Diseases of the bovine eye

Question 1

Name three primary diseases of the bovine eye

Answer 1

• Infectious bovine keratoconjunctivitis
• Bovine iritis
• Squamous cell carcinoma

Question 2

Infectious bovine kerato-conjunctivitis is also known as?

Answer 2

New forest eye

Question 3

Bovine iritis is also known as?

Answer 3

Silage eye

Question 4

Name the causative agent of new forest eye

Answer 4

Morexella bovis

Question 5

List the clinical signs of New forest eye

Answer 5

Lachrymation
Blepharospasm
Early keratitis - white spot
Ulcer
Pannus – vascularisation

Question 6

How is new forest eye treated?

Answer 6

1. LA eye ointment - Cloxacillin
2. Sub-conjunctival injection - oxytetracycline, amoxicillin
3. 3rd eyelid suture or eyelid suture
4. Eye patches

Question 7

List the risk factors for new forest eye

Answer 7

Flies
Woodland
Dust
Chaff
UV light
“virus pneumonia.”

Question 8

How can new forest eye be prevented?

Answer 8

1. Fly control - ear tags, pour-on, permethrins.
2. Graze away from fly habitat (woodland).
3. Ventilation & fly control inside.

Question 9

Bovine iritis is associated with?

Answer 9

Big bale silage feeding
Winter

Question 10

List the clinical signs of bovine iritis

Answer 10

• Early cases = constricted pupil
• Patchy or multiple areas of corneal opacity
• Glaucoma
• White flocules in anterior chamber
• Later = vascularisation (inside surface of cornea).
• “signs are on inside of cornea.”
• Negative to fluorescin

Question 11

How is bovine iritis treated?

Answer 11

Antibiotics alone ineffective
Sub-conjunctival (bulbar) injection of:
- atropine (mydriatic) 0.3-0.6 mg ( 0.5-1 ml)
- dexamethasone 1 - 3 mg (0.5-1.5 ml)
± antibiotic

Question 12

Which breed is predisposed to SCC?

Answer 12

Herefords

Question 13

Which structures of the eye are most commonly involved in SCC?

Answer 13

Cornea
Third eyelid
Conjunctiva

Question 14

List the general clinical signs of malignant catarrhal fever

Answer 14

• Persistent pyrexia 41C
• Depressed - encephalitis
• Nasal & mouth erosions
• Lymph nodes enlarged
• Respiratory signs
• Diarrhoea

Question 15

List the eye lesions seen in malignant catarrhal fever

Answer 15

Conjunctivitis
Eyelid oedema
Blepharospasm
Corneal opacity - centripetal

Question 16

List the clinical signs of IBR

Answer 16

• Pyrexia 41oC
• Conjunctivitis & serous discharge
• Corneal oedema
• Nasal lesions & discharge
• Severe milk drop

Question 17

How does listeria lead to eye issues?

Answer 17

Facial paralysis -> dry eye keratitis due to a lack of blink reflex

Question 18

How is listeria treated?

Answer 18

Oxytetracycline or penicillins
65% Recovery rate

Question 19

Cataracts is associated with which disease?

Answer 19

BVD

Question 20

Which toxicity presents with blood in the anterior chamber?

Answer 20

Bracken poisoning

Question 21

List some causes of blindness

Answer 21

Cerebrocortical necrosis
Lead poisoning
Vitamin A deficiency

Question 22

What is the cause of Cerebrocortical necrosis?

Answer 22

Thiamine/Vitamin B1 deficiency

Question 23

How is CCN diagnosed?

Answer 23

PME
Brain fluoresces under UV light

Question 24

What are the clinical signs of CCN?

Answer 24

• Early cases - star gazing
• -ve menace test - blind
• +ve pupillary response to light
• Nystagmus & convulsions
• Opistothonus

Question 25

How can CCN be treated?

Answer 25

IV thiamine 5-10 mg/Kg - every 3-4 hours.

Question 26

What are the clinical signs of lead poisoning?

Answer 26

-ve menace test
Dilated pupils
Tremors & convulsions

Question 27

How is lead poisoning treated?

Answer 27

Sodium Calcium Edetate (EDTA) iv & sedation

Question 28

What are the clinical signs of vitamin A deficiency?

Answer 28

Night blindness
-ve menace test
Dilated pupils
Oedema of optic disk