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Summary

Between January 1978 and December 1988, 147 horses with ocular/adnexal squamous cell carcinoma (scc) were admitted to the Colorado State University Veterinary Teaching Hospital (CSU-VTH). Diagnosis was conjirmed by histologic examination of appropriate tissue specimens. Medical records and communication with owners, referring veterinarians, or both provided information regarding initial examination, treatment at the CSU-VTH, and final outcome. At initial examination, 123 (83.7%) horses had unilateral involvement and 24 (16.3%) horses had bilateral involvement. The nictitating membrane, nasal canthus, or both (28.1%); limbus (27.5%); and eyelid (22.8%) were most commonly affected. In addition to the ocular/adnexal location, scc was found elsewhere in 14 (9.5%) horses at initial examination. Adequate follow-up (≥ 4 months) for examination of tumor recurrence and survival analysis was obtained for 125 (85.0%) cases. After treatment at the CSU-VTH, tumor recurred in 30.4% of the cases. Tumor location, multiple vs single tumors at initial diagnosis, and CSU-VTH treatment modality influenced the recurrence of tumors. Survival analysis revealed a good prognosis for horses with ocular/adnexal scc. Although undefined, a conservative estimate of the median survival time was 47 months. Six factors (treatment prior to referral, tumor location, tumor size, single or multiple tumors, treatment modality at the CSU-VTH, and recurrence or nonrecurrence) were analyzed to determine their relation with survival. Treatment prior to referral, multiple vs single tumors at initial examination, and treatment modality used at the CSU-VTH did not influence survival. Tumor location influenced survival; scc involving the eyelid or orbit was associated with the poorest prognosis. Tumor stage (maximal dimension) was inversely related with survival. One or more recurrences of scc markedly reduced the likelihood of survival.

Free access
in Journal of the American Veterinary Medical Association

Summary

Proportional hospital accession ratios for equine ocular/adnexal squamous cell carcinoma (scc) were determined for 14 colleges of veterinary medicine participating in the Veterinary Medical Data Program between January 1978 and December 1986. Comparison of the ratios with their respective geographical, physical data has shown an increased prevalence of scc with an increase in longitude, altitude, or mean annual solar radiation. In contrast, prevalence of scc increased with a decrease in latitude.

Between January 1978 and December 1988, 147 horses with ocular/adnexal scc were admitted to the Colorado State University Veterinary Teaching Hospital. Diagnosis was confirmed by histologic examination of appropriate tissue specimens. Medical records provided information regarding month and year of admission and diagnosis, age at diagnosis, breed, gender, and hair color. Comparison with a randomly selected hospital control population revealed an increased prevalence of ocular/adnexal scc with an increase in age (P < 0.001). Compared with Quarter Horses, draft breeds (Belgian, Clydesdale, and Shire) and Appaloosas had a significantly (P < 0.001) greater prevalence of ocular/adnexal scc. Sexually intact males and females were significantly (P < 0.001) less likely (5 and 2 times, respectively) to have ocular/adnexal scc when compared with castrated males. The prevalence of ocular/adnexal scc was significantly greater for all hair colors when compared with bay, brown, or black (P < 0.01).

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Summary

Eighteen prolapses of the gland of the third eyelid in 17 Beagles were randomly allocated to 3 groups, which included nontreated (group 1, n = 6), excised (group 2, n = 4), and surgically repositioned (group 3, n = 8) glands. A Schirmer tear test (STT) was performed on affected and normal (control) eyes for 5 consecutive days on weeks 0 (baseline), 2, 4, 6, 8, 10, 12, 16, 18, 20, and 24. All prolapsed third eyelid glands were excised and examined histologically.

Ten female and 7 male Beagles were used in the prospective study. Mean age at prolapse was 35.1 weeks (range, 6 to 89 weeks). Control STT data revealed a population mean of 22.2 ± 2.1 mm/min. Complications developed in 4 of 6 eyes when the gland was allowed to remain in a prolapsed position. Complications for group-1 eyes were significantly (P < 0.005) greater than those for eyes in groups 2 and 3 (0 of 12). Comparison of affected and control eye baseline data revealed decreased STT values for eyes with prolapsed glands (P < 0.01). Mean differences between affected and control eyes were 2.2, 2.0, and 3.4 mm/min for groups 1, 2, and 3, respectively. A significant (P < 0.001) decrease in lacrimation (0.2 to 3.1 mm/min) in group-2 eyes was detected after removal of the gland. Tear production for affected eyes of nontreated dogs fluctuated above and below that of control eyes prior to excision of the prolapsed gland of the third eyelid; however, with time, affected and control eye STT values were not significantly different. Despite an increase in lacrimation after treatment of group-3 eyes, comparison of affected and control eye STT values revealed a persistent decrease in lacrimation (0 to 2.2 mm/min); however, reduction of lacrimation after surgical repositioning was less than that which resulted if the prolapsed gland of the third eyelid was excised (P < 0.02). Histologic changes in the gland of the third eyelid were mild, and significant differences were not detected among the 3 groups.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine risk factors for lens luxation and cataracts in captive pinnipeds in the United States and the Bahamas.

Design—Cross-sectional study.

Animals—111 pinnipeds (99 California sea lions [Zalophus californianus], 10 harbor seals [Phoca vitulina], and 2 walruses [Odobenus rosmarus]) from 9 facilities.

Procedures—Eyes of each pinniped were examined by a veterinary ophthalmologist for the presence of cataracts or lens luxations and photographed. Information detailing husbandry practices, history, and facilities was collected with a questionnaire, and descriptive statistical analyses were performed for continuous and categorical variables. Odds ratios and associated 95% confidence intervals were estimated from the final model.

Results—Risk factors for lens luxation, cataracts, or both included age ≥ 15 years, history of fighting, history of ocular disease, and insufficient access to shade.

Conclusions and Clinical Relevance—Diseases of the lens commonly affect captive pinnipeds. Access to UV-protective shade, early identification and medical management of ocular diseases, and prevention of fighting can limit the frequency or severity of lens-related disease in this population. An extended life span may result from captivity, but this also allows development of pathological changes associated with aging, including cataracts.

Full access
in Journal of the American Veterinary Medical Association