Common Reactions to Vaccines  

Instructions for Foster Caregivers

After receiving a vaccination, your foster dog or cat may experience mild side effects that can include one or more of the following:

• Discomfort at the vaccination site

• Swelling at the vaccination site

• Mild fever

• Decreased appetite

• Decreased activity level

For pets who received an intranasal vaccination (a mist given through the nose instead of as an injection), they may have a:

• Sneeze

• Cough

• Runny nose

• Other respiratory symptoms

These are all normal reactions that are no cause for concern, but if any of these symptoms last more than a day or two or seem severe, contact our foster team.

Some vaccines, especially rabies, can cause a small, firm swelling to develop under the skin at the injection site. This swelling should subside within a couple of weeks. Contact our foster team if the site remains swollen beyond three weeks, is painful, or increases in size.

Serious Side Effects of Pet Vaccines

Side effects of pet vaccines that require immediate attention include:

• Facial swelling

• Non-stop vomiting

• Persistent diarrhea

• Hives (skin is bumpy and itchy)

• Itchiness

• Weakness or collapse

• Severe coughing or difficulty breathing

While serious vaccine reactions are rare, they can happen in any pet at any time. 

If your pet, or foster, has had a vaccine reaction in the past, please let us know prior to their appointment.