Exploring the Benefits and Implications of Titer Testing for Canine Vaccination

1. Introduction

Although pet owners want to do what is best for their animals, the cost of vaccinating dogs and cats, especially dogs, has recently been brought into sharper focus. Vet bills are said to be one of the most costly aspects of pet ownership, second only to food. To keep that bill from being too big, it's not surprising that people would conduct internet reviews to see what other veterinarians in their area charge for the procedures they need. Research reveals that pet owners are apprehensive about the cost of vaccines, particularly when their pet is young and needs a variety of vaccines. Now is a good time to consider or study titer testing.

There is a great deal of ambiguity and potential conflict in the area of titer testing before administering certain monovalent vaccines, as assessed in interactions with the membership. One trouble area, for example, focuses on the use of titer testing for canine core vaccines. Titers are seen with suspicion by some veterinarians and they believe that the use of titers in such scenarios would primarily benefit only breeders or pet owners who do not trust science. It should be mentioned that titer testing is primary and sensible, but these different standpoints and the contradictions in the discussions should be explored. In recent years, numerous documents detailing the adverse effects of vaccinations have been issued. Concerns regarding annual core vaccines have arisen as research on the duration of immunity gaps in core vaccines shows that immunity lasts longer than the suggested period. It appears that titer testing and when or where to titers would be of great use in in-depth discussions with our policyholders.

2. Understanding Titer Testing

Titer testing is not nearly as well-known as it should be. It's evidence-based, cost-effective, and confined to no specific species or breed. Technically, we could theoretically blood-sample and titer-test everything from cats to cows. Imagine testing humans for their antibody levels in much the same practical way. But ultimately, despite the benefits, titer testing won't be thoroughly known and understood for many years to come yet. They'll surely get there one day.

Nonetheless, lest I prompt some bombous upheaval of the traditional veterinary industry methods, we're discussing this in relation to dogs. Specifically, we're talking about the use and practicality of titer testing for canine vaccinations.

A quick and oversimplified rundown of titer testing is this: it works to measure the amount of antibodies present in the blood at any given time. The antibody in question in this case fights off infectious diseases. What makes titer testing viable and effective enough to stand toe-to-toe with traditional vaccines is that over time, an animal's elevated antibody level declines. With each antibody comes a different rate of decline - some former virals (such as parvo and distemper) see their antibody levels slowly decrease, year by year, while others might drop past mere "clinically protective" within months. In addition, while titers are not foolproof (no test can be), animals in certain life stages may benefit more from a yearly measurement than another every three years. It depends on the animal, frankly.

3. Traditional Vaccination Protocols vs Titer Testing

Prevailing wisdom in traditional small animal veterinary practice has been primarily to vaccinate dogs based on the recommendations defined by vaccine manufacturers. Overall, small animal veterinary medicine values pet wellness and the prevention of infectious diseases. Consequently, puppies are vaccinated over a series of initial immunizations before being placed on an annual revaccination schedule. However, proponents of the titer testing methodology suggest that it be employed instead of the "one size fits all" approach used in traditional practice. These proponents argue that annual revaccination is redundant in animals that are fully immune.

Vaccination protocols for exotic animals often utilize the serological testing of vaccine immunity at regular intervals with subsequent revaccination only being performed based on the results of these tests. The similar use of titer testing for dogs could allow for a better understanding of each dog's immunological status. Once aware of a pet's immune status, a veterinarian could counsel a pet owner confused about revaccination to the current policy that an animal should have been vaccinated within the last three years to be considered fully protected. This information, however, may or may not change the owner's decision about revaccination on the basis of non-health related reasons such as boarding requirements, grooming contracts, and property leases.

Moreover, a negative titer does not categorically mean that the dog is susceptible to the virus which the vaccine is designed to protect against. The documented response rate to cell-mediated immunity (CD4 and CD8 T-lymphocytes) deviates from that of the humoral antibody response and is an area of canine immune physiology in need of further research.

