malignant Catarrhal Fever?
- Fever (104-107F)
- Nasal & ocular discharge
- Enlarged lymph nodes
- Uveitis: red eyes, corneal oedema & hypopyon
- Occasionally CNS signs
What is this?
“New Forest Disease” IBK
Infectious bovine keratoconjunctivitis
What is the cause of “New Forest Disease” IBK
Infectious bovine keratoconjunctivitis?
- Bacterial
- Moraxella bovis “New Forest Eye”
- Gram-negative, aerobic bacterium
- Found in the eyes of many recovered and apparently normal cattle
- Bacteria will attack cornea under circumstances!
- Associated with animals at pasture ad transmission by flies!
- Summer outbreak disease
- Initially might just be a small ulcer
How can we treat new forest disease?
–Topical Cloxacillin ointment
–Tetracycline (advisable as often 2º mycoplasma spp)
–Bulbar conjunctival injection
–NSAIDs
–No topical steroids (ulceration risk)
–Suture eyelids (pain control and reduces risk of perforation)
How can you prevent new forest disease?
Fly and pasture control
What is this?
“Silage Eye”/Bovine Iritis
What is the cause of “Silage Eye”/Bovine Iritis?
–May be associated with poor silage and a link to listeria
–Not fully understood
What is this?
Cataracts
What causes this, describe what is seen?
Hypovitaminosis A
Injury when moving round. Fed concentration ration and they calculated the wrong vitamin A! Swollen optic nerve
What is this?
“Pink Eye”
