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Vaccine Reactions in Dogs

Vaccinations protect your dog from a variety of serious illnesses, but owners are often concerned about the possibility of vaccine-related side effects. Today, our Fairfield, NJ veterinarians discuss the most common vaccination side effects in dogs, as well as what to do if your dog has an adverse reaction to their shots.

Why Are Vaccines Recommended for Dogs?

Annual vaccinations are critical in keeping your dog safe from serious contagious diseases that can endanger his or her health. In most cases, the benefits of vaccinating your dog outweigh the risk of a vaccine reaction. Some dogs, however, react to receiving their shots.

Common Reactions to Vaccines in Dogs

It's upsetting to see your pet react negatively to vaccines. Nonetheless, loving pet owners should keep in mind that the majority of reactions are mild, short-lived, and usually far less dangerous than the illnesses against which vaccines protect.

Understanding the most common vaccine reactions in dogs, as well as what to do if your dog reacts to their shots, can make vaccination time less stressful for you and your pet.


Being lethargic after shots is one of the most common reactions to vaccines in dogs. This is often characterized by your dog just not acting like its usual self; perhaps being a little more lazy than normal. This is a normal reaction to vaccinations in dogs, and the symptoms should be mild and only last a day or two. If your dog's reaction continues for more than a couple of days, contact your vet.

Lumps & Bumps

Vaccination-induced lumps and bumps are fairly common in dogs. Following the vaccinations, a small, firm bump may form where the needle was injected into the skin. This is a normal reaction, but keep an eye on the bump to ensure it doesn't continue to grow or show signs of infection, such as swelling, oozing, or increased pain. The lump should gradually disappear over a week. If the lump appears to be infected or hasn't gone away after a week, consult your veterinarian.

Infection is possible whenever skin is punctured. Keep an eye on the area where your dog got his injection. Infection is indicated by increased redness, swelling, pain, or discharge. Infections can progress to more serious conditions if left untreated. If the area where your dog received the injection becomes inflamed and sore, contact your veterinarian.

Be careful, your puppy may be yelping or crying when you try to pick him up after vaccination. Your dog may also have trouble walking after a vaccination, but it shouldn't be anything to worry about.

Sneezing & Cold Like Symptoms

Unlike the majority of dog vaccines, the Bordetella bronchiseptica and parainfluenza virus vaccines are administered via drops or sprays into the dog's nose. Intranasal vaccine reactions are similar to cold symptoms, including a runny nose, coughing, and sneezing. Your dog should be free of these symptoms within a day or two. If your dog does not recover within a few days or has more severe symptoms, contact your veterinarian.

Serious Reactions to Vaccinations

Vaccine reactions are typically mild and brief. More severe reactions, on the other hand, may occur in a few rare cases, necessitating immediate medical attention. Anaphylaxis is a severe allergic reaction that causes facial swelling, vomiting, hives, itchiness, diarrhea, and difficulty breathing. Anaphylaxis in dogs usually occurs shortly after vaccination, but it should be noted that it can occur up to 48 hours later.

If your dog shows symptoms of anaphylaxis following their shots, call your vet or emergency vet immediately.

Preventing Reactions to Vaccines

Vaccines are essential in protecting your dog against several potentially fatal and contagious diseases. The risk of your dog having a serious reaction to a vaccine is very low. 

Be sure to let your vet know if your dog reacts to vaccines. Your vet may recommend that you skip a particular vaccination in the future.

When multiple vaccines are administered at the same time, the risk of adverse reactions increases, particularly in smaller dogs. To help reduce your dog's risk of vaccine reactions, your vet may recommend spreading out your dog's vaccinations over several days rather than all at once.

Contact our Fairfield, NJ vets at All Creatures Great and Small Animal Hospital today to find out more about vaccines and other preventive healthcare. 

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All Creatures Great and Small Animal Hospital is now seeing new patients! Our Fairfield, NJ vets are trained to provide care for a wide range of companion animals including cats, dogs, birds, reptiles, rodents, and more. Contact our veterinary clinic today to schedule your pet's first appointment.

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