Rabies is probably the oldest and most well-known (if also misunderstood) of the diseases that can affect almost all warm-blooded mammals.
Dogs are easily vaccinated against rabies. Most counties and cities require that all dogs be vaccinated before they can get their dog licenses, and veterinarians must report all the dogs they vaccinate. Thus it has one of the highest compliance rates of all the routine dog vaccinations available.
Rabies is transmitted by body fluids — urine, saliva, or blood. Ironically, if your dog tangles with a rabid animal, you may be more at risk than your dog, since your dog is the one with regular rabies shots, whereas these are rarely administered to humans.
For rabies to infect you, it must come in contact with the skin or be ingested. Dogs and cats can ingest it by getting the saliva or blood of a rabid animal in their mouths where it will be absorbed through the mucous membranes. Humans are particularly at risk because we have so many minute cuts in our skin that if we touch our dog or cat after they have met a rabid animal, we can become infected.
Keep in mind that bites are the most common way for humans to contract rabies from dogs, although other routes are possible. Some other methods, such as urine spray from flying bats, have been documented as a means of transmitting rabies — but you are unlikely to encounter dogs flying overhead.
Rabies cannot be detected by a blood test because it invades the neural system. The only detection at this time is by examining the brain after death for signs of the infection. The incubation time is 3–6 months, which is why the standard quarantine for animals in some countries is 6 months.
Call the local health inspector, animal control officer, or police if your dog or cat has tangled with another animal that you suspect might be rabid. Dogs and cats who have been vaccinated against rabies should wear a tag at all times when not in the house to prevent being destroyed to check for rabies. Most veterinarians will recommend another booster as soon as possible if the dog has been bit or is suspected to have been bit.
The sooner the better to help protect against the virus before it has time to spread.