How Are Animals Tested for Rabies?

Rabies is a viral disease that can be transmitted from wild animals to pets, livestock and even humans. The rabies virus is present in the saliva of infected animals and is transmitted through direct contact with infected secretions, such as in a bite. Once a person or animal has been infected, the virus spreads to the brain and causes inflammation and almost always death.

  1. Signs and Symptoms

    • The first way to test an animal for rabies is to observe any sign and symptom that could imply their infection. Because the rabies virus acts relatively slowly -- symptoms develop three to six weeks after contraction -- you can observe a progression of the symptoms. First, you may notice a change in the behavior of infected animals. For example, a usually friendly dog may become reclusive, or nocturnal animals like skunks may suddenly become active during the day. Next, the "furious" rabies stage begins, during which infected animals will attack and bite other animals. The final stage is called the "dumb" rabies stage, and causes infected animals to become paralyzed and die.

    Diagnosis

    • According to animalhealthchannel.com, the only way to be 100 percent sure an animal has rabies is to perform a direct fluorescent antibody test (dFA) on the animal's brain. This test is known as the fastest and most reliable test for rabies and has been successfully used for more than 40 years. Unfortunately for the animal, this test can only be performed after the animal has been euthanized. Other tests that do not require euthanasia involve an examination of the animal's serum, spinal fluid and saliva, but they are not entirely accurate.

    How the Test Works

    • Because infected animals have rabies virus antigens, the dFA test is able to analyze brain tissue and see if it reacts to rabies antibodies. The dFA test works by inserting fluorescent rabies antibody molecules into the animal's brain. The molecules bind to the virus antigens and glow when put under a fluorescent microscope. The dFA test is also sensitive enough to detect the presence of rabies antigens in the skin, but only an analysis of brain tissue can confirm the presence of rabies virus with certainty.

    Considerations

    • To stop the propagation of rabies, pets or wild animals suspected of having rabies should be diagnosed as early as possible. If you see a suspicious-looking animal, do not approach it -- contact an animal control agency instead. Should you be bitten or scratched by a wild animal, wash the area immediately with soap and water for 5 consecutive minutes, and call your doctor. Humans can be treated with postexposure prophylaxis, but only if it is administered before the first rabies symptoms appear.

    Prevention

    • A good way to prevent animals from becoming infected with rabies is to provide them with a rabies vaccine. A variety of effective rabies vaccines exist for dogs, cats, ferrets, sheep, cattle and horses. Vaccinating your pet is crucial, since it protects him from any wild animals that might have rabies and come in contact with him. Even indoor dogs and cats should be vaccinated, because there is always a chance that they could escape or that other infected animals come into your home.