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Vaccine Reactions in Dogs: Everything You Should Know

Vaccine Reactions in Dogs: Everything You Should Know

Though vaccinating your dog does carry a risk of reactions, the benefit of lifelong protection against serious diseases and illnesses far outweighs this risk. In this post, our Queens vets discuss dog vaccinations, in addition to potential side effects associated with vaccine reactions.

The Importance of Canine Vaccines

Most dog owners take their pooches to the vet for vaccinations and their yearly wellness exams. While some dogs never have problems or reactions to the vaccinations, others receive the injection and may experience one or several side effects, which will be discussed below. Most side effects are mild and usually subside within 24 hours.

The typical dog vaccines include distemper, hepatitis, parvovirus, rabies, and parainfluenza. 

Vaccine reactions can be stressful for both you and your dog, but they will be less so if you understand which symptoms to look for and how to react.

When & How Vaccines Are Administered

Veterinarians typically inject vaccines into a dog's body using a needle. For certain vaccinations and circumstances, a nasal spray may be used. For example, a dog younger than eight weeks old may receive the Bordetella vaccine as a spray.

Potential Vaccine Reactions

Mild vaccine responses or reactions in dogs are to be expected. While you may find it stressful to watch your dog have any kind of reaction to a vaccine, remember that these reactions are generally very mild and quite short-lived.

Knowing how to recognize vaccine reactions and their symptoms, and which actions to take if your dog displays serious signs of a reaction, can help you prevent your pup from experiencing vaccine-related stress.


A feeling of malaise, discomfort, or lethargy is the most common reaction that dogs tend to experience after vaccinations. This may be accompanied by a very mild fever.

This reaction occurs as a result of your dog's immune system appropriately responding to the vaccine. If your dog is lethargic after his shots, rest assured that these symptoms are normal and should only last one or two days. If your dog isn't back to acting like themselves after a couple of days, contact your vet for advice.

Lumps & Bumps

Lumps and bumps are commonly found around the injection site, especially if a dog receives the injectable form of a vaccine. A small, firm bump may develop, and the area may be stiff and tender. These bumps occur when your dog's immune system rushes to combat irritation at the injection site.

That said, there is a risk of infection occurring any time your dog's skin is punctured. Carefully monitor the site where the injection was given. Check for signs of redness, discharge, swelling, and pain on a daily basis. Left untreated, infected areas may lead to more serious conditions. Contact your vet if you notice the area becoming increasingly red or showing any of the symptoms listed above.

Trouble Walking

You may notice the injection site is swollen after your dog receives their shots. Your pooch may also experience pain in the area, which can lead to limping and paralysis. Posterior (rear end) paralysis – a condition most common in dogs that have had a Rabies shot – means that a reaction causes a dog's back or hind legs to stop working.

As unnerving as this sounds, this paralysis is not permanent and will probably improve by the tenth day after symptoms first appear. If your dog is having trouble walking after getting his shots, watch for limping symptoms or minor paralysis closely and consult your vet for advice.

Crying or Yelping

You might understandably be concerned if your puppy is yelping when you pick him or her up after the vaccination. Your first instinct may be to ask your vet, "Why is my puppy crying when I pick him up after his shots?"

However, this is also a natural reaction and not something to worry too much about. Yelping will typically stop in a few hours, or a day or two at the most. If your puppy is still yelping beyond the two-day mark, contact your vet.

Sneezing & Nasal Congestion

This reaction can be quite common if your dog receives the Bordetella vaccine as a nasal spray. This reaction encompasses several symptoms that appear much like a cold, including coughing, sneezing, and a runny nose. Most dogs recover from these symptoms within a day or two. If your dog is showing more severe symptoms or does not recover within a couple of days, it's time to call the vet.

Severe Reactions to Vaccinations

On rare occasions, your pet may experience a severe reaction and it is important to know what these reactions look like.

The most common of these exceedingly rare reactions is anaphylaxis. This is a severe allergic reaction that can be characterized by swelling in the face, hives, vomiting, issues breathing, diarrhea, and itchiness. This reaction typically occurs within a few minutes or hours of your dog receiving a vaccine, but may take up to 48 hours to appear.

If your dog is showing any of the symptoms of anaphylaxis after receiving vaccinations, contact your emergency veterinarian as soon as possible.

Preventing a Dog's Reaction to Vaccines

If your dog has previously experienced reactions or side effects from vaccinations, always inform your vet ahead of time. They may advise you to skip a certain vaccine in the future to mitigate risks.

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 splitting vaccines up to limit the risk of a 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 your dog due for their vaccinations or booster shots? Contact our veterinary team in Queens to schedule an appointment for your canine friend.

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