4. Benefits of Titer Testing for Canine Health

There are many benefits of titer testing for animal health; practitioners can use titer testing to produce healthy animals that are not at risk of over-vaccination. Benefits of titer testing for veterinarian, clients, and animals include: 1. Titer testing contains the minimum amount of essential biologics to elicit protective immunity. 2. Titer tests can accurately assess the immunity of an animal at a specific point in time, providing a safe, accurate way to minimize the risks of over-vaccination. 3. Testing vaccines by titer allows for an appropriate immune response to a certain vaccine, often linked to age, size, breed, activity level, and/or other external factors; titer tests can produce more accurate immune responses than client-reported history. 4. Titer testing is cost effective and can save clients money on future vaccines while optimizing resources based on the protection of animals that the vaccines provide.

With the increasing incidence of tremor anxiety, epilepsy, allergies, and cancer in animals, some veterinarians are seeking more effective practices. Few veterinarians use titer tests, so cases of over-vaccinated trevors are rare. Some practitioners have reversed the practice of treating wild animals. However, the prevention of pre-vaccination problems has direct and indirect benefits for veterinarians. With the help of titer testing, some veterinarians reduce unnecessary stress, vaccination, and consulting fees. Testing the titer supplements may cost less than the resulting vaccine. Testing the local anesthetic product line helps practitioners provide antimicrobials while synchronizing your immune response. A sensitive, pregnant conductor can sleep without worrying about titer testing to protect the conductor and fetal health from the side effects of TPO vaccines.

4.1. Reduced Over-Vaccination Risks

An undeniable benefit of titer testing of antibodies is to inform the clinician and dog parent that vaccination is unnecessary because the dog is already immune - a 'done' titer. "Done" titers mean that separate clinical appointments, a separate set of adverse effects, and unnecessary serological monitoring do not need to be done for a vaccinated dog. Titer testing prior to vaccination is also preferred if a dog has been found to already have protective antibodies. In this instance, repeating their vaccine dose will only result in a self-limited rise of their titer, as the newly administered antigens get sequestered by pre-existing antibodies prior to the re-activation of a new wave of vaccinal immunity.

Although considered unfounded 'goodwill' at best or negligent care at worst by some vaccine scholars, evidence and scholarly opinion at large note the reduction of negative outcomes associated with not only anti-germane antigens like particularly leptospirosis, but especially so with core vaccinations, such as rabies and distemper. Unnecessary immunostimulation can result in adverse effects and even immune-mediated diseases in hosts who over-vaccinate, which is quantitative over time and imparts animal side effects from being vaccinated must be continually immunostimulated - cumulative among and within veterinary vaccine types. For example, most core diseases of canine and feline pets require only one- or at most two-dose vaccine regimens, as demonstrated by 'sterile immunity' of vaccinees in major challenge trials for vaccine registration.

4.2. Cost-effectiveness and Resource Allocation

Titers can also provide an alternative to vaccination altogether, which may be particularly beneficial to pet health since it allows avoiding unnecessary booster vaccinations. This may seem paradoxical, since it may seem that the resources used for titers and the costs of the test would entirely outweigh any benefits of avoiding the occasional booster vaccination. However, for animals in good health, titers and vaccines are usually administered at the time of other veterinary visits, and so veterinary costs associated with vaccination are similarly minimal. Unfortunately, the cost of veterinary care is currently considered to be a barrier for the proper vaccination and medical care of pets. As such, avoiding unnecessary visits by reducing the number of vaccinations that an animal receives can reduce the number of times that pet owners encounter veterinary bills, which may have benefits for pet health and client satisfaction. This also would be expected to have benefits for veterinary hospital flow, as fewer animals will be needing appointments for vaccination, and to optimize the use of veterinary-specific resources, such as vaccine inventory, staff time dedicated to vaccination-related questions and informed consent, and freezer space.

