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Vaccine Reactions in Dogs: Dog Behavior Change After Vaccination

Vaccine Reactions in Dogs: Dog Behavior Change After Vaccination

Vaccinating your dog brings more advantages than the potential reactions. Although rare, some dogs may have reactions after vaccinations. Discover insights from our Jackson veterinarians about common dog vaccine reactions and how to handle them.

Why Should I Get My Dog Vaccinated?

Ensure your dog receives vaccinations during puppyhood and adulthood to give them the best opportunity for a lengthy and thriving life. Illnesses like rabies, hepatitis, and parvovirus pose significant risks, especially for young dogs, and can lead to high veterinary expenses. Vaccinations are a proactive measure that help prevent these illnesses from arising, which is better than addressing them after they affect your pet.

Generally, the chances of your dog having a strong negative response to a vaccine are minimal and often justified.

Does My Dog Need All The Available Vaccines?

Your veterinarian will review your dog's breed, age, and lifestyle to assess potential risks. They will then recommend the appropriate immunizations for your dog.

What Are The Most Common Reactions To Vaccines In Dogs?

Like any medical procedure, vaccines can sometimes lead to negative effects. This might concern pet owners when they see their beloved pets react to vaccines. However, it's worth remembering that most reactions are mild and brief. Being aware of the signs of a reaction and knowing how to respond if your dog reacts can make getting vaccinated a less worrisome experience for both you and your furry friend.


By far, the most common reaction dogs have to get their shots is a general feeling of lethargy and discomfort, often 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 normal within a couple of days, contact your vet.

Lumps & Bumps

Just like feeling a bit off, it's common for dogs to have lumps and bumps after getting vaccinated. Sometimes, a small firm bump might appear where the shot went in, and the area might feel a little sore. These bumps happen because your dog's immune system is working to fix the irritation at that spot.

Remember, when the skin is poked, there's a chance of infection. Keep an eye on where the shot was given. Check for swelling, redness, gooey stuff, or pain. If you see more redness or any of those signs, talk to your vet. Ignoring it could lead to worse problems.

Sneezing & Cold-Like Symptoms

Unlike typical injections for vaccines, the Bordetella bronchiseptica and parainfluenza virus vaccines are given as drops or sprays into the dog's nose. The reaction to these vaccines might resemble a cold, with symptoms such as coughing, sneezing, and a runny nose. Fortunately, most dogs bounce back within a day or two. If your dog experiences more serious symptoms or doesn't improve after a couple of days, it's best to consult a veterinarian.

Serious Reactions To Vaccinations

While most reactions to vaccines that dogs have will be mild and short-lived, in some rare cases, our canine companions can have more severe reactions that need immediate medical attention.

Anaphylaxis - This severe allergic reaction can involve facial swelling, diarrhea, itchiness, hives, vomiting, and breathing difficulties. This type of severe reaction will usually occur very soon after your pet receives the injection (typically while you are still at the vet's office) but can happen up to 48 hours after the vaccine is given.

Shock - The 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.

Can I Prevent My Dog From Reacting? 

Vaccines keep your dog healthy long-term, and the chance of a serious vaccine reaction is very low.

However, if your dog reacted badly to a vaccine before, tell your vet. They might suggest skipping that shot next time.

When dogs get several shots together, the risk of reactions goes up. This is especially true for small dogs. To lower the risk, your vet might recommend spreading out your dog's shots over a few days instead of all at once

To learn more about vaccinations and preventive healthcare for your dog. Contact our Jackson vets today to book an appointment.

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