Important Titer Testing for Puppies and Dogs.

Titer Testing

Dogs and Puppies Vaccines

Protect! 

What is an “antibody titer”?

The titer test is a number that represents how many times a sample can be diluted and still shows the functional effect tested for. We are looking at the ability of a dog or puppy serum sample to interact with specific viruses.  In your vet’s office, tests for Titers are functional since the sample is tested for the capability to neutralize or inhibit living viruses.  This test is also quantitative because we are looking for the endpoint – the last dilution before the antibody can no longer impede the virus. After all, it has become too dilute.  In-clinic antibody tests that give quick “yes/no” results are convenient when time is short.  However, these tests are not a “titer” since there is no endpoint determination of antibody functionality.  Often, these tests are appropriate for screening and correlate pretty closely with functional, quantitative (TITER) tests.

Is titer testing appropriate for all vaccine agents?

This test is for antibodies against canine distemper, adenovirus (which causes infectious hepatitis), and parvovirus. All of these viruses, known titer thresholds for protection from infection, have been determined by the laboratory or other scientists in this field.  All these agents are grouped as “Core Vaccines” by veterinary vaccine guidelines worldwide and are strongly recommended for all puppies. Other vaccine agents are not good candidates for titer testing because immune thresholds are not known, or the vaccine cannot completely prevent infection.

What is unique about “Core Vaccines”?

The core vaccines for dogs include distemper, parvovirus, and adenovirus (which causes hepatitis).  The diseases these viruses cause are severe and often deadly.  All these vaccines can induce long-lasting sterile immunity, an antibody level that can neutralize these viruses so that infection does not occur ultimately.  Disease-causing viruses cannot enter the animal’s cells and, therefore, cannot replicate.  The virus is rendered “sterile” by neutralizing antibodies. Reaching this level of immunity is the highest goal of vaccination and is the greatest gift and ultimate benefit these modified live vaccines offer.  The Core Vaccines have saved countless dogs and puppies from disease and death due to these viruses.  All puppies should receive these vaccines.

What is the benefit of titer testing? Why not simply revaccinate?

Vaccinal titer testing is a scientifically proven method of determining immunity and protection against the core vaccine agents.  Even a so-called “fully vaccinated” dog may not be actually “immune.”  Titer testing helps to identify animals that would benefit from vaccination.  On the other hand, already immune pets will not see any benefit to receiving another dose of the vaccine virus in question due to sterile immunity.  While the risk of vaccine-associated adverse reactions is small, even a tiny risk is not worth taking when there is no benefit to offset it.

How often should titers be checked?

When quantitative tests are used, a three-year interval is appropriate for most adult dogs. The manufacturers of in-clinic (“yes/no”) screening tests recommend they be used annually. A titer test within the first six months of life and again at one year is appropriate for puppies.

Tell me more about testing puppies for antibodies: What about maternal antibody interference?

Testing puppies to ensure they have become immune after their initial vaccination(s) is highly recommended. The most significant risk factor for failure of the vaccine to immunize is when an antibody neutralizes the vaccine that the puppy received passively from the mother at birth.  While this maternal antibody is above a certain level, it will neutralize the infectious virus in modified live vaccines, just as antibody does when actively produced by an immune animal.  However, the puppy is not actively making maternal antibodies.  It is metabolized and disappears with time, leaving the puppy susceptible to infection.  Puppy vaccines are given multiple times to be sure to catch the right moment when the vaccine virus can infect the puppy to do the job of immunizing her.  If that moment is missed, the puppy goes through months of disease susceptibility until vaccination at one year induces immunity. It is much preferable to discover a lack of immunity as soon as possible through titer testing rather than to find this out the hard way.

Ask your veterinarian for this critical test before their next vaccine!