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Titers and Canine Vaccination Decisions
A "titer" is a measurement of how much antibody to a certain virus (or other antigen) is circulating in the blood at that moment. Titers are usually expressed in a ratio, which is how many times they could dilute the blood before they couldn't find antibodies anymore. If the lab was able to dilute it two times, and then didn't find any more antibodies, that would be expressed as a titer of 1:2. If they could dilute it a thousand times before they couldn't find any antibodies, that would be a titer of 1:1000.