Laboratory diagnosis of rabies in dogs and other animals is useful to assess the risk of infection and to monitor postexpo-sure prophylaxis in humans bitten by the animals.
The brain of the dead animal is the specimen of choice. The brain is collected carefully from the dead animal. Part of the specimen is collected in 50% glycerol saline (preservative) for isolation of virus. The other part of the brain including the hip-pocampus and cerebellum (abundant in Negri bodies) is col-lected in Zenkers’ fixative for demonstration of Negri bodies.
Impression smears of the brain tissue are stained by Seller’s technique for demonstration of Negri bodies. This is still a useful method in the laboratories lacking facilities for cell cul-ture and antigen detection methods.
Demonstration of viral antigens in the infected brain tissue and in saliva of the animal by DFA is a useful method for diagnosis of rabies in animals. Detection of antigen in the saliva shows whether the animal was excreting the virus in the saliva or not.
Viruses can be isolated from animal brain issue and saliva by culture in cell lines or in animals, as described earlier for diag-nosis of human rabies.