Systematic Veterinary Virology

SYMPTOMS

• Clinical signs of rabies are not very definitive. Rabid animals of all species exhibit typical signs of CNS disturbance, with minor variations among species. The most reliable signs, regardless of species, are behavioral changes and unexplained paralysis.
• Behavioral changes include anorexia, signs of apprehension or nervousness, irritability, and hyperexcitability. The animal may prefer to be in isolation. Ataxia, altered phonation (sound), and changes in temperament are apparent. Uncharacteristic aggressiveness may develop—a normally docile animal may suddenly become vicious. Commonly, rabid wild animals lose their fear of man, and species that are normally nocturnal may be seen wandering about during the daytime.
• The clinical course is divided into three phases—prodromal, excitative, and paralytic. During the prodromal period, which lasts 1-3 days, animals show only vague CNS signs, which intensify rapidly. The disease progresses rapidly after the onset of paralysis, and death is virtually certain within 10 days after the initial onset of signs. Some animals die rapidly without marked clinical signs.
• Normally rabies is exhibited as
• “Furious rabies” refers to animals in which aggression (the excitative phase) is pronounced and
• “Dumb or paralytic rabies” in which the behavioral changes are minimal or absent, and the disease is manifest principally by paralysis.