Side Effects of Puppy Shots

Updated February 21, 2017

Just as with human vaccinations, puppy vaccinations come with risks and side effects. The percentage of puppies that experience adverse reactions as a result of being vaccinated is low, and the benefits of puppy shots definitely outweigh the negatives. Still, as a pet owner it is good to know what side effects may occur before having your puppy vaccinated.

Discomfort and Swelling

Pain at the injection site, irritation, swelling and redness are common, although these side effects don't typically last beyond a week. If these symptoms occur at all, they can last from as little as 30 minutes to one week after vaccination. For swelling and discomfort that lasts beyond a week, or if it seems to progressively worsen, the puppy should be taken to the veterinarian.

Sometimes, abscesses can form as a result of the puppy's body reacting to the vaccine occur; they aren't generally the result of infection.


One of the more serious side effects of puppy shots is anaphylaxis. This is a severe allergic reaction to the vaccination, and if signs of anaphylaxis are present, the puppy should be immediately taken to the veterinarian; shock, cardiac failure and death could result without timely treatment.

Anaphylaxis typically becomes apparent minutes to less than 24 hours after vaccination, and occurs in about one out of every 15,000 puppies that are vaccinated. The signs of anaphylaxis include vomiting, diarrhoea, seizures, pale gums, weak pulse, facial swelling, a fast heart rate and cold limbs.

Epinephrine administered within a few minutes after the onset of anaphylaxis can help save a puppy's life; pet owners who give their puppies shots themselves should have epinephrine on hand and know how to use it.

Neurologic or Eye Disease

The most common side effect of vaccinations in puppies is neurological damage and disease, including inflammation of the brain and eye ("blue eye").


Fever, decreased appetite and decreased activity typically occur one to two days after vaccination, and don't usually require treatment.


Puppies who receive intranasal or parainfluenza vaccinations can develop a cough. While this doesn't typically require treatment, it can spread the virus to other animals around them.


Lameness is a rare side effect of puppy vaccinations. Akitas are susceptible to this and may develop immune-related arthritis in their joints. Some large-breed dogs may develop hypertrophic osteodystrophy (bone disease) after receiving distemper vaccinations when they are between 2 and 7 months old.


Puppies who receive modified live vaccines when they are less than 4 to 5 weeks old are more prone to developing infections.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Melinda Gaines has been a freelance writer since 2006, with work appearing online for YellowPages and other websites. Her areas of expertise include business, beauty, fashion and sports. Gaines attended the University of Houston where she earned a Bachelor of Science in sport administration.