Symptoms of the disease may depend upon the corresponding stage or phase in which the individual may be presented. The three prominant phases include, the Prodormal, the Excitable and the Paralytic phases.
Prodromal phase: The dog's behavior may change during this phase. Aggressive and high-strung dogs may become more affectionate than usual. Ordinarily friendly dogs may become either shy and seek secluded areas or they may be rendered snappy and irritable. The dog's temperature may rise slightly, the pupils may dilate and the nictating membrane might cover the eye. Profuse salivation could also be noticed.
Rabies infected dogs usually show a short excitation phase characterized by restlessness, nervousness, irritability, and viciousness. This is followed by depression and paralysis. After a few days, they are unable to bite anymore owing to muscular paralysis. Seeking a quiet place to hide, they eventually die consequent to the rapid spread of paralysis. Sudden death without recognizable signs of illness is also not uncommon. Dogs that develop the Excitable type of Rabies invariably die of the infection within three to five days after the onset of symptoms.
The strain of the virus, the viral proteins and the host cell expression factors contribute towards the pathology o the disease.