Science-Backed Strategies for Cooling Dogs from Dr. Cindy Otto
Sporting dogs cool more quickly and efficiently with active strategies, including the head dunk
The heat of the early season hunting can challenge even the fittest sporting dogs. High temperatures, humidity, and the relentless drive of these canine athletes create a perfect storm for heat-related injury.
On a recent episode of the Dogma Podcast, host Dr. Seth Bynum sat down with Dr. Cindy Otto—board-certified in both sports medicine and rehabilitation, as well as emergency and critical care—to discuss her team’s research on cooling working dogs.
As founder and executive director of the Penn Vet Working Dog Center, Dr. Otto oversees the health, conditioning, and performance of detection dogs, many of which trace their genetics to elite sporting dog lines. Her unique combination of clinical experience and scientific research offers practical, field-ready insights for anyone running a dog in hot conditions.
From Search & Rescue to Working Dog Science
Dr. Otto’s career began in emergency and critical care, but her experiences with search and rescue deployments—most notably during 9/11 and Hurricane Floyd—highlighted the lack of scientific understanding around canine occupational hazards. That need inspired the creation of the Penn Vet Working Dog Center, opened 2012. The center now serves as a hub for training, research, and education, raising detection dogs for law enforcement, conservation, and other working roles.
Understanding Exercise-Induced Hyperthermia
Hyperthermia simply means elevated body temperature brought on by the heat-generating work of exercise. In dogs, the normal body temperature range is about 100.5°F to 102.5°F. During intense exercise, temperatures can spike to 105°F within minutes. In a veterinary emergency room, that number would set off alarms—but in the field, it’s often a normal, transient response sporting dogs have to that level of exertion.
While high temperatures are part of the normal operating range of dogs, the danger comes when hyperthermia remains unchecked and progresses to:
Heat stress: Dog appears uncomfortable, may slow down or act less responsive.
Heat injury: Organs and tissues begin to suffer damage.
Heat stroke: Collapse, neurological signs, and about a 50% mortality rate.
Because dogs dissipate heat primarily through panting (and to a small degree via sweat glands in their feet), their cooling efficiency is limited—especially in humid environments. Dr. Otto emphasizes that body temperature alone is not enough to assess risk. Handlers should watch for:
Long, flattened tongue, drool, possibly along with thick, ropy saliva
“Squinty” eyes and ears pulled back
Wide-open, excessive panting with visible back teeth
Changes in obedience, stubbornness, like slower returns on retrieves or blinked birds, for example.
Seeking shade or appearing less focused in a dog that’s typically highly driven to keep hunting.
When these signs appear, stopping activity is critical—but rest alone may not be enough, as dogs continue to increase body temperature for a period of time after exercise ends. Waiting in the shade, Otto said, is a poor strategy for cooling dogs quickly.
Why Active Cooling Matters
Military working dog data show heat injury is the number-one preventable cause of death in dogs under five years old. Highly driven sporting dogs often work past the point of self-preservation, ignoring thirst and fatigue cues. That’s why handlers—not dogs—must make the call to cool them down.
Passive cooling, such as resting in shade, can take too long. Dr. Otto’s research sought to identify active cooling strategies that are fast, safe, and realistic in field conditions.
Study 1: Pools, Alcohol, and Passive Cooling
The team compared three methods:
Partial body immersion (standing or lying in a kiddie pool of 72°F water)
Alcohol-soaked towel under the feet
Rest in shade
Because dogs dissipate heat primarily through panting (and to a small degree via sweat glands in their feet), their cooling efficiency is limited—especially in humid environments.
Results: The pool method cooled dogs more effectively than alcohol or rest alone. Alcohol had only a modest effect and raised safety concerns—flammability, skin irritation, and minimal surface area cooled. The challenge with pools: some dogs resisted entering, and carrying one into the field (as you can imagine) is hardly practical.
Study 2: Four New Cooling Techniques
To find a more portable, dog-friendly option, Dr. Otto’s team tested:
Chemical ice packs around the neck
Cool, wet towel wrapped around the neck
Cool, wet towel in the armpits
Voluntary head dunk in a bucket of 72°F water
Each method lasted just 30 seconds. The surprise winner? The voluntary head dunk—by a wide margin.
While other techniques slowed temperature rise, a single head dunking session caused an immediate and significant drop, bringing body temperature below pre-exercise levels. In contrast, other methods allowed temperature to creep up for several minutes before gradually returning toward baseline.
Why Head Dunking Works
Infrared imaging shows the head, ears, and nose radiating the most heat after exercise. These areas act like the dog’s radiators, prioritizing blood flow to the surface of the skin to facilitate cooling with the surrounding air. Cooling these areas directly chills the blood circulating to the brain, which then helps cool the rest of the body. The water also evaporates from the facial area, adding another cooling mechanism on the surface of the skin.
In turn, panting remains more effective when the tissues in the upper airway are cooler. By lowering head temperature, dogs can continue to shed heat efficiently even in challenging conditions.
Training the Head Dunk
Dogs learn the behavior as a game. Using a sinking treat (string cheese works well) or a favorite non-floating toy, trainers gradually increase water depth:
Retrieve from a dry bucket.
Add ¼ inch of water.
Increase to 2 inches, then 4 inches.
Progress to a full bucket.
Some breeds take to it instantly—Dr. Otto had easy success with a food-motivated Labrador and a Kong-crazy Malinois, both of which went from food/toy in empty bucket to full-bucket dunk in just a few short sessions. More cautious dogs, like some border collies they trained, may require slower progression and positive reinforcement.
Field Application for Hunters
Fortunately, total body immersion (swimming or hosing dogs down) continues to provide a reasonable strategy when hunters can provide clean, relatively cool water to swim their dogs during a hunt.
But if water is compromised, dangerous, or otherwise unavailable, head dunking is an effective alternative. While head dunking requires a bucket or similar container, Dr. Otto believes it’s practical for many hunting scenarios, particularly if handlers carry collapsible water containers. The method is fast, well-tolerated, and repeatable mid-hunt.
Dr. Otto’s team is conducting additional research aimed to test the cooling efficacy of other common strategies:
Wrapping a cool, wet towel around the head for situations without dunking water.
Varying water temperatures (room temp vs. groundwater) in previous methods to find the safest and most effective range.
While Otto says total body immersion is the gold standard, she cautions that wetting dogs down as a cooling strategy can backfire if dogs are placed in unventilated crates immediately afterward—trapping humidity and creating a “steaming” effect. Ventilation is key to evaporation. We love and use the Gunner Fan Kit 2.0 to help promote ventilation and evaporation in the early season.
Beyond Cooling: Other Benefits
In addition to reducing core body temperature, head dunking may also serve as a performance enhancement or first aid strategy:
Hydrate nasal passages for better scenting
Serve as a first-aid tool to clear nasal or eye irritants
Assist in decontamination after exposure to harmful substances
Take-Home for Handlers
Early recognition of heat stress signs, promptly stopping activity, and active cooling are essential to preventing heat injury in sporting dogs. Dr. Otto’s research offers a new, field-friendly tool: train your dog to dunk its head in water on command. It’s quick, effective, and—unlike many interventions—enjoyable for most dogs once trained.
As the season heats up, common sense and fresh, clean water are your best cooling resources. However, a bucket, some cool water, and a well-conditioned dunking dog might be your best insurance policy against a heat injury in a pinch.
