Squamous cell carcinoma in cattle, sheep and horse: study of 50 cases in south of Rio Grande do Sul

Abstract

Squamous cell carcinoma is a malignant tumour of keratinocytes. There are several factors associated with the development of squamous cell carcinoma, including prolonged exposure to ultraviolet light, lack of a pigmented skin, lack of hair or a very sparse hair coat at the affected sites. A retrospective study of squamous cell carcinoma from 1978 to 2002 in farm animals was made. The samples were obtained at the Regional Diagnostic Laboratory of the Veterinary School in Pelotas, Southern Brazil. The distribution of the neoplasm among the species was as follows: 30 in cattle, 7 in sheep and 13 in horses. Epidemiological data as breed, sex, age, and anatomical location of the tumors were statistically analyzed. The histological classification of the tumors graded from well differentiated to poorly differentiated. A multifactorial etiology of squamous cell carcinoma in farm animals is suggested although more retrospective and prospective studies are needed, to determine the role of each factor in the pathogenesis of the neoplasm.