How Do Vets Detect Rabies Titer Levels in Cats?

Titers measure antibodies against a particular disease.
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Many owners concerned about over-vaccinating their cats can now test their felines' titer levels to determine whether to vaccinate. However, some experts warn these tests may not be an effective way to measure the level of protection against diseases.


Titer testing, also known as serology and antibody testing, is a simple blood test to determine whether a cat has responded to its vaccination with a specific “core” virus vaccine, including the rabies vaccine. Titers tell veterinarians if a previously vaccinated cat still has protective immunity and how long that immunity will last. Owners who want to avoid revaccinating their cats unnecessarily, or to confirm that a kitten is effectively vaccinated, may have their felines titered.


Rabies is a very dangerous viral disease affecting the brain and spinal cord of all mammals, including cats, dogs and humans. In cats, rabies is most often transmitted through a bite from an infected animal, but it can also be passed on when the saliva of an infected animal enters the cat's body through mucous membranes or an open, fresh wound. Vaccination is the only sure way to keep your cat from contracting rabies and, in many states, it is the law.

The Pros

Mainly, cat owners choose to have felines titered to limit unnecessary revaccinations. Titers measure whether a cat's antibody levels against rabies are high enough for the immune system to attack the virus should the kitty be exposed to it and if so, many owners feel revaccinating is unnecessary -- if not damaging. While vaccines are very effective against the disease, for cats in particular those injections can cause vaccine-related illnesses, such as deadly vaccine associated sarcomas.

The Cons

Not all veterinarians provide titer testing, and even if they do it is expensive. Your vet may have to send a blood sample to a major lab or university to get results. Titer test results for cats are currently not accepted as a replacement of rabies vaccination in the US, and for cats titer testing is only done for panleukopenia and rabies. Many vets recommend a three-year rabies vaccination protocol for cats .

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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