Canine Transmissible Venereal Tumor
Dr. Deepa Meena 1, Dr. Amit Kumar Meena 2, Dr. Neha Meena 3
1-M.V.Sc. Scholar, Department of Veterinary Surgery and Radiology, P.G.I.V.E.R., Jaipur
2- Ph.D. Scholar, Department of Veterinary Medicine, P.G.I.V.E.R.,
Jaipur
3- Veterinary Officer, Animal Husbandry Department, Rajasthan
Email: deepameena094@gmail.com
INTRODUCTION
Canine transmissible venereal Tumor (CTVT), is a contagious neoplasm also known as canine transmissible venereal sarcoma (CTVS), venereal granuloma, stickers sarcoma and infectious sarcoma is a histiolytic tumour of the both male as well as female dog that mainly affects the external genitalia and occasionally internal genitalia and is transmitted from animal to animal during mating. Venereal transmission is the most common way of infection, but it can be transplanted to other sites and transmitted to the nasal or oral cavities, skin and conjunctive and the rectum by sniffing or licking with genital CTVT. It is located on the base of the penis or prepuce in males, and on the vagina or labia in females. Due to exfoliation on affected region from the sick animal, an atypical neoplastic cell infection occurs on healthy individuals. These may grow slowly over years and become invasive, eventually changing to malignant and metastatic. Coitus being the classic mode of transmission, free-roaming sexually intact mature dogs of either gender is at highest risk to develop CTVT.
ETIOPATHOGENESIS
CTVT is transmitted directly from dog to dog, across major histocompatibility complex (MHC) barriers and through transplantation of viable Tumor cells on damaged mucosal surfaces, during sexual intercourse or other social behaviours such as sniffing and licking. The disease is spread when dogs mate, Spontaneous regression of the tumour can occur, probably due to a response from the immune system. CTVT undergoes a predictable cycle: an initial growth phase of four to six months (P phase), a stable phase, and a regression phase (R phase), although not all CTVTs will regress. The Tumor does not often metastasize, except in puppies and immunocompromised dogs. Metastasis occurs to regional lymph nodes, but can also be seen in the skin, brain, eye, liver, spleen, testicle, rectum and muscle.
SIGNS AND SYMPTOMS
In male dogs, the Tumor affects the penis and foreskin. In female dogs, it affects the vulva. Rarely, the mouth or nose are affected. The Tumor often has a cauliflower-like appearance. Grossly, the Tumor is pink to red, poorly circumscribed, multinodular, raised to pedunculated, soft, friable, ulcerated, and haemorrhagic, with frequent necrosis and superficial bacterial infection. Other Signs of genital CTVT include a discharge from the prepuce and in some cases urinary retention caused by blockage of the urethra. Signs of a nasal CTVT include nasal fistulae, nosebleeds, nasal discharge, facial swelling, and enlargement of the submandibular lymph nodes.
DIAGNOSIS
Diagnosis is based on the environmental history, clinical and cytological findings. Biopsy for histological examination is the most reliable method for diagnosis but cytology is usually diagnostic. Definitive diagnosis can be made by chromosome analysis and transmission studies (Greatti et al., 2004). Cytologically, CTVT cells are round or oval, 14 to 30 μm in diameter, with pale blue cytoplasm that is distinctly vacuolated, with a relatively high nuclear: cytoplasmic ratio. The cells also contain dense chromatin, visible nucleoli and numerous mitotic structures, including anisocytosis and anisokariosys.
Treatment
The methods used to treat TVT are cryosurgery, radiotherapy, surgical resection and antineoplastic chemotherapy that is the protocol of choice in routine clinical treatment. Prognosis is good with chemotherapy. There are chances of reoccurrence after surgical resection.
Chemotherapy
- Vincristine sulphate-
Dose: 0.025 mg/kg wt. IV weekly
- Doxorubicin
Dose: 1mg/kg IV every 3 weeks
Side of Vincristine
- Bone marrow suppression, leukopenia, vomiting, recumbency.
Side effect of Doxorubicin
- Cardio toxic, renal failure, alopecia, gastroenteritis, immediate hypersensivity reaction.
References
Ganguly, B., Das, U. and Das, A.K. 2016. Canine transmissible venereal tumour: a review. Vet. Comp. Oncol. 14, 1–12.
Rouf Rashid Dar, Sheikh Tajamul Islam, Abdul Rouf, John Mohammad Wani, Pooja Dogra, Amir Amin Sheikh, Rohini Gupta, Neeti Lakhani and Mohd Younis Ganaie. 2017. Cytological Diagnosis and Treatment of Transmissible Veneral Tumor in Dog- A Case Study. Int.J.Curr.Microbiol.App.Sci. 6(10): 1365-1369.
