Adverse Effects of Rabies Vaccinations in Cats on Prednisone

For an immuno-suppressed feline on prednisone, the rabies vaccination poses more risks than it does for a healthy cat. Shots given to an unhealthy animal can fail to provide immunity and even further weaken the immune system. According to vaccine manufacturer Pfizer, "a protective immune response may not be elicited" in immuno-compromised animals. Since prednisone suppresses an immune response, says Barbara Forney, DVM, of Chester County, Pennsylvania, vaccinating during steroid therapy is not advised. Many adverse side effects can follow vaccination immediately or up to 45 days after the shot, says Jean Dodds, DVM, and can cause minor symptoms, such as swelling at the injection site, and life-threatening conditions such as seizures, and liver and kidney damage.

  1. Swelling at Injection Site

    • Rabies vaccine poses risks for cats on prednisone

      Knowledgeable veterinarians typically inject the rabies vaccine in the right rear leg (as distally as possible) to avoid post-injection swelling. Administering the vaccine between the shoulder blades is no longer considered a safe practice, due to the elevated risk of causing vaccine-related sarcoma, an aggressive cancer, according to Pawprints and Purrs. The American Veterinary Medical Association states that the development of a small, non-painful lump under the skin at the site usually goes away after several weeks; however, you should report it to your veterinarian.

    Seizures

    • If your cat is on prednisone, it's likely dealing with an immune disease or cancer, as veterinarians most commonly prescribe steroids for these conditions. Extra precaution needs to be taken when choosing whether or not to vaccinate, because cats with autoimmune disease are more susceptible to seizures following injection. As a neurogenic protein, the rabies vaccine affects the nervous system. Seizures or seizure-like disorders, such as stumbling, ataxia, dementia and motor-skill impairment, can result from the vaccine, according to Animal Wellness Magazine.

    Liver and Kidney Damage

    • Kidney and liver damage can occur if the rabies vaccine triggers the immune system to attack healthy, functioning cells. The rabies vaccine "can also have an autoimmune-like destruction of tissues, skin, blood, joints, the liver or kidneys," Dr. Dodds says. "Animals already ill with immune-related diseases such as cancer can be even more negatively affected. Often, this is the last thing that causes the animal's demise."