Vet Column 7-26-10
Fort Collins, Colo.
Enucleation is a veterinary medical term for removal of the eye. Regardless of the species, enucleation is not something that animal owners and veterinarians prefer, but in some situations, a choice. When the elective option is made to remove an eye of cattle, it is generally based upon a projected outcome. Kansas State University veterinarians recently published a summary of case reviews from their veterinary teaching hospital following this elective procedure.
From January 1, 1998 through December 31, 2006, the veterinary teaching hospital at Kansas State University removed an eye from 53 cattle. Of these, 30 (57 percent) were Herefords; eight (15 percent) were Angus; six (11 percent) were crossbred; four (8 percent) were Simmental; two (4 percent) were Holstein; one (2 percent) were Gelbvieh; and two (4 percent) were of unspecified breed composition. Of these, 42 (79 percent) were cows; three (6 percent) were bulls; and eight (15 percent) were of unspecified gender as noted on the veterinary medical record.
Ocular diseases justifying the enucleation included ocular sqamous cell carcinoma (cancer eye) in 45 (85 percent) of the cases; lymphosarcoma (another type of cancer located behind the eye) in two (4 percent) cases; undue prominence of the globe of the eye beyond the eyelid (proptosis) in four (8 percent) of the cases; actual rupture of the eye in one (2 percent) of the cases; and an unspecified diagnosis in one (2 percent) of the cases. Of the 53 cases, 52 of the enucleations were performed with the animal standing in a squeeze chute. Most were haul in type circumstances with 47 (89 percent) returning to the farm or ranch the same day of the surgery.
All patients received local anesthesia (nerve blocks around or behind the eye) with 19 (36 percent) of the cattle receiving additional sedation with various additional systemic agents. Systemic antibiotics were used in 35 (66 percent) of the cattle. The various antibiotics used included oxytetracycline in 35 (66 percent) of the cattle; penicillin in 10 (29 percent) of the cases; and florfenicol in one (3 percent) animal. Prior to surgical closure, cephapirin mastitis tube ointment was placed into the orbit in six (11 percent) animals and dissolved or intact sulphonamide oral boluses were placed into the orbit of three (6 percent) of the cases. Banamine was used postoperatively in nine (17 percent) of the 53 cattle.
Of the 53 cattle, 10 (19 percent) developed an infection in the eye socket during the 21 days following surgery. Most were evaluated at suture removal 14 to 21 days post-operatively. Affected cattle were treated by suture removal, wound lavage, and administration of systemic antibiotics in selected cases.
Telephone interviews were conducted with the owners of the cattle an average of 44 months (range of 2-108 months) following surgery. Long-term follow-up information was obtained on 22 of the 53 cattle. Of the 22 cattle that had long-term follow-up, 15 (68 percent) healed with no further complications. One of the animals with cancer eye as the precipitating cause for performing the enucleation, developed a recurrence of the lesion approximately 3 years later and was culled from the herd.
These data support that choosing the treatment of option of removing an eye of cattle can be associated with a high rate of successful outcomes. It has the potential to resolve chronic pain, infection, and cancerous disease. Although post-operative infection of the operative site is common, most cases require minimal medical therapy.