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Healthy Pet Care Tips

Common Reactions to Vaccines in Dogs

Vaccinations protect your dog against a number of serious illnesses, but owners are often concerned about the risk of adverse reactions to vaccines.  Today our vets explain the most common reactions dogs have to vaccinations, and what to do if your dog has a reaction to getting their shots.

Why are vaccines recommended for dogs?

Proper vaccinations are extremely important in preventing your pet from contracting serious contagious diseases that can threaten your dog's longterm health. Typically the benefits of having your dog vaccinated far outweigh the risk of your dog having a reaction to the vaccines. That said, some dogs do react to getting their shots.

Common Reactions to Vaccines in Dogs

Seeing your pet have an adverse reaction to vaccines can be upsetting. Nonetheless, it's important for loving pet owners to keep in mind that most reactions are mild, short-lived and typically far less dangerous than the illnesses the vaccines protect against.

Vaccination time can be made less stressful for you and your pet by understanding what the most common reactions to vaccines are in dogs, and what you should do if your dog has a reaction to getting their shots.


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

Lumps & Bumps

Lumps and bumps are a common reaction to vaccinations in dogs. After the vaccinations a small, firm bump may develop at the spot where the needle was injected into the skin. This is a normal reaction however it's important to watch to ensure that the bump doesn't continue to grow or show signs of infection such as becoming inflamed, oozing or become more painful. The lump should gradually disappear over the course of about a week. If the lump shows signs of becoming infected, or hasn't disappeared after about a week, contact your veterinarian.

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

Sneezing & Cold Like Symptoms

Most of the vaccines recommended for dogs are given by injection however, the Bordetella bronchiseptica and parainfluenza virus vaccines are administered by drops or sprays into the dog's nose. Reactions to intranasal vaccines look much like a cold, and include symptoms such as a runny nose, coughing, and sneezing. Expect your dog recover from these symptoms within a day or two. If your dog does not recover within a couple days, or has more severe symptoms, call your veterinarian.

Serious Reactions to Vaccinations

Reactions associated with vaccines are usually short lived and mild.  That said in a few rare cases more severe reactions requiring immediate medical attention can occur. Characterized by facial swelling, vomiting, hives, itchiness, diarrhea, and breathing difficulties, anaphylaxis is a severe allergic reaction. Typically, anaphylaxis will occur in dogs very soon after the vaccination has been administered, but it's important to note that can occur up to 48 hours after the vaccine.

If your dog shows symptoms of anaphylaxis following their shots, call your vet immediately or contact your emergency veterinary clinic.

Preventing Reactions to Vaccines

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

Be sure to let your vet know if your dog has a reaction to vaccines. Your vet may recommend that you to skip a particular vaccination in future.

The risk of reactions to vaccinations may be increased when multiple vaccines are given together, particularly in smaller dogs. Your vet may suggest 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.

To find out more about vaccines and other preventive healthcare for your dog, contact one of our PetVet Hospitals to book an appointment today.

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