Eye disease

• List the common eye diseases of cattle?

  IBK ( Infectious bovine keratoconjunctivitis)

  SCC ( Squamous cell carcinoma )

  Hypovitaminosis A

  PEM ( Polioencephelomalacia)

  Foreign body

  Colobomata
• Describe the restraint procedures for treatment of eye disease?

  Physical restraint

  • halters
  • nose grips
  • metal halter

  Chemical restraint (standing sedation)

  • xylazine
  • acepromazine
• Describe the pathophysiology of IBK?

  IBK occurs after corneal damage, where Moraxella bovis which is a gram negative coccobacillus that has pili that secretes cytolysin to adhere to and damage the cornea leading to corneal ulcer.
• Describe the diagnosis of IBK?

  Swab the eye and ocular secretions inoculated onto a culture media
• What are the tx of IBK?

  Cloxacillin 2 doses 72 hours apart

  Sub palpebral or bulbar injection of 2ml procaine pen and 1ml dexmethasone

  Oxytetracycline repeat in 3 days

  NSAID

  Eye patch

  Tarsorrhaphy
• What are the control methods for IBK?

  Flies

  Roll out hay

  Avoid overcrowding

  Remove affected animals

  Vaccine (Piligard) - 6 weeks before pinkeye season
• Describe SCC?

  Most common cattle tumour

  Hereford, simmental, friesen

  white face or non-pigmented eyes

  protruding eyes

  UV damage to epithelial cells
• What are the clinical signs of SCC?

  Starts as plaques, progress to growths, ultimately become invasive

  Blepharospasm

  Discharge

  Blindness
• What is the tx for SCC?

  Depend on severity,

  • surgical excision
  • Ionising radiation
  • Cryotherapy
  • Immunotherapy
• How to prevent SCC?

  Select for pigmented faces

  Early detection and treatment
• Outline the breed disposition for eye disease?

  Colobomata

  • inherited in Charolais cattle
• Hypovitaminosis A is due to?

  insufficient dietary supply of vitamin A or cattle on long-fed diet
• what are some signs of hypovitaminosis A in calves vs adults ?

  calves

  • tremors, anorexia, diarrhoea, dilated pupils
  • ataxia

  adults

  • night blindness
  • weight loss
  • infertility - RFM,
• How to diagnose hypovitaminosis A?

  vitamin A in serum or liver
• What are the ddx for hypovitaminosis A?

  Polioencephalomalacia

  Lead poisoning

  salt poisoning
• Common signs of lead poisoning?

  Cerebellar haemorrhage, ataxia, loss of menace, night blindness, weight loss
• What is the tx for lead poisoning?

  Give Ca-EDTA 200mg/kg bid for 4 days
• Why is Ca-EDTA given for lead poisoning?

  EDTA traps lead and other metals, forming a compound that the body can eliminate in the urine.
• Polioencephalomalacia is caused by?

  Thiamine deficiency
• What are the tx for PEM?

  IV thiamin 10-15mg/kg every 12 hours until symptoms disappear
• What are the prediposing factors for IBK?

  Age - young more than adult

  Time of the year - summer

  Environment - dust, feed particles

  Transport

  Mixing animals