Genital and Extragenital Canine Transmissible Venereal Tumor in Dogs in Grenada, West Indies

Abstract

Transmissible venereal tumor (TVT) is a widely reported transplantable tumor in dogs, with no breed or sex predilection and with a low metastatic rate. This retrospective study conducted from 2005 and 2011 sought to evaluate the total number of TVT cases, and to report extragenital TVT lesions in dogs from the small tropical island of Grenada, West Indies. Evaluation of the biopsy and necropsy specimens from dogs with TVT was carried out by cytological and histopathological methods. In the present study, we observed a total of 78 dogs with TVT, comprising 40 male and 38 female dogs. Most cases were from dogs between 3 and 6 years; less frequently from older dogs (over 6 years) or younger dogs (1-2 years of age). In the present study, we report 15 cases (19.2%) of dogs with TVT in extragenital sites. Tumors were noted in the nasal cavity, eye orbit, spleen, liver, skin, ribs, subcutaneous, and submandibular, cervical and inguinal lymph nodes. There was also evidence of metastasis to the ovaries in 2 dogs. The most interesting finding was the presence of extragenital lesions without primary genital involvement in 4 cases (5.1%). Our findings emphasize the need to consider TVT on the list of differential diagnosis for masses in extragenital sites in dogs from geographic regions where TVT is prevalent.

Primary oral and nasal transmissible venereal tumor in a mix-breed dog

“…In the current case, diagnosis of TVT was confirmed by histopathology that was similar to previous reports [3,9,11] . We observed a large number of the round cells with a prominent nucleolus and basophilic cytoplasm on cytology.…”

“…Primary extragenital involvement is almost rare. Compared to our results, Chikweto et al reported 19.2% of dogs with TVT in extragenital sites in the nasal cavity, eye orbit, spleen, liver, skin, ribs, subcutaneous, submandibular, cervical and inguinal lymph nodes [3] . He also found evidence of metastasis to the ovaries in two dogs.…”

“…Vestibule and vagina of the female dogs, and penis of the male dogs have been documented as the most affected sites of TVT [3]. Secondary involvement at other sites of the body has also been reported.…”

“…According to the literature, TVT occurs predominantly in the stray dogs of the regions with tropical and sub-tropical climates [3,11] . In contrary, we reported it in an indoor dog from an arid area.…”

“…This canine tumor transmits coitally with no breed or sex predilection [3,4] . TVT is more commonly observed in the free-roaming, stray, sexually active dogs [5,6].…”