B’LYME-y! Should I advise vaccination for K9 Lyme disease to my clients or not?

By Michelle Evason, DVM, BSc, DACVIM (SAIM) 

Vaccination for canine Lyme disease (either ‘for’ or ‘against’) can be a hot topic, particularly in the current vaccine hesitancy era. Unfortunately, along with other aspects of Lyme borreliosis management in dogs and cats, it’s also a topic lacking clear evidence- and expert-based consensus.^{1a, 1b} 

What is the research (‘evidence’) on Lyme vaccination?

One 2018 publication looked at the efficacy of Lyme vaccination through the lens of systematic review.² This work was performed to try and provide veterinarians (and pet-owners) with a much-needed evidence-based assessment of Lyme vaccination in dogs. 

Initially, and, as with many systematic reviews, the researchers began their study identification process with many articles (n =1570) that looked like they might help guide decision-making on Lyme vaccination, i.e., to vaccinate or not…that is the question …. 

But, using the standardized study inclusion (and exclusion) criteria, the authors ended up with only 16 publications that met their review standard. These 16 works on Borrelia burgdorferi (the agent of Lyme disease) vaccination included: 3 observational studies (the most current dated 2005), and 13 challenge studies, with only 5 of these 13 (38%) done in the past 10 years, and all done in young dogs (< 18 m of age). 

So…should we (or should we not) consider canine Lyme vaccination effective?

The researchers concluded that the summary of evidence suggests that vaccination is effective at reducing the risk of Lyme disease related clinical signs (lameness, anorexia, fever) in vaccinated dogs vs. unvaccinated dogs.²

However, the study also raised several concerns regarding items frequently assumed in Lyme research. This included questions like, were the ticks used in these studies actually infected with B. burgdorferi?, were dogs seronegative for B. burgdorferi prior to the study starting?), and perhaps most importantly (and admittedly this is my question not the researchers…), are these studies relevant for current (on-market) vaccines? i.e., have vaccines changed over the years? And if so, how, in terms of efficacy and safety?). 

Additionally, there was only one observational study included in the review that looked at Lyme disease clinical signs as associated with vaccination. As the researchers quite rightly point out, this lack of information on clinical signs (individual or clumped together) and/or the duration or severity of the dog’s clinical signs and impact of vaccination on these… is what is key for those of us attempting to make recommendations on vaccination to pet-owners based on dog risk. 

Ultimately, many important questions were raised with this research.² And these queries have likely helped raise awareness regarding the lack (and limitations) of studies on canine Lyme disease and what is needed to address this ongoing concern for veterinarians and dog-owners, particularly those in Lyme endemic and emerging regions.³ 

Sadly, this still leaves many of us with our original question on Lyme disease vaccination unanswered (and dog-owner recommendations unsupported), with any formal evidence-based process or clear consensus guideline.^1-2

Are veterinary clinics in the US vaccinating dogs for Lyme disease?

Sort of…one recent US study highlighted that even in Lyme disease endemic states, median clinic canine Lyme vaccine uptake was only 52%.⁴ The study also revealed wide variation in dog vaccination between veterinary clinics, even in similar states, with respect to Lyme vaccination, e.g., one clinic in PA with vaccine uptake of 94% and another clinic in PA with 0%.⁴ 

Dog-owner communication on Lyme vaccination

Despite a lack of clear consensus on Lyme vaccination in dogs, many specialists and veterinarians advocate for vaccination as part of a multi-pronged approached to Lyme disease risk reduction.^1b 

If you (your clinic) elect to recommend canine Lyme vaccination, communication to clientele may be made a bit easier with the following tips, talking points, and resources:

1. Recognize that many dog owners have concerns around safety of vaccination and ‘vaccine hesitancy’ related to this.⁴ Acknowledge these concerns and ask if you can provide your educated opinion and recommendations.
2. Reach out to vaccine manufacturers regarding the research, design, effectiveness, and quality assurance of their products. Review and request manufacturer vaccine safety and efficacy research data to potentially utilize in pet-owner conversations.
3. Address misunderstanding that some pet-owner may have regarding what vaccination can (and cannot achieve), i.e., vaccination does not protect the dog against all vector-borne pathogens. 
4. Communicate to clients that multi-modal prevention strategies for tick-borne pathogens are needed to reduce risk of tick-borne disease (Lyme and others).^1b This means using tick checks and veterinary approved tick prevention products. 
5. Address ‘One Health’ considerations, i.e., tick risk for the ‘two-legged’ family members in addition to the ‘four-legged’, and dogs as disease sentinels.^1a,1b
6. Use trusted resources around vaccine and risk communication, along with fear-free tactics. A few great resources include:
   1. AAHA website: https://www.aaha.org/your-pet/pet-owner-education/ask-aaha/Pet-Vaccination/
   2. Lifestyle-based Vaccine Calculator: https://www.aaha.org/your-pet/pet-owner-education/ask-aaha/Pet-Vaccination/
   3. Fear Free: https://fearfreepets.com/about/what-is-fear-free/?gclid=EAIaIQobChMImIeDyNi07AIVxsDICh1RVgdUEAAYASABEgLjXPD_BwE)

References

1.a. Littman^a MP, Goldstein RE, Labato MA, et al. ACVIM small animal consensus statement on Lyme disease in dogs: Diagnosis, treatment, and prevention. Journal Veterinary Internal Medicine 2006; 20:422-434.

1.b. Littman^b MP, Gerber B, Goldstein RE. ACVIM Consensus update on Lyme borreliosis in dogs and cats. Journal Veterinary Internal Medicine. 2018;32: 887-903.

2. Voyt NA, Sargeant JM, MacKinnon MC, et al. Efficacy of Borrelia burgdorferi vaccine in dogs in North America: A systematic review and meta-analysis. Journal Veterinary Internal Medicine. 2018; 1:1-14.

3. Companion Animal Parasite Council (CAPC) website, as accessed April 2022:  https://capcvet.org/articles/2022-forecasts/

4. Malter KB, Tugel ME, Gil-Rodriguez M, et al. Variability in non-core vaccination rates of dogs and cats in veterinary clinics across the United States. Vaccine. 2022. 11;40(7):1001-1009.