We do titers on Ellie now and will be vaccinating every three years even if the titers are good (that is what her vet is comfortable with). I think 95% of dogs retain immune anywhere from 7 years - a lifetime, so I think they are a waste for the most part but hey, it gets me out of vaccinating.
Ellie had the parvo and distemper done ($85 altogether).
It is just a simple blood test and it is sent to a lab (Colorado State in our case). You will get the results within two weeks.
Ellie had been vaccinated the year before but I think they did too many at once because her parvo came back fine but her distemper was only 1:16, so I really had no choice but to vaccinate against it again.
So yes we use them but they don't give the whole picture and they don't take into account that just because there is a low titer, there are still memory cells and the dog would probably be protected anyway.
They are nice though for those who don't want to vaccinate...
It is certainly fair to vaccinate if there is a low titer though. It is better than vaccinated before even looking...
Does that help?