Potential Vaccine Reactions

Vaccination is a safe and effective way to protect pets and people from serious disease. Vaccination is the most common veterinary preventative medicine procedure.

There is less than 5% chance of a pet having an adverse reaction to a particular vaccine. This reaction is usually caused by the adjuvant which is in the vaccine to stimulate the immune system. Many vaccines are now adjuvant free. Pets can experience some mild side effects from vaccination. They can start within hours of vaccination; symptoms are usually mild and go away in a day or so. This is the animal’s immune system processing and developing the immunity their body needs to protect them.

Top Five Symptoms

  • Mild fever
  • Decrease in social behavior
  • Decreased appetite or activity
  • Discomfort or soreness at injection site
  • Sneezing or mild respiratory signs from intranasal vaccines

Usually the ADR (Ain’t Doing Right) symptoms resolved uneventfully in a day or so without any long term problems.

Other Common Reactions:

Cats can have a severe, sometimes fatal reaction to vaccinations. This type of reaction happens less than 2% of the time. They have an anaphylactic response (vomiting, diarrhea, salivating and walking off-balance as if they were drunk). This response usually occurs within 15-30 min., but we caution owners to observe their cat for a few hours after vaccination. Sometimes cats will just feel poorly and be lethargic the day following vaccinations. Because of the potential severity of the reaction, our hospital does not change the type of dog and cat vaccines used. This way, we know how our pets will react based upon previous vaccination. However, we do like clients to observe their pets after each vaccination because occasionally the drug companies will improve and therefore change their vaccines.

Dogs can have 3 different types of vaccine reactions:

  1. Anaphylactic response: what we like to call the collapsing puppy syndrome. They can have difficulty breathing. The usually “fall off” the needle. This happens less than 2% of the time and is usually within 10-15 min.
  2. Allergic response: with this reaction, the eyelids, nose, lips and face puff up and the dogs get lumps (hives) all over their body and can become itchy spots or all over. Some pets will vomit or have diarrhea. This reaction can occur within 15-30 min., 1-2 hrs. later or 6-8 hrs later. This reaction usually responds very well to Benadryl.
  3. Delayed cellular response: with this reaction, the dog gets a lump on their body where the vaccine was given. The lump may occur within 1-3 wks of the vaccination, is usually non-painful and may take 1-2 wks to go away.

Rare Reactions:

Part of the surrounding vaccines involves the possibility of vaccine associated tumors and auto-immune disease. Feline Vaccine Associated Sarcomas first came to our attention over 10 years ago. It occurs in less than 4 in 10,000 cats from vaccinations. The researchers do not know whether it is related to the Feline Leukemia or the Rabies vaccine. We take these factors into account when choosing our vaccines where they are administered and by not varying the type of vaccine given. It is our belief that the risk of contracting the diseases against which we vaccinate far outweighs the potential risk associated with the vaccines.
If your pet experiences any of these rare symptoms, you should contact us immediately, as your pet may require additional medical treatment. Call 330-545-2255.

If your pet has had a reaction to vaccines, it will be noted on their medical record. However, you should always alert a veterinary medical team if your pet has had a vaccine reaction before. Sometime we are able to pre-medicate before vaccinates are administered and may have you medicate the pet prior to its visit.

TIP: If your pet is a known vaccine reactor and you have to vaccinate your pet for example to be boarded at a kennel, ALWAYS make your appointment first thing in the morning. The veterinarian may want to keep your pet hospitalized for the day to observe your pet for reactions and treat if needed. If you have a problem, it is better to get the pet vaccinated in the morning so if there is a problem you can get to your regular veterinarian during regular business hours. Otherwise, if you wait until the end of the day you could end up with a trip to the emergency clinic.