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Originally Posted by Wylie's Mom  
Yup on the titering. It's most 'accurate' usage is for dogs who arrive into shelter/rescue and they're trying to confirm whether or not previous vax has ever been given to avoid over-vaxing (just using as example). As far as immunity - it can't confirm it, sadly. A dog can have a positive titer and still get the disease; they can have a negative titer yet still be immune. They can have humoral immunity but no cellular immunity and vice versa.
That said, titers can provide some assurance that some form of immunity *might* be present. |
I read on YT that titering is practically worthless several times, but Dr. Jeane Dodds gives a different story. Since I'm taking her advice on immunization scheduling, I'm worried, if she's all wrong with her advice on titering. Here's what Dr. Dodds says on titer testing. From my understanding, every test has false positives and visa versa, but it's considered to be a low enough effect to make the test still valuable.
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Are there downsides to titering?
There is no downside to titering your pet. However, be aware that some veterinarians may be resistant to performing titer tests in lieu of vaccination. These veterinarians are misinformed and incorrectly believe that measuring an animal’s serum antibody titers is not a valid method of determining his immunity to infectious diseases, or that this testing is too costly.
With all due respect to these professionals, this represents a misunderstanding of what has been called the “fallacy of titer testing,” because research has shown that once an animal’s titer stabilizes, it is likely to remain constant for many years. Properly immunized animals have sterilizing immunity (immunity that prevents further infection even when an animal is exposed) that not only prevents clinical disease but also prevents infection, and only the presence of antibody can prevent infection.
As stated by the eminent expert Ronald Schultz, DVM of the University of Wisconsin in discussing the value of vaccine titer testing, “You should avoid vaccinating animals that are already protected, and titer testing can determine if adequate, effective immunity is present. It is often said that the antibody level detected is ‘only a snapshot in time.’ That’s simply not true; it is more a ‘motion picture that plays for years.’”
Furthermore, protection as indicated by a positive titer result is not likely to suddenly drop off unless an animal develops a severe medical condition or has significant immune dysfunction. It’s important to understand that viral vaccines prompt an immune response that lasts much longer than the immune response elicited by contracting the actual virus. Lack of distinction between the two kinds of responses may be why some practitioners think titers can suddenly disappear.
What if the titer test is negative?
Interpreting titers correctly depends upon the disease in question. Some titers must reach a certain level to indicate immunity, but with the clinically important “core” diseases vaccines, the presence of any measurable antibody indicates protection.
A positive titer test result is fairly straightforward, but a negative titer test result can be more difficult to interpret. This is because a negative titer is not the same thing as a zero titer, and it doesn’t necessarily mean that the animal is unprotected. A negative result usually means that the titer has failed to reach a desired threshold antibody level, but a low titer may still mean that the dog is protected upon exposure, as it doesn’t reflect tissue levels of immunity.
What’s the bottom line on titers?
More than a decade of experience with vaccine titer testing and published studies in refereed journals show that 92 – 98% of dogs and cats that have been properly vaccinated develop good measurable antibody titers to the infectious agent measured. In general, serum antibody titers to the “core” vaccines along with any natural exposures last a minimum of 7 – 9 years, and likely are present for life. This corresponds with what we see clinically, as the number of cases and deaths due to these diseases has decreased significantly in the vaccinated population.
The bottom line is that using vaccine titer testing as a means to assess vaccine-induced protection will likely result in your pet avoiding needless and potentially harmful booster vaccinations. And that is a huge benefit for a simple blood test! Dr. Jean Dodds' Pet Health Resource Blog | Avoid unnecessary vaccines with titer tests (Part III) |
So bottom line, if it only gives "some assurance that some form of immunity *might* be present" it sounds pretty worthless.