Titer Testing: What It Is and Why You Should Consider It. Does your dog really need to be vaccinated?

There are many benefits to vaccination. Vaccinating animals protects not only the individual pet receiving the vaccine, but the greater community against the spread of infection. But there are downsides to over-vaccinating as well, such as triggering illnesses.

That’s where a titer test—sometimes called serum vaccine antibody titering—comes in.  Titer testing can be used to determine if your pet has been exposed to a natural infection, and it can also be used to see if your pet has responded appropriately to a vaccine, by ramping up the production of antibodies in an effort to prepare a defense mechanism should a natural infection enter the body.  They are most commonly used not to replace initial vaccines but rather to assess where revaccination (a “booster shot”) is needed. A titer test is essentially a blood test measuring the existence and level of antibodies to disease in blood. Antibodies are produced when an antigen (like a virus or bacteria) provokes a response from the immune system. This response can come from natural exposure or from vaccination. The titer levels show how many times blood can be diluted before no antibodies are detected. If the titer levels are high enough, it shows that the dog has sufficient immunity and vaccination is unnecessary. In many cases, vaccinating is much cheaper than titer testing, but titer tests allow you to check if your dog indeed needs to be revaccinated before exposing him to the potential risks vaccines carry.

The most common titer tests for dogs look for antibodies in parvovirus, distemper and rabies, and can help pet parents, vets, groomers, kennel owners, and other people who work with dogs learn about animals with unknown vaccination history, or decide if their dogs need additional vaccinations, as titers can show the actual immune response.

Although all dogs benefit from titer testing, dogs that may get the most out of titer testing are previously vaccinated adult dogs, newly adopted dogs whose vaccination or health history are unknown, and puppies, to ensure they have responded to their initial vaccine series. Dogs with medical issues will also benefit.

How reliable is titer testing?

That depends what information you are trying to get from the titer test.  If you are checking to see if your dog has been exposed to an infection like bacterial Leptospirosis, then a high antibody titer would mean that your pet has either been naturally infected or that it has been previously vaccinated.  In a non-vaccinated pet, the level of antibody titer can be a very valuable diagnostic tool for a specific illness because the presence of antibodies reflect previous exposure, but it doesn’t always give a timeframe as to when that exposure occurred.  But a rising antibody titer over a short period of time reflects the presence of an active infection because that immune system is actively responding to that specific ongoing threat.

With all the benefits of titer testing, there are still drawbacks. One is that it requires a blood draw which can be stressful for some pets.

Another downside is that not every place will accept test results in place of proof of vaccination.  Most states don’t accept titers in lieu of vaccines.

To comply with the law, many pet owners will still vaccinate against certain diseases.

Another drawback to titer testing is that it can be expensive.

If you are interested in learning more about pet related topics, see my previous posts here.  Also, Modern Dog Magazine is a great resource for pet health as it has been a helpful resource for me in my research for this blog post.  

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