What the letters mean
- D — canine distemper, a serious viral disease affecting the respiratory, gut and nervous systems.
- H or A2 — adenovirus type 2, which protects against infectious canine hepatitis (adenovirus type 1).
- P — parvovirus, a severe and often fatal gut infection, especially in puppies.
- P — parainfluenza, a respiratory virus that contributes to kennel cough.
You will see it written as DHPP, DAPP, DA2PP or DHPPi. Some products add leptospirosis (DHLPP). They are the same core vaccine with different labels.
The puppy series
Puppies are vaccinated every two to four weeks from around 6 to 8 weeks old until at least 16 weeks, because the antibodies they get from their mother interfere with the vaccine at an unpredictable point. The last dose at or after 16 weeks is the one that matters most.
Boosters
A booster is given within a year of the puppy series (many vets now give it at around 6 months), and after that every three years is the usual interval under current guidelines. Your vet may adjust this for your dog.
Titers
For distemper, adenovirus and parvo, a blood test can show whether protection is still present, and some vets and facilities accept it in place of a booster. See titer tests instead of boosters.
Sources
Rules and guidelines change, and businesses set their own policies. Confirm with your vet and with whoever is asking.