If some form of asbestos cancer has developed in a family member it is not unreasonable to wonder if the same can occur with a pet. Malignant mesothelioma is rare in pets but there is an established history of this disease occurring in animals, particularly dogs. Just as with humans it is most often found in the pleura; less often in the peritoneal cavity. It is an extremely rare occurrence with cats.
The most common symptom is the development of pleural effusion, the onset of fluid accumulation in the respiratory cavity. This condition may cause lethargy and eventually, breathing difficulty that can be observed. In some instances fibrosis affects the pleural or peritoneal membrane, resulting in pressure on the lungs or on the gastrointestinal system and bladder if mesothelioma cancer has developed in the peritoneal cavity. The symptoms at that point will evolve to labored breathing, to vomiting and/or urinary tract problems.
Causes for Mesothelioma in Animals
As with humans the most prevalent cause of mesothelioma in animals appears to be asbestos exposure. Pets can pick up asbestos particles in homes where old asbestos flooring, insulation or textiles exist. They can also pick up asbestos fibers that are brought home on clothing used by a house resident on, for example, a demolition job. The onset of mesothelioma in dogs occurs on the average at eight years of age. A post-mortem examination of dogs that had developed mesothelioma showed evidence of asbestos fibers in the lungs for three of the five dogs examined, or sixty percent. There is also some evidence that exposure to certain chemicals used in pesticides (pentachlorophenol) can cause mesothelioma in animals. It has proven to be a factor in mesothelioma development for laboratory rats.
Some species of dogs appear to be more susceptible to carcinoma than others. Irish Setters, German Shepherds and Bouviers seem to be victims of tumor development more than other breeds. Treatment for the disease is as incompletely developed for animals as for humans. In the case of pets, some veterinarians will assess the degree to which the disease has advanced and either recommend surgery or suggest that radical treatment such as that may be a difficult challenge for the pet and have little ultimate therapeutic value.
- Mesothelioma in Dogs, University of Georgia School of Veterinary Medicine, Kavula et al., http://www.vet.uga.edu/vpp/clerk/kavula/
- Malignant Mesothelioma in Urban Dogs, Veterinary Pathology, Harbison et al, July 1983, http://vet.sagepub.com/content/20/5/531.full.pdf+html
- Toxicology and Carcinogenesis Studies of Pentachlorophenol in Rats, Toxicological Sciences, Chabra et al, June 1999, http://toxsci.oxfordjournals.org/cgi/content/abstract/48/1/14