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Common Reactions to Vaccines in Dogs

Some dogs, when they receive their vaccinations and booster shots, have a reaction. However, the benefits of having your dog vaccinated generally far outweigh any risks of reaction. Here is more from our Scottsdale vets on the most commonly seen reactions to vaccines in dogs and what to do if you suspect your dog is having a reaction.

Why should I get my dog vaccinated?

By ensuring that your dog is vaccinated early in their life, and regularly as an adult, your can provide them with the best opportunity for a long and healthy life. Diseases such as hepatitis, parvovirus and rabies can be serious or even fatal to dogs (particularly as puppies.  Vaccines and able to prevent these diseases from ever arising in your pup in the first place, and as such, are always preferable to treating them once they are diagnosed in your pet. 

Does my dog need all the available vaccines?

Your vet will consider any risk factors which may be present in your dog based on their breed, lifestyle and age, and the advise you about what immunizations would be suitable to administer to your pup. 

What are the most common reactions to vaccines in dogs?

Adverse reactions to  vaccinations are always possible, as they are with any medical procedure. For loving dog owners, seeing their pet have a reaction to a vaccination may be upsetting. However, it is important to remember that the vast majority of reactions to vaccinations are both mild and shot-lived. Knowing what the signs of a reaction to vaccination and and what you should do if you detect one in your dog is a surefire way to help make the experience less stressful for both you and your pup. 


By far, the most common reaction dogs have to getting a vaccination is a general feeling of lethargy and discomfort. This is often also accompanied by a mild fever. This is close to what most people would describe as feeling "off" if they were feeling this way themselves. This reaction is your dog's immune system working well and responding appropriately to the vaccine. These mild symptoms are very normal and should only last a day or two. If your dog hasn't returned to normal within a couple days contact your veterinarian.

Lumps & Bumps

Just like feeling "off," bumps and lumps are a common reaction to vaccines in dogs. After their vaccinations, a small and firm bump may develop in the spot where the needle was injected. The area may be left a bit tender. These bumps are a result of your dog's immune system rushing to resolve the irritation at that site.

Any time the skin is punctured, however, there is a chance that infection can occur. Make sure you keep an eye on the site where the injection was given to your pup. If it shows any signs of abnormal swelling, redness pain or discharge it may be infected. If this is left untreated, infected areas can lead to more serious conditions. If you notice the area becoming increasingly red or showing any of the symptoms listed above, contact your vet.

Sneezing & Cold Like Symptoms

While most vaccines are given to your dog by injection, the Bordetella bronchiseptica and parainfluenza virus vaccines are administered by drops or sprays into the dog's nose. reactions to these vaccinations can look a bit like a cold and will include coughing, sneezing and a runny nose. Most dogs are able to recover from these symptoms within a couple days. If your dog shows more sever symptoms or doesn't recover within 2 days, it's time to call your vet. 

Serious Reactions to Vaccinations

The majority of reactions to vaccines are mild and short-lived. However, in a rare few cases, more severe reactions are possible and can require urgent medical attention. Anaphylaxis is a severe allergic reaction which can cause vomiting, hives, swelling of the face diarrhea and difficulty breathing. If your dog experiences anaphylaxis, it will typically occur very soon after receiving the injection. However, it can take up to 48 hours after the vaccine has been administered to appear. If your dog is displaying 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 in the long term. And, your pup's risk of having a serious reaction to a vaccine is very low. 

That being said, if your dog has had a reaction to a vaccine before, make sure you inform your veterinarian. They may advise you to skip a particular vaccine in the future. 

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 Scottsdale Ranch Animal Hospital veterinary team today to book an appointment.

Get in touch today to book your pet's first appointment.

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