Titer Testing in Dogs

The American Animal Hospital Association updated its Vaccination Guidelines in September 2017. The guidelines include some important decision flow-charts about titer testing and how to respond to the results in a variety of situations. This is an important topic if you want to avoid over-vaccinating your dog. So, I figured it's a good time to talk about Clover's recent titer test results and about titer testing in general since it may be a new thing for you. This is a LONG post. Grab a snack.

What is Titer Testing (also called antibody testing)

Titer tests are blood tests that your veterinarian can do in the hospital or send to a lab that check for antibodies from previous vaccinations.

Essentially, positive titer test results mean that your dog still has enough antibodies -- from previous vaccinations -- to protect him or her from diseases like distemper or parvovirus. 

More and more dog people use titer testing to AVOID OVER-VACCINATING their dogs ... because if your dog still has protection, then there is NO NEED to revaccinate. 

Titer Testing for Rabies NOT ALLOWED

Unfortunately, NO STATES recognize RABIES TITERS instead of revaccination of dogs, so unless your state allows medical exemptions and a dog qualifies for a medical exemption, then by law, you do have to vaccinate dogs for rabies.

In many states, that's now required every 3 years instead of every year. I sincerely hope that the Rabies Challenge Fund is able to prove that rabies vaccinations could be done every 5 years or even every 7 years so that states might change their requirements.

Don't be thrown by references to "1-year" or "3-year" rabies vaccines. It's the SAME vaccine. Get the one labeled as "3-year," though, so that your state won't require you to vaccinate more often than that. 

Why I Do Titer Testing

When Lilly suffered a deadly adverse vaccine reaction to a routine rabies vaccination in January 2012, people rushed to make me the anti-vaccination "face" in the dog world. 

Let's be clear. I am NOT anti-vaccine. Both of our current puppy-girls were vaccinated as puppies. They received:

• 3 combination vaccines that included distemper, parvovirus, and adenovirus (and lepto as well)
• 2 oral bordatella vaccines (since they were attending puppy kindergarten classes)
• 1 rabies vaccine as puppies and 1 rabies vaccine 1 year later (as required by law)

So, I am NOT against vaccines. I am, however, opposed to OVER-vaccination of pets. Having had a dog die from a vaccine, I'm probably far more sensitive to this issue than others might be.

Titer Testing - Let's Talk Ratios

Titer testing (also called antibody testing) is done by diluting the test sample again and again, using a base factor of 2, until a titer cannot be measured (example ... 2, 4, 8, 16, 32, etc).

I'm writing this because MOST of the discussions you'll find about titer testing will tell you that ANY level of measurable TITERS means revaccination is not necessary. Nonetheless, I think it's important to talk about the numbers and what the lab itself says about them.

Some less expensive titer tests ONLY tell you if a titer is detected at all, not the actual ratio. The tests that I've had done so far do give me the full results, which are represented as a ratio -- 1:2, 1:4, 1:16, etc. Recently, I paid $288.50 to have Clover's distemper and parvo titers tested.

According to the lab paperwork I received, here are the numbers you WANT to see.

I'm paraphrasing, but for parvo, the lab report says:

• Anything over 1:8 fine.
• Anything between 1:16 to 1:32 is better.
• Anything over 1:64 is best.

For distemper, the lab report says:

• Anything over 1:2 is fine.
• Anything between 1:2 to 1:16 is better.
• Anything over 1:32 is best.

Titer Testing - A Case Study

Let's look at Clover's titer test results for Distemper and Parvovirus as a case study. 

At the one-year mark, I had titer tests done on both Clover and Tori to make sure the vaccines they got as puppies had worked. (Sometimes, they don't. Some dogs are considered "non-responders" to the parvo vaccine in particular.) ​

Technically, by the guidelines, a dog would be due again for the combo vaccine every 3 years. So, that's when I had Clover's titers tested again -- 3 years after vaccination (even though it was only 2 years between titer testing). 

Clover’s distemper titers are exactly the same as in 2015 (a year after she finished her puppy shots), which is great. Notice that I inserted the levels the lab paperwork say are protective below the orange line, for comparison.

