The Titer Test: an alternative to vaccines

In my article Do Vaccinations Cause Addison’s Disease, I discussed how a dog with a lowered immune system (such as a dog with Addison’s disease), regular vaccinations might not be the best choice. An alternative to vaccines is a titer test, which measures how much antibody to a certain pathogen is on your dog’s system at the time of the test. However, titer tests are not without their own problems.

Several titer tests are available on the market: your veterinarian may have them. At first, a titer test seems like a good alternative to re-vaccinating: if your dog’s titer shows high antibodies, great! If antibodies are low, then it would seem a good time to vaccinate. However, titer tests don’t work quite that simply, and a low titer could cause you to give an unnecessary booster shot.

Titer tests are available for major diseases like distemper and parvovirus. There’s also a rabies titer test available. After your pet’s blood is drawn, the lab will dilute the blood sample. If the blood is diluted 1,000 times and antibodies are still present, your pet’s ratio would show up as 1:1000 on the test form. The lab will record your pet’s titer as low or high.

For parvovirus, a protective titer should be above 1:80 and for distemper, above 1:96 is considered protective.  Having a value higher than these figured means that your dog does not need a booster shot. Swedish research showed that 7 out of 10 dogs had high enough values that were protected against distemper 3 years after their last shot.

Morre & Glickman (2004) state that in a hypothetical group of 1,000 dogs tested, 86 might have false negative titers. Still, 86 dogs vaccinated unnecessarily might be better than all 1,000 being revaccinated, which is what would happen without the availability of a titer test.

A 2002 report from the American Veterinary Medical Association did state that titer testing is, for the most part, unreliable. However, many others advocate titer tests as a guide to determine whether you should vaccinate your pet. If you are considering a titer blood test in lieu of vaccinating, the ultimate decision is up to you–but in an immune compromised dog with Addison’s disease, a titer test just might be the right choice.

References

Klingborg et. al.  AVMA Council on Biologic and Therapeutic Agents’ report on cat and dog vaccines. PubMed.

McCaw DL et. al, Serum distemper virus and parvovirus antibody titers among dogs brought to a veterinary hospital for revaccination. PubMed.
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Morre Glickman, L. A perspective on vaccine guidelines and titer tests for dogs. PubMed.

Paul MA, Appel M, Barrett R, et al. AAHA 2003 canine vaccine guidelines and recommendations. PubMed.

Twark L, Dodds WJ. Clinical use of serum parvovirus and distemper virus antibody titers…PubMed.