Diagnosing Rabies in Dogs
If you suspect your dog has rabies, call your veterinarian immediately. If it is safe to do so, cage, or otherwise subdue your dog, and take it to a veterinarian to be quarantined. If your pet is behaving viciously, or is trying to attack, and you feel you are at risk of being bitten or scratched, you must contact animal control to catch your dog for you.
Your veterinarian will keep your dog quarantined in a locked cage for 10 days. This is the only acceptable method for confirming suspected rabies infection.
Rabies can be confused with other conditions that cause aggressive behavior, so a laboratory blood analysis must be conducted to confirm the presence of the virus. However, blood testing for the virus is not veterinary procedure.
Diagnosis in the U.S. is done using a post-mortem direct fluorescence antibody test performed by a state-approved laboratory for rabies diagnosis. Your veterinarian will collect fluid samples if your dog dies while in quarantine, or if it begins showing progressive signs of rabies; in which case, your veterinarian will opt to put your dog to sleep (or euthanize it).