A distemper shot for dogs is a vaccine that protects against the canine distemper virus, as well as other diseases. The vaccine is commonly abbreviated as DA2PP, and the "D" in the abbreviation stands for distemper. The vaccine is a combination vaccine that protects against four deadly diseases, including distemper, adenovirus type 2 (hepatitis), parvovirus, and parainfluenza. The vaccine is highly recommended for all dogs, and it is especially important for puppies and older dogs that have not been vaccinated. Puppies can receive the distemper vaccine at six weeks old and then every three to four weeks until 16 weeks old. Immunity may last for three years or more, but the veterinarian may recommend a specific vaccine schedule based on how common distemper is in the area. Without completing the full series of distemper vaccinations, the vaccine will not prevent or lessen the severity of infection.