Vol. 9, Special Issue 1, Part L (2025)

Canine Transmissible Venereal Tumor (CTVT) is a histiocytic tumor primarily affecting the external genitalia of dogs transmitted through copulation. It is typically localized to the genital area and rarely metastasizes. The present study was conducted on 30 female dogs that were presented for complaint of growth in vagina with bleeding in T.V.C.C, Mhow. The twelve female dogs out of thirty were categorized as chemotherapy by vincristine sulphate and cyclophosphamide. The biopsy samples of tumorous growth were collected for on the day before chemotherapy and after one week of chemotherapy or till regression for histopathological evaluation. Before chemotherapy most of the cells were in compact masses or sheet as cords, or loose in a delicate stroma. Regressing size of neoplasm demonstrated a decrease in number of tumour cells and their eventual disappearance along with oedema, haemorrhage and infiltration of neutrophils. Plasma cells fibrosis developed in the terminal stage of regression. In animals undergone therapy by vincristine sulphate the mean mast cell values at days 0 and 7^th got (p<0.01) significantly reduced, however the cyclophosphamide therapy mast cell variations were statistically non-significant.