Pathogenesis of rabies virus infection in dogs.

Most dogs experimentally infected with street rabies virus showed clinical signs of rabies before death, but up to 18% of the dogs died without showing detectable signs of illness. In dogs showing signs, rabies was not invariably fatal. Up to 20% of dogs recovered without any supportive treatment. Some dogs inoculated with American (southern Texas) or Ethiopian canine street virus excreted virus in their saliva up to 14 days before signs appeared. There was no relation between the time of excretion of virus in the saliva and the titer of virus in the salivary glands at death. One dog that recovered from rabies intermittently excreted rabies virus in its saliva for a long time. The carrier state in rabies may play a significant role in the perpetuation and survival of the virus and may become a source for rabies outbreaks whenever a new generation of rabies susceptibles reaches critical density.