BOVINE EYE ENUCLEATION AND EXENTERATION

1. BOVINE EYE ENUCLEATION AND EXENTERATION Post-Operative Considerations

2. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS • Animals recovering from anesthesia may feel weak as the sedation may not completely wear off after the procedure and so it is important to ensure that the patients are slowly walked or carried to a safe, hazardless area. The best thing to do is to get an animal into a clean, shady, wide open space with minimal dust where there are no objects to trip over or bounce into. • The animal should be kept in a confined area for several days after surgery to allow for appropriate haemostasis to occur.

3. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS • An eye patch or covering may be worn by the patient until the eyelids have healed well (5-10 days post-operatively) to protect the surgery site and prevent self-trauma. It is usual for some orbital swelling to occur, usually due to hematoma formation underneath the sealed eyelids. This usually resolves in 3-5 days. The accumulation of blood into the suture-closed orbit acts as a pressure bandage and stops further bleeding.

4. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS Arrr. I’m Cap’nHugh Heifer.

5. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS • Alternatively, the wound could be packed with a lengthy strip of gauze/cloth, which is left protruding from sutured lids and each day a portion of the gauze/cloth is pulled out and subsequently removed. • Observe that this method which utilizes the exteriorization of material from the environment and into an open wound may act as a conduit for infection. The eye must therefore be observed daily and the patient examined.

6. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS • Warm compresses may be applied by the farmers if this seems to give the animal some relief. • A tear duct connects the orbit to the nares, and therefore a small amount of bleeding (usually serosanguinous in nature) from the ipsilateral nostril may be observed in the first 3-4 days after the procedure.

7. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS • Post-operative analgesia, in the form of NSAIDs such as Banamine, should be provided for approximately five days after surgery. • A short course of post-operative antibiotics like Pen-Strep are normally prescribed as it is impossible to maintain complete aseptic field throughout. • In the cases where non-absorbable sutures have been used in the eyelids, these are removed 10-14 days following surgery. Daily observation of the surgical site and assessment of general well being is performed until suture removal.

8. POST-OPERATIVE CARE FOR EYE ENUCLEATION AND EXENTERATION SURGERY IN COWS • Antiseptic, insecticide, and/or insect repellent preparations should be considered. • Animals are checked twice daily for 48 hours to detect any signs of sinusitis or skin bacterial contamination or fly strike.

9. POSSIBLE COMPLICATIONS ASSOCIATED WITH ENUCLEATION AND EXENTERATION • Cardiac bradyarrhythmia as a result of the oculo-cardiac reflex. Stimulation of the vagus nerve can be avoided or minimized by gentle globe and tissue handling. • Intra-operative bleeding- This may arise from the optic blood vessels. Usually packing the orbit with a swab and applying digital pressure long enough (five minutes or more) will stop the bleeding. Bleeding can also occur from the angularis oculi vein when the eyelids are being removed. It is situated below the medial canthus.

10. POSSIBLE COMPLICATIONS ASSOCIATED WITH ENUCLEATION AND EXENTERATION • Post-operative bleeding- Eyelid closure provides a seal to contain any further haemorrhage. However if bleeding is extensive, the orbit can swell and blood may escape. For small or unwell patients, the potential blood loss may be significant. • Infection • Dehiscence of the surgical wound

11. POSSIBLE COMPLICATIONS ASSOCIATED WITH ENUCLEATION AND EXENTERATION • Cyst or mucocoele formation due to inadequate resection of the conjunctiva or gland of the third eyelid. Build-up of lacrimal secretions can lead to sinus formation. • Orbital emphysema. • Blindness of the contralateral eye due to damage to the optic nerve • Pain- Severe pain warrants the attention of a veterinarian.

12. GENERAL COMMENTS • When it comes to enucleation in most animals, blindness is well tolerated. Animals with vision in one eye cope very well and generally behave completely normal. They do lose their binocular vision which does alter their depth perception (stereopsis), although they do retain a limited ability to judge depth using other visual cues. • In addition, a variable degree of orbital depression is present, but this is usually cosmetically acceptable and rarely causes the animal any problem. When the hair regrows, the depression becomes less obvious.

13. HAPPY MONO-COWCULAR (OCULAR) COWS “Mr. Take-way yuhgyul”

14. POST-OPERATIVE CARE FOR THIRD EYELID REMOVAL SURGERY IN COWS • Flush the eye with sterile solutions to remove blood and debris. • Apply an antibiotic ointment/eye drops • Shield the patient from wind, dust and bright sunlight for several hours to prevent keratitis • Consider postoperative analgesics.