Everything You Should Know About Vaccine Reactions In Dogs

It's important to start vaccinating your dog when they are still a puppy to protect them from common illnesses and diseases. However, some owners are worried about their dogs developing reactions to their vaccines. In this post, our Riverbank vets explain why vaccinations are important for puppies and dogs and what to do if they do develop a reaction to their shots.

Why It's Important For Dogs To Be Vaccinated

Annual vaccinations are very important for dogs because they help protect them from contracting highly contagious, serious diseases that could threaten your pup's long-term health. In most cases, the benefits of having your dog vaccinated far outweigh the risk of your dog developing a reaction to the vaccines. That said, some dogs do have reactions to their shots.

Common Vaccine Reactions In Dogs

It can be upsetting to see your dog have an adverse reaction to their vaccines. But, it's important for caring pet owners to know that most reactions are mild, short-lived, and usually far less dangerous than the illnesses the vaccines help prevent.

 When you understand what the most common vaccine reactions in dogs are, and what to do if your dog does develop a reaction, vaccination time can be less stressful for you and your pooch.


The most common reactions dogs have to their vaccines are lethargy, mild discomfort, and a slight fever. This is often characterized by your dog just not acting like their usual self; perhaps being a bit lazier than usual. These are normal vaccine reactions in dogs, and the symptoms should be mild and only last one or two days. If your dog's reaction continues for more than a couple of days, contact your vet.

Lumps & Bumps

It's common for dogs to develop lumps and bumps on their skin after being given a vaccination. A small, firm bump can arise near the spot where the needle was injected into the skin. This is also a normal reaction, but it's important to monitor it to make sure the bump doesn't keep growing or show signs of infection such as becoming more painful, inflamed, or oozing. The lump should gradually go away over the course of about a week. If the lump shows signs of infection, or it hasn't disappeared after a week, call your veterinarian.

Any time that your dog's skin is punctured there is a chance of infection. Keep an eye on the site where your dog's injection was administered. Watch for signs of infection such as increased redness, swelling, pain, or discharge. Infections can result in more serious conditions if they go untreated. If you notice that the spot where your dog had their injection is becoming inflamed and sore, contact your vet.

Cold Like Symptoms & Sneezing

While most dog and puppy vaccines are administered through an injection, the Bordetella bronchiseptica and parainfluenza virus vaccines are administered by drops or sprays into the dog's nose. Reactions to intranasal vaccines look similar to a cold and can include symptoms such as a runny nose, coughing, and sneezing. Expect your dog to recover from these symptoms within a day or two. If your dog does not recover after a couple of days, or their symptoms become more serious call your vet.

Serious Reactions Dogs Can Have to Vaccines

Vaccine reactions are usually short-lived and mild. But, in a few rare cases more severe reactions can occur and require immediate medical attention. Anaphylaxis is a severe allergic reaction that can be characterized by facial swelling, vomiting, hives, itchiness, diarrhea, and breathing difficulties. Typically, dogs develop anaphylaxis very soon after the vaccination has been administered, however, it can occur up to 48 hours after the vaccine.

If your dog shows symptoms of anaphylaxis after being given their shots, call your vet immediately or bring your pooch to the nearest emergency veterinary clinic.

How To Prevent Vaccine Reactions In Dogs

Vaccines are essential for protecting your dog against a handful of potentially fatal and contagious diseases. The risk of your dog having a serious reaction to a vaccine is very low.

On the other hand, if your dog has had a previous reaction to a vaccine, is having trouble walking after their shots, your puppy is crying/yelping when you pick them up after their vaccinations, or exhibits any of the symptoms above, it is important to call your veterinarian and let them know. Your vet will explain your next steps and might suggest skipping a specific vaccination in the future.

Your dog's risk of vaccine reactions may increase slightly when being given multiple vaccines at once, particularly if they are a smaller dog. Your vet may recommend getting your dog's shots over the course of several days rather than all at once, in order to help reduce your dog's risk of reacting to their vaccines.

Contact our Riverbank vets today to schedule your dog's vaccinations.