Many of us have had experiences with pet owners who refuse vaccines for their pets. These owners will offer a variety of reasons for their resistance, or sometimes no reason at all. Up until now, we have only had anecdotal evidence of this trend. Now for the first time, researchers have started to quantify vaccine hesitancy in dog owners.

Matt Motta, PhD, assistant professor of health law, policy, and management at Boston University School of Public Health; Gabriella Motta, VMD, associate veterinarian at Glenolden Animal Hospital; and Dominik Stecula, PhD, assistant professor of political science at Colorado State University, recently conducted a study on canine vaccine hesitancy (CVH) and some of its causes and effects.

The Mottas, brother and sister, spoke with me and shared their motivation for conducting this research. They report that all three co-authors have been “aware for years” that some dog owners don’t want to vaccinate their dogs.

From a campfire to cross-disciplinary research

Matt Motta, a researcher who has studied vaccine hesitancy in humans, and Gabriella Motta, a small animal veterinarian working in the trenches, recall sitting around a family campfire, trading “horror” stories from work. The subject of vaccine hesitancy came up.

Seeing that there were a lot of anecdotal similarities between their experiences with humans and animals, they kept talking about it. They continued that conversation “for a while,” Matt Motta said, comparing human vaccine hesitancy, particularly to the Covid-19 vaccine, to pet owners who refused to vaccinate their dogs.

But unlike in human medicine, the authors noted that no one had made an effort to quantify vaccine hesitancy in animal owners or determine the effects of this behavior on public health and health policy. So, they set out to do just that.

Factors of vaccine hesitancy

According to Matt Motta, their findings suggest that the same factors (political party, level of education, promotion of vaccine misinformation, and others) that make people less likely to have a positive opinion of vaccines for themselves, negatively affect their opinions on vaccines for their dogs.

This has been termed the “vaccine spillover effect,” whereby views toward one vaccine affect views toward other unrelated vaccines. Matt Motta wrote in another article that negative attitudes toward the Covid-19 vaccine may be spilling over into attitudes toward mandatory vaccination of children for other diseases, for example.

The rabies example

The researchers documented that, among the dog owners surveyed, 37% found canine vaccines to be unsafe; 22% found them to be ineffective; and 30% found them to be unnecessary. Fifty-three percent of dog owners agreed with at least one of these positions.

In terms of the canine rabies vaccine specifically, 84% of dog-owning respondents indicated that they were sure that their dog was up to date with their rabies vaccine. Forty-eight percent of respondents opposed mandatory rabies vaccination for pets, believing that the decision to vaccinate should be left to the pet owner.

The sequelae of vaccine hesitancy in pet owners can be detrimental to both human and animal health, particularly in the case of rabies vaccination. Whereas transmission of rabies from dogs to humans can be largely prevented by vaccinating at least 70% of dogs in high-risk areas, the study authors report, areas where this 70% canine vaccination threshold is not met typically can see thousands of human deaths from rabies each year.

Opposition to rabies vaccine laws may contribute to relaxation and/or eradication of such laws in some municipalities, increasing the public health risk in those areas.

Vaccine hesitancy and veterinary wellbeing

CVH also likely negatively affects the mental wellbeing, stress, and burnout levels of veterinary professionals, the researchers add. When pet owners disregard our expert advice to vaccinate their pets, the veterinary professional-client relationship can be damaged.

Conflict can also arise when unvaccinated animals are denied services such as boarding, surgeries, or nail trims to protect other animals, especially when veterinary staff and owners don’t understand or agree with the decision. Veterinary professionals who do handle unvaccinated animals can experience increased stress as they worry about exposure to themselves, their co-workers, and their other patients.

The Mottas agree that their study is just the beginning. Future work will measure feline vaccine hesitancy, collect more qualitative information about why pet owners are hesitant to vaccinate their pets, and try to document correlations between infectious disease trends and vaccine hesitancy in pet owners.

They also plan to study any proposed changes to rabies vaccine laws in the past 40 years to determine how often changes have been made, why the changes were proposed, and what the effects of those changes have been.

Is vaccine hesitancy a messaging problem?

When asked if vaccine hesitancy in pet owners shows a messaging problem in veterinary clinical practice, the Mottas each relayed their own experiences. Matt Motta responded that, in his research with human vaccine hesitancy, “one of the best predictors of how people feel about medicine is how people feel about science and experts.” These feelings can be affected by a number of factors, including political party affiliation and religion.

Gabriella Motta added that it is important at the clinical level to try to understand why any individual client might not want to vaccinate. While this won’t always be the case, there may be some opportunities to refute any misinformation and help increase client trust so that they reconsider vaccination.

She also points out the importance of discussing vaccines and preventive care with clients who only tend to seek veterinary care when their pets are sick. These clients may not always be aware of what their pets are missing from vaccinations, and they may not understand the value of preventive care in their pets’ lives.

As these studies continue, the Mottas hope that others will join them in looking for solutions to protect animal and human health, while fostering trust between pet owners and their veterinary teams.

Further reading

Sick as a Dog? The Prevalence, Politicization, and Health Policy Consequences of Canine Vaccine Hesitancy (CVH)
https://osf.io/preprints/socarxiv/qmbkv/

Is partisan conflict over COVID-19 vaccination eroding support for childhood vaccine mandates?
https://www.nature.com/articles/s41541-023-00611-3

Emily Singler, VMD, is a 2001 graduate of Penn State University and a 2005 graduate of University of Pennsylvania School of Veterinary Medicine. Her career in veterinary medicine has included experience in shelter medicine, private practice, and as a relief veterinarian. She currently works as a veterinary writer, consultant, and mentor and enjoys writing for both pet owners and veterinary professionals. Her writing interests include public health, preventive medicine, the human-animal bond, and life as a working mom. She is the author of Pregnancy and Postpartum Considerations for the Veterinary Team, which is being published by CRC Press in November 2023 and is available for preorder now at www.emilysinglervmd.com.

Photo credit: © smrm1977 E+ via Getty Images Plus 

Disclaimer: The views expressed, and topics discussed, in any NEWStat column or article are intended to inform, educate, or entertain, and do not represent an official position by the American Animal Hospital Association (AAHA) or its Board of Directors.