We seem to be seeing more canine papillomavirus cases in dogs in the area as of late. It isn’t a high profile disease – the virus doesn’t typically make dogs sick, it usually just causes warts. Whether there is actually an increase in cases or we’re simply looking for them more carefully is unclear, but it may genuinely be on the rise.
Canine papillomavirus can cause a range of skin problems in dogs, typically warty lesions (papillomas) that go away over time without specific treatment. Usually, a small to moderate number of warts are found in the mouths of infected dogs (see picture right). Sometimes, the lesions can be large and extensive, causing problems and requiring surgical removal. Most often (like warts in people), it’s merely a cosmetic issue that goes away eventually, but it may take months. Depending on the size and extent of the lesions, and whether they are growing or causing problems, treatment may be recommended. This can include crushing a wart to try to stimulate the body’s immune response, or topical administration of certain drugs. Complete removal of the lesions surgically should be curative.
Canine papillomavirus is spread by direct contact between an infected dog and a susceptible dog. However, because it tends not to cause severe disease, this virus doesn’t get a lot of attention in the research world. However, a recent study (Lange et al J Clin Microbiol 2011) has provided more insight into the virus. In the study, researchers evaluated different ways to identify the virus. They then tested 95 healthy dogs at the University of Zurich and identified viral DNA on the skin or in the mouth of over 50% of the dogs. Whether these healthy dogs pose a risk to others is currently unclear, but it suggests that the virus could be transmitted not only from dogs with skin lesions, but from a large number of normal, healthy dogs. If that’s the case, control will be a lot harder, since focusing on just the "sick" dogs (the ones with skin lesions) would miss a big pool of potentially infectious animals.
It’s important to note that people cannot be infected with canine papillomavirus, nor can dogs be infected by papillomaviruses from other species.
Image from: www.marvistavet.com