Prevalence, Distribution and Factors Associated with the Presence and the Potential for Malignancy of Cutaneous Neoplasms in 174 Dogs Admitted to a Clinic in Northern Greece

One hundred and seventy-four dogs diagnosed with cutaneous neoplasms in the Animal Medical and Surgical Clinic, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, were studied. Thirty-one types of neoplasm were diagnosed, among which mast cell tumours (13.8%), hepatoid gland adenomas (9.8%), lipomas (5.7%) and histiocytomas (5.7%) were the most common. The prevalence of epithelial, mesenchymal, lymphohistiocytic and melanocytic tumours was 47.7, 40.8, 8.6 and 2.9%, respectively. Potentially malignant neoplasms were less frequently recorded than benign neoplasms. The tumours were single (80.5%) or multiple (19.5%) and located on the head and neck (18.4%), the body trunk (49.4%), the limbs (25.9%) or at multiple sites (6.3%). The factors evaluated in multivariable logistic regression models for possible association with the odds of a tumour's potential for malignancy included the age, the sex and the breed of the dog, as well as the histological type of the neoplasm. Dogs with mesenchymal tumours had two times higher odds of potential for malignancy than those with epithelial tumours. In contrast, dogs with either lymphohistiocytic or melanocytic tumours did not have increased risk of malignancy compared with dogs with epithelial tumours. The odds of tumour malignancy linearly increased with increasing age of the dog by a factor of 1.1 per year. Finally, the effect of the sex and the breed of the dog on the risk of developing cutaneous neoplasms was investigated in an age-matched case-control sample of 348 dogs by conditional logistic regression analysis. The odds of neoplasm presence were two times higher in pure bred dogs than in mongrels but did not differ between cross-breeds and mongrels.