Although the incidence of this disease has been steadily declining due to strict vaccination, quarantine and border control measures, sporadic cases still occur in endemic areas across Latin America, Asia, India, Middle-East and Africa. Some countries are rabies-free, such as New Zealand, Australia, United Kingdom, Europe. Reservoir hosts, such as bats, foxes, skunks and other wildlife are responsible for sporadic outbreaks in some countries.
Transmission is by viral-laden saliva, usually by biting, with incubation periods of 3 - 6 weeks, although longer incubation periods have been reported. The virus reaches the brain via peripheral nerves, but also infects the salivary glands. Hematogenous spread does not occur.
Clinical signs are variable, but consistent findings are behavior changes and progressive paralysis. The behavioral changes are related to progressive neuropathy, particularly the regions responsible for emotional control. Dogs may become aggressive, antisocial, hyperexcitable, fearful or wander aimlessly. Eventual collapse and respiratory paralysis occur, leading to death.
Diagnosis requires histopathological confirmation of characteristic brain changes using histopathology and immunohistochemistry by a government reference laboratory.
This is a notifiable disease, and strict quarantine protocols are required for monitoring at-risk animals in the immediate vicinity. In most countries, widespread culling is required of animals in the vicinity to minimize spread of the disease.
Vaccines are used worldwide as a preventative measure in dogs and are shown to be effective at preventing disease.