Combination Vaccines in dogs

Many canine vaccines are combination or multivalent vaccines. This means a vaccine includes antigens for several diseases all in one injection. At one time, vaccines had as many as seven disease antigens included in one injection. It is now believed that less is better—both because some vaccines simply aren’t necessary for all dogs and because you don’t want to overwhelm a dog’s immune system.

The most common combination vaccines currently are DHPP or DA2PP, both of which are acronyms for distemper, hepatitis, parvovirus, and parainfluenza. Most veterinarians use these minimal multivalent vaccines.

An L added at the end (DHPPL) means the shot also contains leptospirosis vaccine. However, if the dog does require a leptospirosis vaccine, it is now recommended that this be scheduled separately. Rabies vaccine boosters are often staggered as well.

For dogs who have had or are at risk for vaccine reactions, the core vaccines, such as distemper and parvovirus, may be given separately and only boostered as indicated by titers. (Titers measure the immunity present in a dog’s system, but more research is needed to determine exactly what mini- mum titer levels indicate a dog is safe from disease.)