DA2PP vaccines are strongly recommended for adult dogs. This vaccinates for distemper, adenovirus type 2, parainfluenza and parvovirus, and the adenovirus type 2 portion of the vaccine cross-protects against adenovirus type 1 and infectious canine hepatitis. Infection with any of these can be deadly.
Vaccinating Your Pet
Unless your dog has had a severe vaccine reaction, which is rare, she should be vaccinated with a DA2PP booster. Most vaccine manufacturers recognize that adult dogs develop a lasting immunity, so your veterinarian will usually only need to vaccinate your dog every three years after the initial vaccine series. The other viruses are relatively rare, but parvovirus is a common, highly communicable virus that your dog can get from another canine. The virus is difficult to kill in the environment, as well. If your dog is infected with parvovirus, expect that she'll need to be hospitalized for an extended period of time. With delayed treatment, her prognosis will be poor. Distemper also presents a poor prognosis for affected dogs. While no vaccine is 100 percent effective, the risks of infection merit vaccinating your dog.