Study finds head dunking rapidly cools dogs after exercise
A study highlighted by AVMA’s Veterinary Vertex podcast is putting evidence behind a simple behavior many working-dog handlers may find surprisingly useful: voluntary head dunking. In the 2024 JAVMA paper, Penn Vet Working Dog Center investigators reported that trained dogs who submerged their heads in 22°C water after exercise-induced hyperthermia cooled faster than dogs treated with neck ice packs, a wet neck towel, or wet towels placed in the axillae. It was also the only intervention that prevented the early post-exercise rise in core temperature. (pubmed.ncbi.nlm.nih.gov)
The work builds on a longstanding challenge in canine sports and working-dog medicine: dogs can continue heating up even after exercise stops, and field conditions often limit access to ideal cooling setups. The authors frame the study within the broader heat-injury principle of “cool first, transport second,” emphasizing that rapid cooling reduces morbidity and mortality. Older physiologic research has also shown that dogs can achieve selective cooling through structures associated with the nose, mouth, and head, which helps explain why targeting the head may have outsized effects on whole-body temperature. (pubmed.ncbi.nlm.nih.gov)
In the randomized crossover study, 12 working dogs exercised for up to 10 minutes and were stopped once they reached at least 40.6°C core temperature or showed at least two signs of heat stress. Each dog underwent all four cooling protocols, separated by at least 48 hours. According to the paper and Penn Vet’s summary, the head-dunk approach produced the lowest mean core temperature in the first five minutes after exercise, decreased temperature within the first 30 seconds, and maintained the lowest temperatures through the 40-minute monitoring period. All methods eventually returned dogs to baseline, but only head dunking blunted the immediate post-exercise spike. (pubmed.ncbi.nlm.nih.gov)
Researchers and industry media have focused on the method’s practicality. In interviews, Cynthia Otto said the technique had already been used at the Working Dog Center to help flush dogs’ eyes and noses, and the team was surprised by how strongly it affected post-exercise cooling. She said the water used was room temperature rather than ice cold, and described the likely mechanism as cooling highly perfused tissues in the head, mouth, and face while also allowing limited drinking. Otto also noted that the dogs were not asked to submerge their ears, to avoid filling the ear canals with water. (dvm360.com)
There are also important caveats. Otto told dvm360 that this is not a one-size-fits-all solution and should not be attempted in dogs with altered mentation or dogs so overheated that they can’t stop panting enough to tolerate the maneuver. She also noted that the group has not yet adequately studied brachycephalic breeds, and that the published work so far has centered on working-breed dogs such as Labradors and shepherds. That limits immediate generalization across all canine patients, especially those with airway compromise or different conformational risks. (dvm360.com)
Why it matters: For veterinarians, technicians, sports-medicine teams, and working-dog handlers, the study offers a more evidence-based way to think about field cooling. It doesn’t replace established emergency management for heatstroke, and it won’t fit every dog or every setting. But it does suggest that for selected dogs, trained voluntary head dunking may outperform several commonly improvised localized cooling methods that are easier to deploy than full immersion, yet may be less effective in the critical first minutes after exertion. That’s especially relevant for practices advising clients involved in agility, field trials, detection work, hunting, canicross, and other high-exertion activities where heat load can escalate quickly. (pubmed.ncbi.nlm.nih.gov)
The study has also drawn broader recognition. Parnes’ paper received a JAVMA award at AVMA Convention 2025, underscoring the profession’s interest in practical, field-ready heat-mitigation strategies. Meanwhile, Penn researchers have already signaled the next phase of investigation, including whether colder water, soaked towels applied to the head, or other substitute approaches can approximate the effect of a true head dunk. Early comments suggest the towel approach may not match dunking, but clinicians will need to wait for peer-reviewed publication before changing protocols on that basis. (avma.org)
What to watch: Expect follow-up data on water temperature, substitute head-cooling methods, and which patient groups are appropriate candidates, particularly as interest grows in translating this protocol beyond working dogs and into broader preventive guidance for pet parents. (dvm360.com)