Use of exfoliative cytology for diagnosis of transmissible venereal tumour and controlling the recovery period in the bitch.

Transmissible venereal tumour (TVT) is a rare vaginal tumour that can be treated surgically or cryosurgically as well as by radiotherapy or chemotherapy. Vincristine has been found to be very effective for treating TVT. Since vaginal secretion or discharge may contain neoplastic cells, the cytological identification of TVT cells is possible. The present study was carried out in 12 bitches. Vaginal smears were obtained with cotton swab from the anterior vagina and TVT suspected structures. The smears were stained according to Papanicolaou and assessed by light microscopy. Additionally the general condition of the patients was evaluated by haematological and radiographic examinations. In bitches with TVT vincristine sulphate was administered intravenously at weekly intervals. The total treatment period was three to six weeks until no atypical cells were found in the smear. This was the case after an average of 3.2 +/- 1.3 applications. Tumour masses became smaller and by this non-visible from the rima vulva after 4.2 +/- 0.7 applications. During the treatment, two of the 12 bitches (16.7%) suffered from vomiting and diarrhoea while three (25%) showed neutropenia. Twelve months after completion of treatment, the bitches were examined again and vaginal smears were taken in order to control the recovery process or a possible recurrence of TVT. No atypical cells were found in any vaginal smear. By this exfoliative cytology has proved to be a safe and easy method for TVT diagnosis and for observing the recovery process.