August is National Vaccination Awareness Month, which is aimed at raising awareness around the importance of pet immunization. The benefits of vaccination far outweigh the risks—however, we say that while keeping in mind that side effects are possible. At Anasazi Animal Clinic in Gilbert, we understand that the concern of vaccine reactions in dogs can be stressful and scary, but this will be mitigated if you know what to watch for and how to respond. If you’ve already gotten your dog or puppy vaccinated, you may be wondering if soreness, lethargy, and even a lump at the vaccine site are normal. We’ll answer these questions and more in today’s post.

Common Vaccine Reactions in Dogs

The following side effects are common, but if they persist for more than a day or two, or if your pet is in a severe amount of discomfort, be sure to contact us. Here are the three most common vaccine reactions:

1. Lethargy 

The most common reactions to vaccination are lethargy and soreness, which may or may not be accompanied by a mild fever. This occurs as a result of an immune reaction to the vaccine. This is the whole point of a vaccine, so this response is completely normal and expected. Most dogs are back to their normal selves within a day or two. However, if your dog has more severe or prolonged soreness or lethargy, or just seems “off,” give us a call—we may be able to prescribe medications that will help your pup feel better.

2. A bump or lump

When a vaccine is injected under the skin or into a muscle, you may notice some swelling or a small bump at the injection site. This is because the vaccine irritates your dog’s tissue and it causes a surge of immune cells to the area. How long does a vaccine lump last in dogs? It is completely normal for this reaction to last a day or two. The lump may be tender to the touch but if you notice it getting bigger (after the first few days), oozing, or becoming more painful, let us know right away. If swelling persists, your veterinarian may want to perform tests to assess the possibility of a vaccine granuloma.

3. Sneezing and runny nose

Some vaccines are administered as drops or a spray squirted into your dog’s nostrils. The vaccines that protect your dog from Bordetella bronchiseptica and parainfluenza virus are the most common intranasal vaccines. 

These vaccines are given through the nose because these diseases are all contracted in the respiratory tract. So it’s not too surprising that adverse reactions associated with the respiratory tract are also possible. Dogs may sneeze, cough, or develop stuffy/runny noses for a few days after intranasal vaccines—these symptoms aren’t anything to be alarmed about.

Less Common Vaccine Reactions in Dogs

Very rarely, dogs will have more serious adverse reactions to vaccines. If you think that your dog is having a serious adverse reaction to vaccination, contact us or your closest emergency vet immediately.

1. Anaphylaxis

Anaphylaxis is a potentially life-threatening allergic reaction. This reaction will occur shortly after receiving the vaccine (usually minutes to hours). Symptoms of anaphylaxis include hives, itchiness, facial swelling, vomiting, diarrhea, and/or difficulty breathing. 

2. Infection 

While rare, any injection can cause an infection or abscess as bacteria can enter the body through the skin and into underlying tissues. Symptoms to look out for include discolored skin (often red), discomfort, discharge, and swelling at the injection site.

Preventing Vaccine Reactions in Dogs

It is important to keep in mind that vaccination will not result in a severe adverse reaction for most dogs. However, if your dog has previously had a bad reaction to a vaccine or has underlying health issues, let us know. It may be best to change or even skip certain vaccines. In these cases, we may perform titer tests, which can determine if previously administered vaccines are still providing protection for your dog, or if boostering is needed. Either way, your dog’s comfort and safety is our number one priority. 

Vaccine Spacing 

The risk of mild vaccine reactions in dogs (lethargy, soreness, fever, etc.) can increase when multiple vaccines are given at the same time. More frequent vet visits with fewer vaccines per visit may lower the risk of these mild vaccine reactions if this is something you are concerned about. We can help you decide if the added cost, time, and stress of multiple vet visits is worth the lower risk, but ultimately it is up to you. 

Give us a Call 

In the unlikely event that your pet has an adverse concerning reaction to their vaccinations like a lump or persistent tiredness, Anasazi Animal Clinic in Gilbert is here to offer our expert medical advice and care. Call us right away. And if you don’t already have a local vet you love, come in and see us! We’d be honored to care for your pets and give them the quality treatment and preventative care they deserve. 


Image by Cedric Clooth from Pixabay