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Vaccine Reactions in Dogs

Vaccine Reactions in Dogs

The benefits of having your dog vaccinated typically far outweigh the risk of reactions to the vaccines. That said, some dogs do react to getting their shots. Here's more from our Riverside County vets on the most common reactions to vaccines in dogs, and what to do if your dog has a reaction.

Why should I get my dog vaccinated?

By making sure your dog is vaccinated early in life, and regularly as an adult, you provide them with the best chance at a long, healthy life. Diseases such as rabies, hepatitis, and parvovirus can be very serious and even fatal, particularly in puppies. Vaccines prevent these diseases from developing in the first place, which is always preferable to treating them once they exist in your pet.

Does my dog need all the available vaccines?

Your vet will evaluate the risk factors for your dog based on breed, age, and lifestyle, and then advise you on which immunizations are appropriate for your dog.

What are the most common reactions to vaccines in dogs?

Adverse reactions to medical procedures are unavoidable, and vaccines are no exception. It can be upsetting for loving pet owners to see their pets react to vaccines, but it's important to remember that most reactions are mild and short-lived. Knowing the signs of a reaction and what to do if your dog has one can make vaccination time less stressful for both you and your dog.


The most common reaction dogs have to get their shots is general lethargy and discomfort, which is often accompanied by a mild fever. Many of us would describe this sensation as 'off'. This reaction indicates that your dog's immune system is functioning properly and responding appropriately to the vaccine. These minor symptoms are normal and should last no more than a day or two. Contact your veterinarian if your dog isn't back to normal within a few days.

Lumps & Bumps

As with feeling 'off', lumps and bumps can be a common reaction to vaccinations in dogs. Following the vaccination, a small, firm bump may develop at the spot where the needle was injected into the skin or muscle, leaving the area somewhat tender. These bumps develop due to your dog's immune system rushing to resolve the localized irritation at the site. 

However, any time the skin is punctured, there is a risk of infection. Keep an eye on the area where the injection was given. Examine for swelling, redness, discharge, and pain. Infected areas, if left untreated, can lead to more serious conditions. Contact your veterinarian if you notice the area becoming increasingly red or exhibiting any of the symptoms listed above.

Sneezing & Cold Like Symptoms

While most vaccines are administered via injection, the Bordetella bronchiseptica and parainfluenza virus vaccines are administered via nasal drops or sprays. These vaccines can cause symptoms similar to a cold, such as coughing, sneezing, and a runny nose. Most dogs recover within a day or two of experiencing these symptoms. If your dog exhibits more severe symptoms or does not recover within a few days, it is time to consult a veterinarian.

Serious Reactions to Vaccinations

Most reactions associated with vaccines are short-lived and mild. Nonetheless, in a few rare cases, more severe reactions can occur and require immediate medical attention. Anaphylaxis is a severe allergic reaction characterized by facial swelling, vomiting, hives, itchiness, diarrhea, and breathing difficulties. Anaphylaxis typically occurs very soon after the dog receives the injection but may 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.

Can I prevent my dog from having a reaction? 

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

However, if your dog has had a previous reaction to a vaccine, you should notify your veterinarian. In the future, your veterinarian may advise you to forego a particular vaccination.

The risk of reactions to vaccinations increases somewhat when multiple vaccinations are given at one time. 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.

To learn more about vaccinations and preventive healthcare for your dog, contact our Riverside County vets today to book an appointment.

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Banning Veterinary Hospital is accepting new patients. Our experienced and compassionate vets care about the health of animals across Riverside County. Contact us today in order to book your first appointment.

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