Attention Veterinarians and techs: be sure to listen to Antibody Titer Tests: A Video Featuring Ron Schultz, PhD It’s RACE approved for CE.
Titer testing, also called serology and antibody testing, is a simple blood test to ensure that a dog or cat has responded to vaccination with a specific “core” virus vaccine, for dogs specifically CDV (distemper), CPV-2 (parvovirus), CAV-2 (adenovirus-2), and RV (rabies). Testing can determine if protective immunity exists in a previously vaccinated animal and establish the duration of immunity (DOI). It is a powerful tool for anyone wanting to avoid unnecessary revaccination or to ensure effective vaccination of a puppy or kitten. Titer test results are currently not accepted in lieu of rabies vaccination in the US although USDA rabies titer standards for dogs may be established soon by the nonprofit Rabies Challenge Fund study. Titer testing is generally not useful for testing for Coronavirus or Lyme disease. Titer testing for cats is only done for panleukopenia and rabies and not for herpes and calici. (Note: Titer is pronounced TIGHT er.)
What the World Small Animal Veterinary Association (WSAVA) says about Titer Testing
“Antibody assays for CDV and CPV-2 are the tests of greatest benefit in monitoring immunity, especially after the puppy vaccination series”. (page 9) For cats, see page 15.
“DOI [duration of immunity] after natural infection/disease is life-long.” page 22
“DOI after vaccination with MLV vaccines is 9 years or longer, based on challenge and serological studies.” page 22
What the AAHA Canine Vaccination Guidelines say about Titer Testing for Dogs (pages 17- 19)
“Despite the confusion and controversy surrounding antibody testing, these serologic tests are useful for monitoring immunity to CDV, CPV-2, CAV-1, and RV…. The tests are also medically useful to ensure that a dog responds to a specific core virus vaccine and/or to determine if immunity is present in a previously vaccinated dog.”
“The serologic test is the only acceptable way to ensure a client-owned dog develops an immune response.”
“… dogs that have been actively immunized by vaccination or naturally by infection that have antibodies to CDV, CPV-2,or CAV-1 do not need to be revaccinated. Some clients are now having titers performed for CDV and CPV-2 in lieu of revaccinating.”
“In a study reported in 1997, dogs vaccinated with a product containing CDV [canine distemper] and then placed in an environment without CDV maintained antibody titers for at least 10 yr.“
“It was shown in many studies that antibody to [CDV, CPV-2, and CAV-2] persisted for many years, even in the absence of the viruses or revaccination.”
Hear Dr. Karen Becker, DVM talk about titer testing
When should you test titers?
Test titers no sooner than 2 weeks after vaccination. Puppies may be tested before vaccination to establish when maternal immunity wanes and following the last vaccination after 14-16 weeks of age to determine if immunity was established.
Do titers need to be repeated yearly, every three years or only one time once a positive titer is established?
W. Jean Dodds, DVM, who tests titers in her Hemopet lab, wrote in her article Treating Adverse Vaccine Reactions : “Some veterinarians have challenged the validity of using vaccine titer testing to assess the immunologic status of animals against the common, clinically important infectious diseases.
With all due respect, 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 that not only prevents clinical disease but also prevents infection, and only the presence of antibody can prevent infection.”
Do you need to revaccinate an animal who once had “strong” titers but no longer does?
According to renowned vaccination expert Dr. Ronald Schultz, titer tests “show that an animal with a positive test has sterilizing immunity and should be protected from infection. If that animal were vaccinated it would not respond with a significant increase in antibody titer, but may develop a hypersensitivity to vaccine components (e.g. fetal bovine serum). Furthermore, the animal doesn’t need to be revaccinated and should not be revaccinated since the vaccine could cause an adverse reaction (hypersensitivity disorder). You should avoid vaccinating animals that are already protected. 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.”
Dr. Schultz et al in Age and Long-term Protective Immunity in Dogs and Cats wrote: “Old dogs and cats rarely die from vaccine-preventable infectious disease, especially when they have been vaccinated and immunized as young adults (i.e. between 16 weeks and 1 year of age).
“… even a single dose of modified live virus (MLV) canine core vaccines [distemper, hepatitis and parvovirus] or MLV feline core vaccines [feline parvovirus, feline calicivirus and feline herpesvirus], when administered at 16 weeks or older, could provide long-term immunity [9 years or more] in a very high percentage of animals, while also increasing herd immunity.
Re testing adult dogs or cats or pets with unknown histories, WSAVA Vaccination Group Chairman Michael Day says, in WHAT WE NEED TO KNOW ABOUT VACCINATION AND TITRE TESTING: “In fact, immunologically an adult dog can be primed, immunized and boosted from a single injection of MLV CORE vaccine as there is no inhibitory MDA. However, such dogs may not actually require vaccination at all – either because they have been previously vaccinated or in some instances have acquired natural immunity from field exposure to virus. Owners may therefore be offered serology rather than automatic vaccination in this circumstance. An adult dog with serum antibody to CDV, CAV and CPV is protected already and does not require revaccination at that time point. Similarly, a ‘lapsed’ or adopted adult cat with serum FPV antibody is protected and does not require that component of vaccine at that time point.”
How do you get your dog’s titers tested?
Many major labs and universities perform titer tests. Your vet likely has a favorite lab and can draw blood and send it for testing for you. Note: some veterinarians resist performing these tests and, as a result, charge more than the going rate at other practices. Although titer testing may cost somewhat more than vaccination in the short run, it is a bargain long term. Titers do not have to be repeated yearly or even every three years. By testing rather than vaccinating, you avoid the risk of adverse reactions from unnecessary vaccines and the accompanying cost of treatment. The more expensive rabies titer need be performed only under special circumstances (such as international travel) or to determine immunity of animals with rabies vaccination exemptions.
Large commercial and university labs perform titer testing. Prices vary.
Jean Dodds, DVM, a highly respected veterinary hematologist as well as a pioneer against over-vaccination, performs titer tests at her Hemopet lab and interprets results. The cost as of 6-12 (subject to change without notice) is $45 for both distemper and parvo (tested together) and rabies for $80. Add to that the cost of a blood draw from your vet and sending by mail. Note: Most vets will send the results to any lab you specify.
Inexpensive and quick in-clinic titer tests are now available from VacciCheck for CDV, CPV-2, and CAV-2 at a growing number of practices. Read A Report by Ronald D. Schultz, PhD, Dipl. ACVIM, Professor and Chair, Department of Pathobiological Sciences School of Veterinary Medicine – University of Wisconsin-Madison. They wrote us June 2012 that they have “a feline VacciCheck which tests for the core feline vaccines-panleukopenia, calici and herpes. We should be applying for USDA approval shortly, meaning that feline VacciCheck is at minimum a year away.”
The other in-house test called TiterCHEK® determines antibody levels to Canine Distemper Virus (CDV) and Canine Parvovirus (CPV) in canine serum or plasma samples. For a comparison, read what WSAVA Vaccination Guidelines Group Chariman Michael J. Day has to say about the two tests. Both provide results in about 20 minutes.
Additional articles of interest:
More on Vaccine Titers by W. Jean Dodds, DVM