5. Implications and Considerations

There are a number of implications associated with the incorporation of titer testing into canine vaccination protocols. Regulatory and legal aspects, as well as burden of proof, play a significant role in veterinary medicine. Titer testing is regulated differently in each state, and results are tested at varying intervals by state animal health officials. Likewise, legal and policy requirements of vaccination differ between states and between states and municipalities. While vaccination policy generally has mimicked industry and client convenience, current legal requirements are based on significant, well-documented evidence for risk and disease control. Educational campaigns for pet parents, veterinarians, technicians, and government officials are necessary to foster compliance with reduced vaccination frequencies or titer testing-only protocols. This will also require the development of guidelines for interpretation and recommendations concerning protective titers in dogs.

Barriers to change most significantly affect veterinarians. As data are collected and algorithms are developed, the related costs and liability must be considered for veterinary use. New thinking may change current documentation and notification requirements, and it would be anticipated that proof of immunity potentially decreases some legal/moral liability defense. Memoranda in state regulations sometimes make vaccine laws inappropriately prescriptive. The American Veterinary Medical Association (AVMA) has proposed mettle, negligence, and mal vet is laws be preferred to extended rather than denied scorning of state statute. An informal survey found 57% of veterinarians participating have titers for protection against the progress of immunity to four-day diseases. The need for further study on the effectiveness of titer testing for pet health is recognized.

5.1. Regulatory and Legal Considerations

In some countries or states, titer results are not considered legal proof of immunity, and the vaccination frequency is sometimes regulated by law.

General vaccination to protect public health is a collective application, while titer testing for ensuring immunity is an individual diagnostic application.

5.2. Educational and Awareness Campaigns

Given the extreme variation in knowledge about titer testing among veterinarians, the current U.S.-based initiative to develop educational resources may be in its infancy internationally, likely hindering broader use of titer tests to monitor vaccine response in dogs. Titer testing offers numerous benefits but can have potential implications at many levels. An education campaign targeting insights into the use of titer testing could involve developing strategies to educate several groups, including veterinarians, pet owners and caretakers, and dog trainers, as well as members of the general public. In terms of veterinarians, these strategies could include developing webinars, tips, and supportive documents to help practitioners inform their clients about the use of vaccine titers to monitor immune response.

Many pet owners involved in titer discussions demonstrate excitement, along with significant misconceptions about titer testing, and many express their desire to be informed and make better vaccinating decisions for their pets. This offers a terrific opportunity to educate the public via a larger marketing effort if some thought could be given on how to recruit these owners. Educational resources to assist professionals who serve as trusted sources of information on raising, training, and caring for dogs are another potential strategy, including dog trainers and pet store employees or advocates. Not to be overlooked is the value of sponsoring awareness campaigns through national and international dog and veterinary media platforms. Pet owners now have a unique opportunity in dog-day care circumstances, such as that offered by the 7,000 Play and Train program's Doggie Day Camps in the United States (U.S.), potential impacts of the non-vaccinated dog, including its likely high titer against one or more pathogens, being inoculated with more dead or inactivated organisms, could be addressed through education about relevant research and published information.

6. Future Research Directions

Some of the most pressing issues in need of additional research are identifying the correlation between titer levels and protection against disease in dogs. As discussed in Chapter 3, a few vaccines have suggestions in their labels for what may be considered a protective titer, but for many pathogens, this information is simply not available. Another area that needs more research is seroprevalence. We need accurate estimates of immunity in veterinary and shelter animal populations in order to understand just how many of our patients are truly underdeveloped and would actually benefit from titer testing. Also, large-scale longitudinal studies are needed in order to better understand the duration of immunity following vaccination and natural exposure to infectious disease. There may be some benefit to conducting some studies on a more basic biological level to further uncover some of the mechanisms of antibody response associated with natural infection and vaccination. The immunology of binding antibodies, protective antibodies, and duration of immunity is not fully understood, and likely won't be for some time; however, constantly advancing the knowledge base may one day provide a means to better evaluate protective immunity through binding antibody.

