Diseases Of The Bovine Eye Flashcards Preview

Diseases Of Cattle > Diseases Of The Bovine Eye > Flashcards

Flashcards in Diseases Of The Bovine Eye Deck (12)
Loading flashcards...
1
Q

Bovine infectious keratoconjunctivitis (Newforest Eye)

A

Moraxella bovis - spread by flies (near woodland) in summer
(Others mycoplasma, pneumonia viruses)

CS: lacrimation, blepharospasm, early keratitis (white spot), ulcers / keratitis, ulcers, pannus (vascularisation)

Tx: sub-conjunctival ampicillin, amoxicillin or oxytetracycline best

  • cloxacillin (local anaesthetic) BID so impractical
  • suture eyelid and 3rd eyelid - similar conditions
  • eye patches to relieve irritation

Good response to treatment

Control: 
Synthetic pyrethroid ear tags / pour ons, permethrin
Graze away from woodland
Ventilation and fly control indoors
Vaccination
2
Q

Bovine irisitis

A

Seen in the winter when feeding big bale silage
Listeria monocytogenes

Cs: early - patchy corneal opacity (multifocal unlike NF eye)
Glaucoma
White flecks in the anterior chamber
= uveitis

Tx: atropine - dilate pupil and reduce pain
Dexamethasone sub conjunctival

3
Q

How can you perform a sub conjunctival injection?

A

22g light blue needle

Inject into bulbar conjunctiva rather than the palpebral conjunctiva = better absorption

4
Q

Squamous cell carcinoma

A

Hereford
UV exposure
White faced animals are at a particular risk
Over 5 years old

Invasive - involves cornea, 3rd eyelid and conjunctiva
Tx- remove the eye
Poor prognosis

5
Q

Malignant catarrhal fever (secondary eye disease)

A

Ovine Herpes Virus
Contact with stressed sheep
Usually an isolated case

CS: systemically ill - differentiates from silage eye
Pyrexia - 41c
Encephalitis - depressed
Ulcerations of the oral mucosa 
Enlarged lymph nodes 
Respiratory signs
Diarrhoea 

OCULAR LESIONS: conjunctivitis, eyelid oedema, blepharospasm, corneal opacity (centripetal)
- early lesions start from the outside in, unlike NF eye which starts from the inside out

Euthanise the cow

6
Q

Infectious Bovine Rhinotracheitis (secondary)

A

Bovine herpes virus 1
Also causes respiratory disease and abortion

Dx: ELISA
Prev: vaccines

CS: Pyrexia, conjunctivitis and serous discharge, corneal oedema, nasal lesions and discharges

7
Q

Listeriosis (secondary)

A

Cs: dry eye keratitis due to facial paralysis (orbital fissure)
= unilateral facial paralysis - droopy ear
Weak jaw tone
Encephalitis - depressed and circling

Tx: high dose penicillin / oxytetracycline

8
Q

BVD cataracts

A

Infection between 75-150 days of pregnancy causes cataracts

May also cause cerebellar hypoplasia

9
Q

What eyes lesions might you see with systemic disease?

A

Septicaemia - hypopyon and petechiae
Endotoxaemia - injected conjunctiva (petechiae)
Post dystocia - petechiae
Dehydration - sunken
Bracken poisoning - hyphaemia (coagulopathy)

10
Q

CCN

A

Causes blindness
Most common neurological disease of calves

Due to a diet change on to a high energy diet - thiaminases are produced in the rumen

CS: early sign - star gazing, negative menace reflex, positive PLR, nystagmus, convulsions, opisthonotonus

Treatment- IV thiamine every 4 hours

Dx - PME

11
Q

Lead

A

Causes blindness

Seen at any age
Source - old car batteries, lead

CS: negative menace response, dilated pupils, tremors and convulsion
Dx: lead in the kidney
Tx: CaEDTA and xylazine

12
Q

Hypovitaminosis A

A

Causes blindness in calves
Fed on a roots and straw based diet
Increasingly seen in barley beef

CS: OEDEMA OF THE OPTIC DISC
night blindness , negative menace response, dilated pupils