Will Falconer, DVM Moderator
Good question, Laurie, and we certainly survived for many years without knowing titer info.
The one most useful time to get a titer is this: a few weeks after either a natural exposure protocol or a vaccination. What you'll gain is the knowledge that your animal either got immunized or didn't.
You are correct: if there's any numbers on the report page, you're done. He's been immunized by your chosen route. If there is a big fat zero, you're not done yet.
And, to just put a slightly finer point to it, the presence of antibodies is the indication that the memory cells got triggered and will "keep record" of this germ for a long, long time. Even after those antibodies fall off.
Make sense? I'm glad you brought it up.