Study finds voluntary head dunking cools dogs faster after exercise

A simple behavior, if trained ahead of time, may give veterinarians and handlers a faster field option for cooling overheated dogs after exercise. In a 2024 JAVMA study, researchers at the Penn Vet Working Dog Center found that voluntary head dunking into 22°C water reduced core body temperature more quickly than neck ice packs, a wet neck towel, or wet axillary towels in dogs with exercise-induced hyperthermia. It was also the only intervention that prevented the immediate post-exercise rise in temperature seen with the other methods. (pubmed.ncbi.nlm.nih.gov)

The work builds on a broader shift in heat-injury management toward rapid cooling as early as possible. The paper’s clinical relevance section explicitly reinforces “cool first, transport second,” reflecting current thinking that delays in cooling worsen outcomes in acute heat injury and can increase morbidity and mortality. As the authors discussed in AVMA’s Veterinary Vertex podcast, that principle is especially important because a dog’s internal temperature can continue to rise after exercise has stopped, making early field intervention potentially outcome-changing before veterinary care is reached. Earlier canine cooling research had already shown that water immersion can outperform passive cooling, even when the water is room temperature, but whole-body immersion isn’t always realistic in field settings or acceptable to every dog. (pubmed.ncbi.nlm.nih.gov)

In the new study, 12 working dogs completed a randomized crossover protocol between June 27 and July 24, 2023. Dogs exercised for up to 10 minutes and were stopped when core temperature reached 40.6°C or higher, or when they showed at least two signs of heat stress. Each dog then received one of four cooling methods: two chemical ice packs on the neck, a 22°C wet neck towel, 22°C wet towels in the axillae, or voluntary head immersion in 22°C water. The interventions were chosen with real-world use in mind, using supplies likely to be available in a first-aid kit or carried by an owner or handler on a long walk. All dogs eventually returned to baseline temperature, but the head-dunk group had the lowest mean core temperature in the first five minutes and over the following 35 minutes, and it was the only protocol to blunt the early post-exercise rise. (pubmed.ncbi.nlm.nih.gov)

The study’s authors were careful about scope. Their conclusion applies to trained dogs with normal mentation that can pause panting long enough to perform the behavior. In the Penn Vet coverage, senior author Cynthia Otto said the method could be “an invaluable tool” for preventing exercise-induced hyperthermia and heat stress, particularly in working dogs that may overheat in environments with limited cooling resources. The same coverage noted that heat-induced injuries are the most common non-traumatic cause of death for law enforcement and military dogs. In the AVMA podcast, lead author Sarah Parnes also emphasized that the motivation was broader than working dogs alone: pet dogs can also suffer serious, preventable heat injury, and owners may need practical steps they can use before they get to a veterinarian. (penntoday.upenn.edu)

Additional commentary suggests veterinarians should treat head dunking as one tool, not a universal answer. In a late-2025 dvm360 interview, Otto said dogs that are too hot to stop panting may not tolerate dunking and may instead need hosing, pool immersion, and veterinary care as indicated. She also said an unpublished follow-up study comparing head dunking with soaked towels has not, so far, shown the towel method to reproduce the same cooling effect. (dvm360.com)

Why it matters: For veterinary teams, the practical message is twofold. First, this is a potentially valuable preventive and first-response strategy for canine athletes, working dogs, and other high-drive dogs that predictably exercise in warm conditions. Second, it underscores the importance of anticipatory client education: if a clinic wants pet parents to use this technique safely, the behavior has to be trained before it’s needed, and clinicians should be clear about when it is and isn’t appropriate. Dogs with altered mentation, severe heat illness, or inability to pause panting should not be expected to perform a voluntary dunk and may need more aggressive cooling and immediate medical escalation. The study also speaks to lower-resource field situations, where handlers may not have air conditioning or large volumes of water available but still need a practical way to start cooling immediately. (pubmed.ncbi.nlm.nih.gov)

There’s also a broader clinical communication opportunity here. The study challenges some common field habits, like relying on localized neck cooling, by showing those options were less effective in the crucial first minutes after exertion. That doesn’t make towels or ice packs useless in every context, but it does suggest veterinarians should be more specific when advising pet parents, trainers, and handlers about what works fastest when whole-body immersion isn’t available—and should emphasize that post-exercise temperatures may keep climbing if no intervention is started. (pubmed.ncbi.nlm.nih.gov)

What to watch: Expect more data on alternative field methods, including colder versus room-temperature water, standing versus lying in a pool, and whether pouring water over the head or other modified approaches can help dogs that haven’t been trained to dunk voluntarily. Those results could shape more detailed heat-response protocols for general practice, sports medicine, and working dog programs. (dvm360.com)