Normal Side Effects of Puppy Shots

Puppies start receiving vaccinations when they are six weeks old. They will receive boosters every three weeks until they are 16 weeks of age. According to VetInfo.com, this is necessary because it is hard to determine at what age the vaccines become effective. The five most common and most important vaccines puppies receive are hepatitis, distemper, parvovirus and rabies. Side effects range from mild irritation at the site of the injection to anaphylactic shock.

  1. Pain

    • The most common side effect is pain at the site of the injection. There might also be slight swelling causing discomfort. The site of injection may also show redness. These effects should last no more than one week, according to PetEducation.com.

    Lethargy

    • Some pups become lethargic for a day or two after vaccination. They may lose their appetite and even develop a slight fever. Allergies may worsen if the vaccines are given during allergy season.

    Anaphylaxis

    • PetEducation.com warns of the life-threatening anaphylactic allergic reaction some puppies have to vaccines. If not treated promptly, the puppy can go into cardiac and respiratory failure, followed by death. The window of susceptibility is anywhere from a few minutes after vaccination to 24 hours after. Symptoms to watch out for include diarrhea, seizures, vomiting, coma and shock. The vaccines that present more of a risk for anaphylaxis are rabies, leptospirosis and coronavirus.

    Neurologic Disease

    • Distemper vaccinations can cause inflammation of the brain. A puppy's nervous system may be damaged by the measles vaccination. Any modified live vaccine given to pups younger than five weeks may cause them to develop cerebellar disorders. Eye inflammation may develop in puppies in response to vaccines containing canine adenovirus 1.