Possible side effects of parvo shots include pain, swelling, low-grade fever and reduced appetite for one or two days. Some puppies have an inability to acquire the necessary antibodies from the vaccination, notes Vetinfo. Even with a shot, a vaccinated puppy can still contract and die from parvo.
A serious, potential side effect of parvo shots is developing autoimmune hemolytic anemia or AIHA, reports Petfinder. The condition occurs when the vaccine triggers the production of antibodies against red blood cells, leading to weakness, lethargy, lack of appetite, breathing difficulty and various other symptoms. When a dog develops AIHA, the life-threatening condition can necessitate lifelong therapy.
Puppies can experience pain and swelling at the site of the injection, explains Vetinfo. Some dogs become less active on the day of getting the vaccination, but they typically return to normal behavior the following day. Animals with allergies often suffer worse allergies when they are vaccinated during an allergy season. Vetinfo suggests administering puppy shots after allergy season if a dog has allergies to pollen, mold spores and other elements.
Dogs that have been exposed to the parvovirus prior to getting vaccinated sometimes develop parvo, because there is not enough time for the vaccine to work effectively, states Vetinfo. Also, puppies can contract the virus post vaccination if the vaccine is not stored properly prior to being administered.