However, Clover's parvo titers dropped from 1:2048 to 1:256. Remember, it's not raw numbers 2048 to 256. The results are reported as ratios / factors, so it's more like a couple of steps down and still WAY over protective levels. (I could not get Excel to allow me to use ratios in making these charts, so the drop in titer levels looks more dramatic in the chart below than it really is.)

IS THIS NORMAL? I tried and FAILED to get other examples to see what kinds of titer drops other people may have seen, so I cannot tell you if a drop like this is common. 

IS THE TEST DIFFERENT? I checked to see *if* the titer TEST itself has changed between 2015 and 2017. It has NOT. 

WAS THERE A GLITCH? I also wonder if it might be a sample or test glitch. We won't know if that's the case until we test Clover again. For example, if her values GO UP next time, then we'll be more confident saying there was some sort of anomaly with the 2017 test results. 

Either way, my veterinarian wants to recheck Clover's titers in 1 year, rather than wait 3 years. So, we'll see how things look in the fall 2018, and I'll report back. 

Time to Revaccinate?

It really depends on your own “tolerances” and how comfortable you and your veterinarian feel about when to revaccinate:

• Do you feel comfortable saying that ANY TITER means your dog does NOT need to be re-vaccinated? 
• Or if test results dropped below "okay" or "fine" levels, would you revaccinate? 

Titer Testing and Revaccination - What Do the AAHA Vaccination Guidelines Say?

That's an interesting question. I feel like for the first time the topic of titer testing and how to make decisions based on the results got a full / fair look in the updated vaccination guidelines. Here are some links so that you can see for yourself:

IMPORTANT LINK: Antibody Testing Versus Vaccination

See the drop-down content details #1 for normal healthy dogs with known vaccination history since that's the most common scenario for well-kept pet dogs. It says that if the dog tests positive for titers, then there is NO NEED TO REVACCINATE

Also look at the drop-down content details #2. I think the decision charts for dogs with health issues are super important, this includes dogs going through cancer treatments, those with chronic illness, and even those with immune-mediated diseases.

Personally, I would quibble with the recommendation to consider revaccinating dogs with a known history of adverse vaccine reactions that don't pass a titer test because we did everything we could to protect Lilly after she had minor vaccine reactions, and ultimately a vaccine still killed her.

IMPORTANT LINK: Antibody Testing Versus Vaccination FAQ

My favorite part of the FAQ is the following statement: 

"Interestingly, recent practitioner surveys indicate that 'owner request' is the most common reason for performing antibody testing in practice."

In other words, it's consumers DRIVING the rise in use of titer testing in dogs.

Examples of When NOT to Revaccinate

Had Lilly survived her adverse rabies vaccine reaction for long enough to be "due" for revaccination we would NOT have done it. We would have gotten her a medical waiver for rabies, and she NEVER would have been vaccinated for anything ever again. 

If you want to read more about a real-life example where a family will be in a position to make revaccination decisions in the wake of a dog being diagnosed with an immune-mediated disease, I recommend checking out Fidose Of Reality, where Dexter was diagnosed with immune-mediated thrombocytopenia. The post includes a video Q&A. 

As Always ... Talk to Your Veterinarian About All This!

So, I'm sharing our experiences and these titer testing details because I think it's important, and I hope it's helpful to you. However, you need to make decisions for YOUR DOGS in collaboration with YOUR VETERINARIAN. 

The Challenge of Daycare and Boarding Kennels Accepting Titer Tests (or not)

You may run into a problem if you want to use dog daycare or a boarding kennel. I'm in the process now of trying to find a good boarding option for Clover and Tori.

Some kennels I've contacted WILL NOT accept titers as proof of disease protection. Others will. 

I'm planning to visit in person the ones I've found that do accept titer testing for parvo and distemper. 

All of them also require the kennel cough vaccine, but I'm okay with that since I would only need to give it before we had a trip planned and not on a routine basis. 

The other option, of course, is to have a pet sitter come into your home. That's NOT an option for us for a number of reasons, but that may be a good way for you to get around the titer versus vaccination issue. 

Share Your Questions and Input on Titer Testing

I'm happy to hear about your experiences with titer testing for dogs. Pop me a note or post a comment. Thanks!