Calicivirus In Dogs

Calicivirus is a form of virus most often linked to rabbits and cats but not an issue thus far in dogs. Discovered some 70 years ago, calicivirus has become a concern for both scientists and veterinarians since the discovery that it could be jumping species. Canine calicivirus is one of a family of these viruses, which also effect sea lions, cats and rabbits. The trouble with canine calicivirus is that not much is known about it, or how it might affect canine health given only two true cases have been discovered.

These viruses are members of the family Caliciviridae. The four genera within the family are Vesivirus, Lagovirus, Norovirus and Sapovirus. The genera are further divided into several species, of which canine calicivirus is part of the Vesivirus genera. Other species in the same genera include, but are not limited to, cetacean, walrus, sea lion, primate, feline and bovine caliciviruses.

In 1985 and 1990, the only two cases of canine calicivirus occurred. In both cases, the virus was discovered alongside other viruses in the system of the dogs. Some strains of canine calicivirus appear related to feline calicivirus while others appear related to San Miguel sea lion strains, which has made it difficult to find and study a dog-related version.

One of the two true cases of calicivirus in dogs, in 1985, documented the presence of calicivirus without being able to isolate it for genetic comparison. In 1990, a dog had parvovirus as the main culprit for diarrhea and vomiting but tests also noted the presence of the calicivirus. Two forms of complications thought to be related to the calicivirus are inflammations of the tongue (glossitis) and intestines (enteritis). Because of the rarity of a "true" infection, and the apparent presence of other viruses with the calicivirus, what the canine strain effects in dog health is still undetermined.

Vaccines do not exist for canine calicivirus. Because of the rarity of infection, and because the virus of one species can affect a dog such as feline calicivirus infections, vaccines have not been a priority. Feline calicivirus does have a vaccine, and even then, vaccinations against other major viruses afflicting dogs seems to keep the calicivirus at bay as well. Determining if a dog does have a calicivirus infection requires lab work to isolate the virus and molecularly study it to know its identity, which can be expensive.