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Common Reactions to Vaccines in Dogs

Common Reactions to Vaccines in Dogs

The advantages of having your dog vaccinated usually outweigh the risks of vaccine reactions. Having said that, some dogs do react when they get their shots. Here's more from our Corpus Christi vets on the most common vaccine reactions in dogs, as well as what to do if your dog has one.

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 consider the risk factors facing your dog based on your dog's breed, age, and lifestyle, then advise you on which immunizations are suitable 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 receiving their shots is a general feeling of lethargy and discomfort, which is frequently 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 are a common side effect of vaccinations in dogs. Following the vaccination, a small, firm bump may form where the needle was injected into the skin or muscle, leaving the area tender. These bumps form as a result of your dog's immune system reacting to 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

The majority of vaccine reactions are brief and mild. However, in a few rare cases, more severe reactions may occur, necessitating immediate medical attention. Anaphylaxis is a severe allergic reaction that causes facial swelling, vomiting, hives, itchiness, diarrhea, and difficulty breathing. Anaphylaxis usually occurs within minutes of the dog receiving the injection, but it can happen up to 48 hours later. If your dog exhibits any of the symptoms listed above, contact your veterinarian or an emergency veterinary clinic right away.

Can I prevent my dog from reacting? 

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

That said, if your dog has had a previous reaction to a vaccine, it is important to inform your veterinarian. Your vet may advise you to skip a particular vaccination in the future.

When multiple vaccinations are administered at the same time, the risk of adverse reactions to vaccinations increases slightly. This is especially true for smaller dogs. To help reduce the risk of allergic reactions, your vet may recommend spreading out your dog's vaccinations over several days rather than all at once.

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

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