Copper and zinc concentration in skin neoplastic tissues in dogs

Zinc and copper concentrations were assessed in skin tumours and serum of 26 dogs of different breeds. The analysed tumours were situated on legs, chest, and abdomen, 8, 7, and 5 cases, respectively. In 2 cases, the tumours were situated on the tail, anal region, and head. On the basis of a histopathological examination, 17 tumours were classified as malignant, while 9 were classified as benign ones. The dogs age-matched to those with neoplastic changes belonged to the control group. However, they were subjected to surgery due to reasons other than tumours. Samples of skin with subcutaneous tissue and serum obtained from these animals were handled in an identical procedure to those of the other groups. The spectrophotometric atomic absorption method and PAY-UNICAM apparatus were used to determine zinc and copper concentrations. It was demonstrated that the concentration of zinc and copper in malignant tumours was significantly increased in relation to the tissues obtained from healthy animals. Furthermore, tissue concentration of copper in benign tumours was significantly increased in comparison to the controls. In conclusion, the determination of zinc and copper concentrations in malignant neoplastic tissues and serum of dogs may be used as an additional diagnostic indicator conforming histopathological examination of tumour malignancy.