We do not recommend doing titers, but if an owner would like to do a titer for Distemper and Parvo we can. The problem with doing titers is that it is only checking titers for two of the 9 things in our DHLPP vaccine. So the animal could have immunity for Parvo and Distemper stilll, but not for Adenovirus or parainfluenza and we would have no way of knowing. Lepto always needs to boostered every year because it is a bacteria not a virus and does not stay in the immune system memory for longer than a year. It will not hurt their immune system to get another vaccine if their titers are still good. For these reasons, we recommend doing a DHLPP vaccine yearly because it covers all of these scenarios.