CattleII- Ocular Diseases

  1. What is the most common neoplasm in cattle?
    ocular SCC
  2. Ocular SCC is associated with... (3)
    lack of pigmentation around eye, exposure to intense UV, increasing age
  3. What are the stages of ocular SCC?
    hyperplastic plaques--> regression OR papillomas--> non-invasive or invasive carcinoma
  4. What are the predilection sites for ocular SCC? (3)
    medial canthus/ 3rd eyelid, lateral limbus (border of sclera), lower lid
  5. It's important to remember that ocular SCC is...
    locally invasive but rarely metastatic
  6. What are the treatment options for ocular SCC? (6)
    enucleation/ exenteration, surgical excision, radiowave diathermy, beta radiation, immunotherapy, salvage
  7. What are anesthesia requirements for eye surgery? (3)
    peri-orbital anesthesia to globe an adnexa: motor to upper eyelid, local infiltration around bony orbit (sensory), and peterson block or retrobulbar block (motor)
  8. What is cause for condemnation with ocular SCC?
    extension to a peripheral lymph node, parotid ln.
  9. Where is lidocaine deposited for blockage of motor innervation to the upper lid?
    along the zygomatic arch
  10. What is the purpose of the peterson nerve block?
    desensitizes the muscles of the eye and globe
  11. What is the purpose of the retrobulbar block?
    should cause proptosis of the eye
  12. When is exteneration of the eye performed?
    removal of contents of the bony orbit (globe, muscles, connective tissue), usually due to SCC that extends deep into the orbit
  13. Why is it important to work quickly when performing exteneration of the eye?
    lots of bleeding! minimize blood loss
  14. When is high-frequency radiowave diathermy performed?
    small tumors (ocular SCC) [if you want to use it on a larger mass, debulk first]
  15. What is a surgical technique commonly used when there is SCC involvement of the lower eyelid?
    sliding H-plasty (kinda create a new eyelid of sorts)
  16. When a cow comes in with a proptosed eye, what are important differentials? (2)
    ocular SCC, retrobulbar lymphosarcoma (BLV)
  17. What is the etiology of infectious keratoconjunctivitis? What is transmission usually associated with?
    Moroxella bovis; face flies, dust, sunlight
  18. Moroxella bovis exists in two forms, which are __(2)__, but the _______ form causes ________.
    piliated and non-piliated; piliated; corneal ulcers
  19. Clinical signs of pinkeye. (7)
    blepharospasm, photophobia, lacrimation, ulceration, corneal edema, resolution or perforation may result
  20. What is treatment for pinkeye? (5)
    • systemic oxytet and tulithromycin
    • subconjunctival injection +/- steroid
    • temporary third eyelid flap
    • vaccination
    • fly control
Card Set
CattleII- Ocular Diseases
vetmed cattleii