Dog control policies in countries have been successful in slowing down the spread of canine cancer, but the fatal disease is still highly prevalent in most dog populations worldwide. It is especially prevalent in regions with several free-roaming dogs, according to a survey of veterinarians worldwide.

The study, done by University of Cambridge researchers, found that Canine Transmissible Venereal Tumor (CTVT) is present across the world, and countries with the lowest rates of this disease had the strongest dog control policies. These policies included managing street dog numbers, quarantine policies for imported dogs and neutering and spaying practices.

CTVT is a transmissible disease and is the oldest, most prolific and most widespread form of cancer. It causes genital tumors and spreads through sexual intercourse between dogs. It is one of just two transmissible cancers.

This is the first systematic survey done on the disease worldwide. A questionnaire was sent to 645 veterinarians and animal health workers, and the response indicated that dogs in 90 out of 109 countries have CTVT.

In Northern Europe where there are no free-roaming dogs, the only CTVT cases found by researchers was in imported dogs. In New Zealand, where dog quarantine laws are strict, CTVT was not found. However, it was likely to be found in countries with free-roaming dogs.

Andrea Strakova of the University of Cambridge said, “Although CTVT can usually be effectively treated, lack of awareness of the disease and poor access to veterinary care mean it can go untreated and impact the welfare of dogs. Research and monitoring of this disease may lead to improved methods for disease prevention, detection and treatment.”

Elizabeth Murchisonf the University of Cambridge said, “Our study has suggested that free-roaming dogs are a reservoir for CTVT. Our review of the historical literature indicated that CTVT was eradicated in the UK during the twentieth century, probably as an unintentional result of the introduction of dog control policies. Careful management of free-roaming dog populations, as well as inclusion of CTVT in dog import/export quarantine policies, may help to control CTVT spread.”