**8. Conclusion**

CTVT is the only naturally occurring contagious cancer in dogs. This oldest canine cancer spreads through the physical transfer of whole viable cancer cells between hosts. The specific host, transmission, gross lesion, microscopic features, growth pattern, immunologic relative host response, molecular characteristics, and responsiveness to treatment of CTVT are of interest to researchers and practitioners. Genital CTVT cases are visually noticeable and are easier to diagnose and treat than extragenital CTVT cases. The conventional single chemotherapeutic agent VCR has delivered curable treatment in most CTVT cases during 4–6 chemotherapeutic cycles. However, vincristine-resistant cases have been increasing in number. This decade has revealed more treatment options, such as VCR–LAP combination protocol. By contrasting the anatomical features of the two types of cases and the VCR-resistant cases, this paper highlights that the GTVT type is more noticeable and curable than the ETVT type.
