Illinois officials announced recently that an 8-year-old dog of mixed Irish Setter and Golden Retriever breeds was diagnosed as having been ill with West Nile virus (WNV). Because of the severity of the illness, the dog was euthanized. While testing confirms that the dog was infected with West Nile virus, this report does not significantly change what experts believe to be true about dogs and their susceptibility to WNV.

This dog is reported to have suffered from a pre-existing medical condition that led to the severe weakening of its immune system. Because the dog's immune system was unable to fight the virus, exposure through a mosquito bite that would have been inconsequential to a healthy dog, resulted in WNV-caused illness in this dog. While the loss is tragic for the family members of this pet, it does not change what experts believe to be true concerning companion animals and their risk of contracting WNV, which is that it is very unlikely for healthy dogs (or cats) to become ill with this virus. Pet owners should do the same things that they should do to protect themselves and family members: eliminate mosquito habitat and avoid mosquito exposure. Private veterinarians may also be consulted for recommendations on safe, effective mosquito repellents that may be used on pets (DEET-containing products are not approved for pets and should not be used).

Veterinarians wishing to test dogs for WNV should contact either the Diagnostic Laboratory at Cornell University in Ithaca, New York, or the National Veterinary Services Laboratory (NVSL) in Ames, Iowa. Questions concerning testing of other pet animals should be directed to the NVSL. Questions concerning the testing of wild animals for WNV (squirrels, deer, etc) should be directed to the Michigan Department of Natural Resources.