Rabies in a vaccinated wolf-dog hybrid.

In March 1993, an 11-month-old neutered male wolf-dog hybrid with a 5-day history of progressive neurologic signs was determined to have rabies. The animal was currently vaccinated for rabies with a USDA-approved canine rabies vaccine. One month prior to becoming ill, the animal was observed carrying a dead skunk in its enclosure in a rabies-endemic foothills region of northern California. The diagnosis was made by direct fluorescent antibody testing and confirmed by use of polymerase chain reaction methods when attempts to isolate rabies virus failed. Seven people required rabies postexposure prophylactic treatment. No rabies vaccine is currently licensed for use in wild animals or in wild-domestic animal hybrids in the United States. A documented case of rabies in a wolf-dog hybrid vaccinated with a USDA-approved canine rabies vaccine underscores the public safety issues faced by veterinarians caring for wild-domestic animal hybrids.