Vaccines have been an essential part of our pet’s preventative health care program for many years. The purpose of a vaccine is to stimulate the pet’s immune system, which is inherently an inflammatory process. It is therefore typical for some joint or muscle soreness to occur, lethargy to be observed, or a mild fever to be present for a day or two following vaccine administration. These reactions are not serious and generally go unnoticed. In general, no special precautions need to be taken- the animal can eat, drink, and exercise normally.
Some pets can have a more severe allergic reaction to vaccines. An allergic reaction is a highly individual inflammatory response against specific proteins entering the body. These proteins can be pollens, dusts, foods, medications, or even vaccines. An allergic reaction to a vaccine might include hives, facial swelling, or nausea. More serious reactions, including shock or sudden death, can occur. The time frame for reactions after vaccines can be immediate (Type 1 reaction) or anytime within the next 48 hours (Type 4 or Delayed Hypersensitivity reaction).
What to do during the reaction
If your pet is having a reaction more severe than general malaise or soreness, call a veterinarian immediately. If it is after-hours, it is prudent to consult the local veterinary emergency clinic. Anti-inflammatory injections are needed to stop the inflammatory cascade before it gets dangerously out of control.
What to do in the future for the pet that has a history of vaccine reactions
- Separating vaccines can help determine which vaccine caused the reaction. Keep in mind vaccines given within 2 weeks of each other can interfere with each other. Therefore, you do not want to separate vaccines by less than a two week period.
- Do not have your pet vaccinated at a vaccine clinic since he/she will need an examination and monitoring on the day of vaccination.
- A pet with a vaccine reaction history should require some special attention in the form of observation in the hospital and pretreatment with an anti-inflammatory medication. You have the option of leaving your pet in the hospital for observation during that day or undergoing the following protocol: A pre-treatment injection is given and you will wait with your pet for 20 minutes. The vaccine is then administered. You will be asked to wait in the waiting room for 20-30 minutes before leaving the hospital. Please allow for an hour of your time if choosing this protocol.
- Keep in mind that although your pet has received a pre-treatment injection, it will still be vital to monitor your pet at home for signs of a vaccine reaction.
Vaccination reactions severe enough to produce shock are extremely rare and are a function of an individual pet’s immune response. For these animals, your veterinarian may advise against any future vaccinations and may opt to monitor a vaccine titer instead. There are also specific medical conditions that may preclude your animal from receiving vaccines. Please discuss any concerns with your veterinarian and remember that vaccine protocols often need to be modified for individual pets.