Canine transmissible venereal tumour: a review

Abstract

Canine transmissible venereal tumour (CTVT) is a contagious venereal tumour of dogs, commonly observed in dogs that are in close contact with one another, or in stray and wild dogs that exhibit unrestrained sexual activity. CTVT represents a unique, naturally transmissible, contagious tumour, where the mutated tumour cell itself is the causative agent and perpetuates as a parasitic allograft in the host. Clinical history, signalment and cytological features are often obvious for establishing a diagnosis though biopsy and histological examination may be needed in atypical cases. Most cases are curable with three intravenous injections of vincristine sulphate at weekly intervals. The role of stray and wild dogs makes the disease difficult to control and necessitates sustained animal birth control in stray dogs along with prompt therapy of the affected dogs. This review captures the manifold developments in different areas embracing this fascinating tumour, including its biology, diagnosis and therapeutic alternatives.

Nasal and Ocular Forms of Transmissible Venereal Tumor in Dogs

“…Metastasis is uncommon (5%); when it occurs, it is usually to the regional lymph nodes including inguinal and external iliac lymph nodes but may also be seen in the kidney, spleen, liver, eye, tonsils, brain, pituitary, skin and subcutis, maxillary bone, mesenteric lymph nodes and peritoneum (Ganguly, 2016).…”

“…Canine transmissible venereal tumor (CTVT) is a round cell neoplasm of dogs and other canids in region particular to tropical and sub-tropical climate (Ganguly, 2016) which has high tendency to bleed from the nearest cavity. The CTVT is common in stray dogs, due to uncontrolled breeding behavior but is also reported in neutered and intact house dogs (Albanese et al, 2002, Strakova andMurchison, 2014).…”

Immunocytochemical characterization of primary cell culture in canine transmissible venereal tumor

“…The transference of TVT among dogs has been found to be equal, regardless gender, either by implantation of viable tumor cells in mucous membranes during coitus, or by scratching, licking, biting or smelling of a carrier animal (Varaschin et al 2001, Ganguly et al 2013, Sreekumar et al 2015. Besides genital contact, TVT also may have an extra-genital localization (Pereira et al 2000, Rodrigues et al 2001, Albanese et al 2002, Siddle & Kaufman 2013.…”

“…The tumor has a unique behavior showed by the usual occurrence of spontaneous regression in adults. However, in newborns and immunocompromised dogs, it becomes metastatic and, consequently, fatal (Cohen 1973, Yang & Jones 1973, Ganguly et al 2013.…”

“…Besides genital contact, TVT also may have an extra-genital localization (Pereira et al 2000, Rodrigues et al 2001, Albanese et al 2002, Siddle & Kaufman 2013. TVT usually is restricted to the points of origin and implantation of the disease, except in rare cases, around 2.5% (Pandey et al 1989), in which it invades adjacent tissues, lymphatic and/or blood circulation, and reaches distant areas such as lungs, liver, spleen, brain and other organs as metastatic deposits (Meuten 2002, Maxie 2007, Ganguly et al 2013, Strakova & Murchison 2014.…”