What is Adverse Reaction to Rabies Vaccine?

Cats need to have a rabies vaccine to protect them, especially if they are outdoors and have the potential of having personal contact with other animals that could be affected with the rabies virus. In the United States, the number of reported rabies cases in cats exceeds the number of cases in dogs. Rabies is a major health concern since it is able to be passed between species and to humans. 

In most states, it is mandatory for your cat to have the rabies vaccine. Some counties allow for a three year vaccine to be given while others require a yearly vaccine. Be sure to research your county’s laws regarding vaccinations for your cat. If you are unsure about what vaccinations are required by law for your cat, contact your veterinarian for assistance.

Generally, if your cat has a reaction to the rabies vaccine it will be minor. There have been cases, though, where the reaction is life threatening. When your veterinarian administers the rabies vaccination to your cat, be sure to watch your cat closely for several hours for any signs of having an adverse or allergic reaction.

Symptoms of Adverse Reaction to Rabies Vaccine in Cats

Your cat may exhibit mild symptoms of an adverse or allergic reaction to the rabies vaccine. Those symptoms will generally lessen over a few days and then disappear. Your cat may also develop serious symptoms from their vaccine that will need definite veterinary intervention and treatment. If you notice any of these symptoms, mild or severe, contact your veterinarian for an immediate appointment. 

Symptoms of a mild reaction or allergy to the rabies vaccine in cats include:

  • Vomiting
  • Swelling at the injection site
  • Pain at or near the injection site
  • Fever (low grade)
  • Diarrhea
  • Appetite loss
  • Lethargy
  • Itching 
  • Sneezing 

Symptoms of a serious reaction to the rabies vaccine in cats include: 

Vaccine Associated Fibrosarcoma

This is the development of a cancerous tumor at the injection site. The tumor can develop from a few weeks to a year after the vaccination has been given.

Organ Damage

The protein that is in the rabies vaccine can potentially damage your cat’s kidneys, liver and/or central nervous system. Organ damage can occur up to 45 days after the vaccination has been given. 

Anaphylactic Shock

Immediate veterinary care is required if your cat experiences anaphylactic shock, death can occur quickly without prompt treatment. Symptoms of anaphylactic shock include facial swelling, difficulty breathing, coma, seizures, 

Vaccine Induced Rabies

This is extremely rare and only can occur with the live-virus vaccine. Cats will show symptoms within 14 days of the vaccine being administered.

Causes of Adverse Reaction to Rabies Vaccine in Cats

An adverse reaction will occur when your cat is exposed to some form of allergen, in this case, something within the rabies vaccine, and its immune system begins attacking itself. Many times when a cat has a rabies vaccine reaction, it is from the live virus vaccine or from the chemical compounds that are added into the vaccine so they are more effective. Another cause of having a reaction to the rabies virus can be when multiple vaccinations are given at the same time.

Diagnosis of Adverse Reaction to Rabies Vaccine in Cats

Your veterinarian will begin their assessment of your cat by asking about your cat’s medical history including any recent vaccinations, diet changes or environmental changes. They will then conduct a physical examination. A urinalysis, fecal exam, complete blood count and biochemistry panel may be completed to rule out other possible causes of the adverse reaction.

Treatment of Adverse Reaction to Rabies Vaccine in Cats

Once your veterinarian has determined the cause of your cat’s reaction, they will discuss treatment options with you. Usually, mild cases will not require treatments unless it is an antihistamine and/or corticosteroid to stop itching or sneezing. Anti-inflammatories may be given to reduce swelling. 

If your cat has developed a more serious adverse reaction or allergy to the rabies vaccine, your veterinarian will need to administer treatments. These treatments will probably be supportive care in the form of intravenous fluid therapy, oxygen therapy and close monitoring of their vital signs. 

If your cat has gone into anaphylactic shock, emergency measures will need to be taken to keep your cat’s airways open so they are able to breathe. Oxygen support will most likely be necessary. Epinephrine will be given as well as antihistamines.

Recovery of Adverse Reaction to Rabies Vaccine in Cats

Your veterinarian can help you protect your cat from developing a serious rabies vaccine allergy, or another reaction once they know that your cat is sensitive to the vaccine. Using only inactive or dead virus vaccines may help your cat not have as severe of a reaction. Also, ask your veterinarian if three year rabies vaccine will suffice or if your county requires a yearly vaccine. 

Have your veterinarian set a vaccination schedule that prevents your cat from getting more than one vaccine at a time. Prior to giving the rabies vaccine, ask your veterinarian about administering an antihistamine to reduce the allergic reaction that your cat experiences.

Adverse Reaction to Rabies Vaccine Questions and Advice from Veterinary Professionals

Serious condition
0 found helpful
Serious condition

My 2 year old make cat just got a benadryl shot followed by rabies shot. His face swelled the last time and he was out of his mind. Now 2 hours later he is vomitting and his face is swelling again...help...

Dr. Callum Turner, DVM
1184 Recommendations
If Mercy is having a severe reaction again to the rabies vaccine, you should return to your Veterinarian especially if the swelling is interfering with her breathing; apart from Benadryl which was given already there is nothing else over the counter I can recommend for you given the circumstances. Regards Dr Callum Turner DVM

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Domestic shorthair
3 Years
Serious condition
0 found helpful
Serious condition

Has Symptoms

leg is paralyzed

My friends cat had a rabies vaccine and now her leg is totally paralyzed! I go to the same vets.
They told her the cats leg needs to be amputated.Is this the only option? And is this common?
I'm afraid to take my cat back for his rabies shot.

Dr. Callum Turner, DVM
1184 Recommendations
Paralysis induced by a modified live rabies vaccines has been documented, cases usually do not resolve; I would recommend discussing the case with your Veterinarian or visiting another Veterinarian for another opinion. Another course of action would be to speak with the manufacturer of the vaccine for more specific information about other cases reported back. As for your own cat, if you live in an area affected by rabies (few countries are rabies free) it would be best to have your cat vaccinated as the benefits outweigh any risks. Regards Dr Callum Turner DVM

I've had many animals have rabies shots and the two cats i have now receive the shot once a year never any reactions. I feel like that was a fluke reaction. I'd never miss a vaccine especially this one a mouse could wander into your house and give your pets rabies or they could be bitten by a carrier animal at the vets office you just never know. I'd just find a different vet maybe.

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Maine Coon
3 Years
Has Symptoms
Domestic Longhair
Has Symptoms
Yelp When Lifted
Lethargy, At Times Breathes Heavy
No Appetite
My boy was fine....until he had his vaccine. The get gas kept him for observation talking about it could be anything. Aware thatbhes a strictly indoors baby, why give him This? Now it's stressed depressed waiting at home alone crying without my baby game, which is so far costing me close to a thousand dollars