Extra organs transmissible sensual tumour in a one-year-traditional German Shepherd male police dog owned by KERALA STATE K9 Squad was clinically investigated in addition to cytological and histopathological evaluation and successfully medicated with chemotherapeutic power vincristine sulphate. The dog was presented to Veterinary Clinics at Kerala Police Academy (KEPA), Thrissur District-while suffering 9-month training at State Dog Training School (SDTS-KEPA), accompanying the complaint of a bulging mass from the tip of tongue. On medical examination a firm nodular bulk of approximately 1-2 cm in width was seen raised from the tip of language on right side. The mass had a shift to bleed extensively when irritated. Impression smear was arranged from the tumour mass, staining accompanying Giemsa stain and examination under lubricate immersion revealed vicinity of neoplastic round to ovoid container population in addition to inflammatory cells mainly neutrophils. Diagnosis of Canine Transmissible Venereal Tumour (CTVT) was made. Treatment was begun with IV presidency of vincristine sulphate at dose rate of 0.025 mg/kg body pressure at weekly breaks initially (Six doses) and surplus (Six doses) at once in two week pauses. Complete regression happen only after 12 doses. Animal was given auxiliary medicines during the whole of therapy to underrate discomfort due to cytotoxic effect of drug as and when indicated by haematological anomalies and gastrointestinal disturbances.