Moving the Needle - Helping Pet Owners Through Vaccine Hesitancy

This episode is sponsored by Boehringer Ingelheim

In this episode of The Vet Blast Podcast presented by dvm360, Natalie Marks, DVM, CVJ, CCFP, Elite FFCP-V, joins host Adam Christman, DVM, MBA, to walk through what clients are actually afraid of when it comes to vaccinations, the safety evidence behind the reassurance, the language that keeps a conversation collaborative instead of adversarial, where core and lifestyle vaccine conversations should diverge, and more.

Below is a partial transcript, edited lightly for clarity.

Adam Christman, DVM, MBA: So what does the evidence actually tell us about vaccine safety in pets, and how do you help owners who are looking those things up weigh perceived risks against real risks of infectious disease?

Natalie Marks, DVM, CVJ, CCFP, Elite FFCP-V: The evidence tells us, which is no surprise, that vaccines aren't 100% risk free. Nothing is 100% risk free. But the evidence does tell us that they are overwhelmingly safe, and that the risk of those serious vaccine-associated adverse events that we think about is very low compared with the risk of the disease that we are trying to prevent.

There are a couple of safety studies that I want to just briefly mention. I think they're important for all generalists to be aware of. Not every client, of course, is going to want you quoting and citing studies in the exam room, but there are some that will, or at least [want you] sending it to them. There was a very large JAVMA safety study that was published in 2005. It was led by George Moore and colleagues out of Purdue, and it evaluated more than 1.2 million vaccinated dogs. They were looking at the amount of vaccine-associated adverse events diagnosed within 3 days of vaccination, and they found that that absolute number was 38.2 per 10,000 dogs vaccinated, or less than half of 1%. That is extremely small when we think about the grandiose nature of how many dogs are getting vaccinated. This study also showed that risk increased in smaller dogs and when more vaccine doses were administered at the same visit. So that does give us a really practical, evidence-based way to think about how to individualize the plan rather than just dismiss the owner's concern, but also to give reason behind why we might be suggesting splitting vaccines.

There was a newer JAVMA study that was published in 2023, and this had 4.6 million dogs—so triple the size—and it reinforced that our smaller body weights and breeds and multiple injections can be associated with increased adverse event reporting. It also showed that the adverse event rates for leptospirosis vaccines—and this is super cool because, as you know, I'm a huge lepto proponent as far as vaccination and prevention—that the rates for lepto were no greater than those for DHPP as well as rabies. That is such a key point, because leptospirosis vaccine is now core, yay! But they have historically carried that reputation of being more reactive. The current evidence does not support treating them as uniquely unsafe.

So when I'm talking to a [client] in an exam room, or educating in a lecture, or even just having a friend who calls me asking about this and speaking in my veterinary voice, I try to separate what I call the possible from the probable. Is a vaccine reaction possible? Of course it's possible. Mild lethargy, soreness, fever, or localized swelling—those are all possible adverse events. Allergic reactions can occur, but rarely. The real diseases, though, that we vaccinate against—so parvo, distemper, rabies, panleukopenia, feline leukemia, and leptospirosis—those are not theoretical. They exist. They can be severe. They can be super expensive to treat. They can be contagious. They can be zoonotic in some cases, and in other cases they are even life-threatening, as we know.

Specifically for cats, though, I think it's fair to acknowledge that there are concerns around adjuvanted versus the non-adjuvanted vaccines, and we can say that without overstating the risk. There was a 2023 European study that came out comparing that. Really what we need to take from this is that this does not mean every cat needs the same product or protocol. What it means, though, is that just like you said around this VIP individualized care, it's really important to have a thoughtful discussion around vaccine selection and individualized risk, especially with our cat caregivers that have concern around inflammation or injection site reactions.

A key point that we can kind of summarize is this: if you're in the exam room and you're really not even sure where to start, something like this might work for you, or make it into your own words. "My goal is not to give your dog or cat every single vaccine possible. That is not our goal. Our goal as a veterinarian is to protect your pet from the real preventable diseases using the safest, most appropriate protocol for them." So we want to be comprehensive, but we also want to tailor to the individual risk of that patient, and give that pet parent the information that they need to make the most informed decision.

Adam Christman, DVM, MBA: I love that, and these are great sound bites for the listeners tuning in to really steal, especially if you're starting out in practice trying to find your footing when you're having that conversation. Part of our job as veterinarians is really controlling the controllable, and preventive medicine is what we do day in and day out, and sometimes we take it for granted how often we're having these conversations.