Rabies Vaccine Side Effects in Dogs

Veterinarian giving an injection to a brown and white dog lying on a table.

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A rabies vaccine reaction can cause serious problems, but any vaccine has the potential to cause a reaction. It happens when some dogs' immune systems are overloaded and unable to deal with the vaccine(s) appropriately.

Vaccine reactions come when the body develops an overactive immune response to components of the vaccine such as proteins or adjuvants. Vaccine failure, on the other hand, refers to the vaccination being unable to protect against the challenge—the exposure to the agent it should protect against.

Potential Reactions

Immediate reactions are things that you can see either immediately or within a day of receiving the vaccine.

  • Anaphylaxis
  • Facial swelling
  • Difficulty breathing
  • Hives

There is no first aid for a vaccination reaction. Consider this an emergency and take your dog to the vet immediately, even if it is a mild reaction. That way your vet can both record it on his or her notes to be aware of in future vaccinations and report it to vaccine manufacturer and federal overseeing body. Remind your vet in the future of your dog's reaction, and especially let any veterinarian who is not your regular vet know about the reaction.

Will Your Dog React Again?

Sometimes your veterinarian will recommend pre-medications such as Benadryl or steroids prior to a vaccine. Other times, if the vaccine caused a life-threatening reaction, the vet may recommend against it. Discuss how you should proceed with your veterinarian.

Rabies is the only vaccine that is legally required, and it must be given by a veterinarian. If your dog has had a bad reaction to a rabies vaccine, you can ask your vet to write a letter stating that your dog has the potential for a life-threatening reaction to another dose of vaccine. It’s up to the governing bodies in your area whether they will exempt your dog or not.

Signs of Delayed Reactions

Each vaccination may have specific signs of reactions. There are severe reactions (Type I) that typically occur within hours to days after vaccination and also delayed reactions.

The delayed reactions are not so clear. That’s because they may start within a week but can last much longer. Other times they only show up weeks later. These delayed reactions remain controversial as to whether there is a direct link to the rabies vaccine.

Caryl Wolff is a Los Angeles-based dog trainer and dog behavior consultant certified through IAABC, NADOI, and CPDT and other canine professional organizations. She can be reached through her www.DoggieManners.com site.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.