Q&A: Tick prevention in dogs and cats—what’s changed and what to do now

Tick populations are expanding in both range and season, reshaping how veterinarians approach parasite prevention. In this Q&A, Susan E. Little, DVM, PhD, DACVM (Parasitology), discusses what’s driving the shift, how risk is changing in clinical practice, and what veterinarians should be telling clients about year-round protection.

Editor's note: This dvm360 Q&A has been edited and consolidated from a verbal interview to better fit a written format while retaining the substance of the original conversation.

dvm360: What are the most important control strategies for protecting dogs from parasites?

Little: The most important control strategy is diligent attention to monthly parasite control. We've got to have protection in place, whether we're worried about fleas, ticks, intestinal parasites, heartworm, or tapeworms. For all of those infections, we have to be doing something, because otherwise nature will intervene. If we don't have tick control in place, the ticks will have their way. We know there's year-round tick activity in most places in the United States now, and the parasites have really upped their game in recent years. We as veterinarians have to come in with a plan in place to make sure patients are protected.

dvm360: How significantly have tick populations shifted in recent decades, and what is driving that change?

Little: The increase we've seen in tick populations in the past few decades has just been incredible. It was beyond what anybody's estimations were in terms of what the tick explosion was going to look like. We've got more ticks in more places. They've moved up in latitude [and] in altitude; the geographic spread has been phenomenal.

There are a number of reasons for that. We've certainly seen habitat change and increased wildlife host populations, which leads to increased ticks in more places. We've also seen the introduction and establishment of new species that have taken off because they found a welcoming environment with the habitat and the hosts there to feed them. And then we're dealing with the effects of climate change: earlier springs, later falls, milder winters.

On average, our winters are much milder than they've been historically, and with that increased temperature, the ticks have really taken advantage of that. It gives them more degree days to be out there finding a host, and if they find a dog or cat that's not protected with tick control, they're going to take advantage of that.

dvm360: What do veterinarians most need to understand about managing this growing risk in practice?

Little: One of the most important things veterinarians need to recognize is that we're dealing with different tick pressure than ever before. The tick challenges are higher. There are more species, more activity, and [longer] life stages. The risk is that much higher for our patients, and that's the challenging part. The good news is we have better tick control now than we've ever had. We have safe, effective, comprehensive tick control options that will protect dogs and cats from these challenges. We just have to get the 2 together [and] make sure pets are on tick control, because if they're not, the tick infestations and…infections that follow will happen.

dvm360: Does regular outdoor activity, such as daily walks, meaningfully increase a dog's risk for tick-borne disease?

Little: Dogs are definitely at high risk for tick-borne infections, and we see that in the serologic data and in the survey data that's been collected. We've seen an increasing prevalence of tick-borne infections in dogs, even with good tick control products and growing awareness about the problem. A dog not on tick control [who is walking] for even a short period of time or [is] allowed to roam in a wooded area is very likely to acquire a tick infestation and become infected. We're going to see seroconversion and potentially disease if we're not doing anything to change that situation.

dvm360: What should veterinarians be communicating to clients to help protect their dogs year-round?

Little: The first thing is that every dog is at risk. People have the impression that it's not their dog or not their neighborhood, but ticks are just about everywhere they can be. Every available habitat has been invaded by ticks, so it's almost a universal problem. Every dog is at risk of infestation.

The other thing we battle is the impression that ticks are only a problem when dogs go out hiking in a wilderness area. But they're in the backyard. They're in the understory right around the yard. They're at home. You don't have to go far to encounter ticks.

And then there's the impression that winter means no ticks. Ticks are happy to be out looking for hosts when temperatures are up to 50 ºF [or] 60 ºF. We need to make sure owners understand that winter is not always what winter used to be, and we can't predict when conditions will shift. Tick control needs to be on board for when the warm weather comes because as soon as it does, the melting snow provides a layer of humidity that keeps ticks actively questing for longer, because they don't…dry out. They're able to find a host, and with sunshine to warm them, they can be out there any time it's above freezing.