Infective venereal tumours in dogs

The cancer which survived: insights from the genome of an 11000 year-old cancer

“…This, however, contrasts with naturally occurring CTVT, where spontaneous regression has not been consistently reported [14,47,48]. The immune response to CTVT may be influenced by the site of tumour transplantation (experimentally transplanted CTVT tumours are usually injected subcutaneously) and the concurrent presence of injuries and inflammation.…”

Clonally transmissible cancers in dogs and Tasmanian devils

“…Canine transmissible venereal tumor is spread by coitus, and can be transferred either from male to female or female to male (Bellingham Smith and Washbourn, 1898;Powell White, 1902). It can also be spread by licking, sniffing or scratching of affected areas; thus CTVT can sometimes develop extragenitally, either with or without genital involvement (Nowinsky, 1876;Feldman, 1929;Higgins, 1966;Ndiritu et al, 1977;Brown et al, 1980).…”

“…Male dogs, which are constantly sexually receptive, may have greater opportunity to spread CTVT, in contrast to females, which become sexually receptive only once every 6-7 months. Indeed Bellingham Smith and Washbourn (1898) observed that a single CTVT-affected male dog spread the disease to 11 of 12 females, and at least in some regions CTVT is naturally found with greater prevalence in females than in males (Karlson and Mann, 1952;Dass and Sahay, 1989;Scarpelli et al, 2008). If CTVT tumors in males become sufficiently large, they may obstruct preputial retraction (Wade, 1908;Mello Martins et al, 2005).…”

“…Experimental transfer of CTVT into immunocompromised individuals, such as neonatal puppies (Yang and Jones, 1973) or X-irradiated dogs (Cohen, 1973), results in continued progression of CTVT and widespread metastatic disease. Conversely, dogs that have recovered from CTVT have serum-transferable immunity to re-infection (Bellingham Smith and Washbourn, 1898;Crile and Beebe, 1908;Powers, 1968) and puppies born to mothers that have been exposed to CTVT are less susceptible to the disease (Yang and Jones, 1973). The transition from progressive to regressive phases of CTVT growth is accompanied by a marked increase in immune cell infiltration (Wade, 1908;Chandler and Yang, 1981;Hill et al, 1984;Trail and Yang, 1985;Perez et al, 1998;Barber and Yang, 1999;Gonzalez et al, 2000;Chu et al, 2001a;Hsiao et al, 2002;Mukaratirwa et al, 2004Mukaratirwa et al, , 2006.…”

“…However, despite 130 years of research into CTVT, many features of this unusual transmissible cancer remain poorly understood. Canine transmissible venereal tumors first appear as small, firm, localized nodules, typically at the base of the glans penis in males, or in the vaginal vestibulum of females (Bellingham Smith and Washbourn, 1898;Rust, 1949;Kimeto and Mugera, 1974;Brown et al, 1980). Later-stage disease is characterized by pedunculated, exudative, ulcerating masses that can become as large as 10 cm or greater in diameter (Rust, 1949;Kimeto and Mugera, 1974;Brown et al, 1980;Mello Martins et al, 2005).…”