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Common Reactions to Vaccines in Dogs

Common Reactions to Vaccines in Dogs

We highly recommend vaccinating your dog, the benefits your dog gets from their vaccinations greatly outweigh the risks. In this post, our Danbury vets talk about the importance of vaccinating your dog and share some of the more common reactions dogs can get from their vaccines.

Why It's Important To Vaccinate Your Dog

By getting your dog vaccinated early in life, and keeping their shots up to date as an adult, you give your pup their best chance at a long, healthy life. Diseases such as rabies, hepatitis, and parvovirus can be very serious and have the potential to be fatal, particularly in puppies. Vaccines help prevent the development of these diseases, which is always preferable to treating them once they are present in your pet.

How To Know Which Vaccines Your Dog Needs

Your vet will assess your dog's level of risk, taking their breed, age, and lifestyle into consideration. Then they will recommend the immunizations that are most appropriate for your pup.

The Most Common Vaccine Reactions In Dogs

With any medical procedure, there is a chance for adverse reaction, and this includes vaccines. It can be distressing for loving dog owners to see their pets have a reaction to vaccines, but it's important to keep in mind that most reactions are mild and short in duration. Knowing what the signs of a reaction are and what you should do if your dog has a reaction, can help make vaccination time less stressful for both you and your pup.


A general feeling of lethargy and discomfort is by far the most common reaction dogs have to their shots, often this is also accompanied by a mild fever. Many of us would describe this feeling as being 'off'. This reaction is your dog's immune system working well and responding to the vaccine appropriately. These mild symptoms are normal and should only last a day or two. If your dog isn't back to their usual self within a couple of days, contact your vet.

Lumps & Bumps

As with feeling 'off', lumps and bumps can be a common vaccine reaction in dogs. Following the vaccination, a small, firm bump might form at the location where the needle was injected into the skin or muscle, making the area somewhat tender. These bumps form as a result of your dog's immune system rushing to resolve the localized irritation at the site.

Although, any time your dog's skin is punctured there is a chance of infection. You need to keep an eye on the injection site. Look for signs of swelling, redness, discharge, and pain. If this goes untreated, the infected areas could cause more serious conditions. If you notice the area becoming increasingly red or exhibiting any of the symptoms detailed above, contact your vet.

Sneezing & Other Cold Symptoms

While most vaccines are given through an injection, the Bordetella bronchiseptica and parainfluenza virus vaccines are given through drops or sprays into the dog's nose. Reactions to these vaccines can look similar to a cold, such as coughing, sneezing, and a runny nose. On average, it takes most dogs one or two days to recover from these symptoms. If your dog is showing more severe symptoms or does not recover within a couple of days, it's time to call the vet.

Serious Vaccine Reactions

Most reactions associated with vaccines are short-lived and mild. Nonetheless, in several rare situations, more severe reactions can arise and need immediate medical attention. Anaphylaxis is a severe allergic reaction that dogs can get to vaccines, it is characterized by facial swelling, vomiting, hives, itchiness, diarrhea, and breathing difficulties. Anaphylaxis typically arises very soon after the dog has been given an injection, but can occur up to 48 hours after the vaccine has been administered. If your dog shows any of the symptoms listed above, call your vet immediately or contact your emergency veterinary clinic.

How To Prevent Your Dog From Developing Side Effects

Vaccines help protect your dog's long-term health, and the risk of your pup having a serious reaction to a vaccine is very low.

That said, if your dog has had a previous reaction to a vaccine, having trouble walking after their shots, your puppy is crying/yelping when you pick them up after their vaccinations, or is exhibiting any of the symptoms above it is important to call your veterinarian and let them know. Your vet may advise you to skip a particular vaccination in the future or recommend the next steps.

There is a slightly increased risk for reactions when dogs are given multiple vaccinations at once. This can be particularly true in smaller dogs. To help reduce the risk of reactions, your vet may suggest getting your dog's shots over the course of several days rather than all at once.

Contact our Danbury vets today to schedule your dog's routine vaccinations or to inform us of any reactions your dog is having to their vaccines.

New Patients Welcome

Are you looking for a veterinarian for your cat or dog in Danbury? Mill Plain Veterinary Clinic is now accepting new patients! Contact us today to schedule an appointment.

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