Vaccine Reactions in Dogs: Side Effects & What You Should Know

Are you wondering what the most common reactions to vaccines are in dogs and what you should do to handle them? Our Westport vets answer questions we often receive from our clients. 


Why should my dogs get their shots?

We recommend responsible dog owners start to bring their puppy in for regularly scheduled vaccinations when their pooch is very young, to give them the best chance at a healthy, long life. Vaccine boosters will also be needed regularly to maintain your dog's protection against diseases. some of the most important vaccinations for puppies to have include hepatitis, parvovirus and rabies. 

While our vets believe that vaccines are essential for all dogs, not all dogs will require all the same vaccines. The shots your dog needs will vary depending on his or her age, lifestyle and where you live. Have your vet assess these factors, as they'll determine your dog's risk of contracting diseases they should be vaccinated against. The veterinarian can also tell you which immunizations your pet will need. 

Vaccine Reactions in Dogs, Westport Vets

Common Mild Reactions to Vaccines in Dogs

Any medical procedure can potentially have an adverse reaction. While reactions to a vaccine are uncommon when they do occur they tend to be very mild and not last very long. 

Knowing the symptoms of a reaction may help you to spot whether your dog might be having one, and might even help to make vaccination time less stressful for you and your dog. 

  • Sneezing & Cold-Like Symptoms - While most vaccines are administered via injection, the Bordetella bronchiseptica virus and parainfluenza vaccines are provided in the form of nasal drops or sprays. Reactions to these vaccines tend to look like basic cold symptoms and might include coughing, runny nose and sneezing. Expect your pooch to recover from these symptoms within a day or two. If the symptoms grow more severe or your pup is taking longer to recover, contact your veterinarian for advice. 
  • Lethargy - Mild discomfort, sluggishness or just not feeling like their normal self, are among the most common reactions dogs have to getting their shots. Sometimes, this is also accompanied by a mild fever caused by your dog's immune system responding to the vaccination. It's perfectly normal for dogs to experience these mild symptoms and they should only last a day or two. If your dog doesn't seem back to normal within 48 hours, contact your veterinarian to let them know. 

Serious Reactions to Vaccinations 

As mentioned above, most reactions dogs have to vaccines will be mild and short-lived, in some rare cases, pets can have more severe reactions that require immediate medical attention.

  • Anaphylaxis - This severe allergic reaction can involve symptoms including facial swelling, diarrhea, itchiness, hives, vomiting and breathing difficulties. This type of severe reaction will usually occur very soon after your dog receives their injection, (typically while you are still at the vet's office), but can happen up to 48 hours after the vaccine is given.
  • Shock - Symptoms of shock following vaccines can include a slow heart rate, decreased blood pressure, and generalized weakness. You may also see a gray tongue and pale mucous membranes.

If your dog displays signs of anaphylaxis or shock, call your vet immediately or contact the emergency veterinary clinic closest to you!

Treatment For Vaccine Reactions in Dogs

Fortunately, adverse reactions resulting from vaccinations can often be reversed with proper treatment, and your dog should recover very quickly.

If your dog's reaction is not life-threatening and confined to the skin, treatment is likely to include cortisone and/or anti-histamines. Symptoms will usually clear up quickly once treatments begin.

Serious reactions such as anaphylaxis and shock require immediate veterinary care! Medications and intravenous fluids will be provided to help your dog recover and restore your pet's vital signs. Epinephrine and/or cortisone may also be used in these cases.

Preventing Reactions to Vaccines

Keeping your dog's shots up to date helps to protect your pet’s long-term health, and it's important to remember that the risk of having a serious reaction to a vaccine is very low for most dogs.

That said, if your dog has experienced an adverse reaction to a vaccine in the past it’s important to inform your vet so this history can be recorded in your pet's medical files. If a previous reaction has occurred your vet may recommend skipping a specific vaccination in the future.

There is a small increase in the risk of reactions to vaccines when multiple shots are given during a single appointment. This can be especially true for smaller dogs. To minimize the risk of an adverse reaction in your pet, your vet may recommend spreading your dog’s vaccinations out over several days rather than doing them all at once.

Should I have my dog revaccinated?

Knowing your dog's risk of having a reaction again if revaccinated is difficult to predict. Some dogs will have no reaction when they have the vaccination a second time, some dogs will experience the same reaction that they had previously, and in rare cases dogs will experience a serious life-threatening reaction to a vaccine that they have previously had.

If your dog has had a reaction to its first round of shots, speak to your veterinarian about the risks and benefits concerning vaccines and your dog's health. Your vet may recommend not vaccinating your pup for particular diseases based upon your pet's previous reaction.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

Is it time to have your dog vaccinated? Contact our Westport veterinary team to book an appointment to get your dog's shots.

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Poster Veterinary Associates has been providing comprehensive veterinary care for your cherished pets in Westport since 1993.

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