If titer testing becomes the standard of care in the United States, as it is in some other countries, there will be a great need for reference laboratories to provide these services and to also establish titer cutoffs that establish immunity in a dog. A good step to take next would be for the veterinary community to work with the operator of the KiSS system to get a feeling for the level of interest among veterinarians in titer testing. This information would be invaluable for organizations that provide continuing education to veterinarians in order to motivate course offerings on titer testing, and to provide members of this profession with the most accurate information.

7. Conclusion

The purpose of this essay was to explore the potential benefits and risks of titer testing for canine vaccination programs. Titer tests provide an accurate measure of a dog’s immunity status and pose a non-invasive, low-stress alternative to frequent vaccinations in the general dog population. Titer testing is a valuable tool for identifying overly concerned owners likely to own poorly vaccinated dogs with reduced immunity compared to their non-titer testing counterparts. An increase in the use of titer tests at the individual dog level could coincide with a trend toward fewer direct veterinary costs for dog owners and an increased focus on disease history and clinical examination during routine veterinary consultations. However, there is a potential downside to titer testing which must be acknowledged. The widespread use of titer testing could promote a trend away from control of the herd through population-based approaches and create an epistemic risk of increased cases of CDV, CPV/CCV, and CA titer risk in the general dog population at large. Although rare, the intrinsic risks associated with increased cases of clinical disease warrant the need for further discussion on this topic.

The introduction of titer testing has the potential to set the stage for fruitful investigation into naturally occurring mechanisms of long-term immunity in companion animals. Thus, the exploration of the benefits and implications of titer testing could serve a dual purpose; to chart the current climactic waters of canine vaccination and to foreground the future canon of canine vaccination. It is essential to stay abreast with novel informational technology, as new technology is likely to remain influential both in its own right and in what it will displace or call into question. Current US national canine vaccination guidelines call for vaccination against several viral diseases for which little to no titer correlation studies have been completed on the ability of that robust, long-term immunity. With titer testing for dogs becoming scientifically more accessible, more accurate, and more cost-effective, it is practical to explore this contentious issue before this technology becomes widespread.

References:

Khoury, D.S., Wheatley, A.K., Ramuta, M.D., Reynaldi, A., Cromer, D., Subbarao, K., O’Connor, D.H., Kent, S.J. and Davenport, M.P., 2020. Measuring immunity to SARS-CoV-2 infection: comparing assays and animal models. Nature Reviews Immunology, 20(12), pp.727-738. nature.com

Galipeau, Y., Greig, M., Liu, G., Driedger, M. and Langlois, M.A., 2020. Humoral responses and serological assays in SARS-CoV-2 infections. Frontiers in immunology, 11, p.610688. frontiersin.org

Moore, S. M., 2021. Challenges of rabies serology: defining context of interpretation. Viruses. mdpi.com

Moore, S. M. & Gordon, C. R., 2020. Measures of rabies immunity. Rabies. [HTML]

Janssens, Y., Joye, J., Waerlop, G., Clement, F., Leroux-Roels, G. and Leroux-Roels, I., 2022. The role of cell-mediated immunity against influenza and its implications for vaccine evaluation. Frontiers in immunology, 13, p.959379. frontiersin.org

Oberländer, B., Failing, K., Jüngst, C.M., Neuhaus, N., Lierz, M. and Möller Palau-Ribes, F., 2020. Evaluation of Newcastle Disease antibody titers in backyard poultry in Germany with a vaccination interval of twelve weeks. Plos one, 15(8), p.e0238068. plos.org

Khoury, D.S., Cromer, D., Reynaldi, A., Schlub, T.E., Wheatley, A.K., Juno, J.A., Subbarao, K., Kent, S.J., Triccas, J.A. and Davenport, M.P., 2021. Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection. Nature medicine, 27(7), pp.1205-1211. nature.com