Protection Dogs In Texas Heat
Heatstroke And The Working Dog

Dogs barely sweat, so as the air warms they cool mainly by panting, and humid air or hot ground takes that away fast. In UK primary-care data, most heat illness struck dogs that were exercising, not dogs lying in the shade. If a dog overheats, stop, start cooling it where it is with cool or cold water and moving air across it, then drive to a vet and keep cooling on the way. For a working dog the real prevention is unglamorous: train at the cool end of the day, build heat tolerance slowly, and never leave a dog in a parked vehicle without the engine and air conditioning running and the vehicle in sight. If you cannot meet both, take the dog with you or leave it at home.

The rest of this page is the reasoning behind those sentences, because a buyer who understands the mechanism makes better calls on the day than one who memorised a temperature. We are trainers, not veterinarians. The figures and thresholds below are from the sources linked. The first-aid list is our own synthesis of them, with each step marked as source-backed or as a general precaution. It is not veterinary advice, and your own vet’s instruction beats anything on this page.

In mild weather, the skin does most of the work. A 2017 review of canine heatstroke by Bruchim, Horowitz and Aroch, in the journal Temperature, puts it at more than 70 per cent: under normal conditions most of a dog’s heat leaves by radiation and convection from the body surface. That route depends on the air being cooler than the dog. As air temperature climbs toward body temperature, that route narrows, and evaporation from panting becomes the main way out.

Then panting is all that is left. Texas A&M’s veterinary college explains in its summer heat advice that dogs “can only sweat through the bottoms of their feet, so they must expel heat by panting.” Panting works by evaporation, and evaporation depends on how much water the air already holds. The Bruchim review gives the thresholds: above about 35 per cent relative humidity panting becomes progressively less effective, and “when the relative humidity is >80%, this body cooling mechanism in dogs is negated.” Texas A&M puts its line at about 85 per cent, above which “evaporative cooling is almost totally inhibited.”

Which route closes depends on where in Texas you are. The wet Gulf air is covered on our Houston page and the dry desert air on our El Paso page. In our view, not a measured finding, North and Central Texas are the harder places to judge, because humidity there swings within a week and the same thermometer reading can mean a different dog on Tuesday than on Friday.

The forecast number is not the dog’s number. The heat index on your phone combines air temperature with humidity for a person in the shade. The National Weather Service says so plainly on its heat index page: the chart values are for shady locations, and direct sunlight can raise them by up to 15°F. A dog working on an open field at ten in the morning is in that sun, a foot or two above ground that has been heating since dawn, and doing physical work in a coat. Direct sun means the number on your phone can understate what the dog is working in.

Heat illness in dogs is mostly about exertion rather than weather. We set out the primary-care evidence for that, and the case that coat length is not the deciding variable, in our comparison of the Malinois, Dutch Shepherd and German Shepherd, so we will not run the same figures again. The working-dog evidence is narrower and blunter. Reporting on a 2024 study at the Penn Vet Working Dog Center, the University of Pennsylvania states that “heat-induced injuries are the most common non-traumatic cause of death for law enforcement and military dogs.” That is the closest published population we know of to a trained protection dog. It is worth knowing what kills them, too. The 2020 Animals paper behind our breed comparison cites a study of US civilian law enforcement dogs. In that study heat-related illness was the second most common cause of traumatic death, and three-quarters of those heat events were triggered by confinement in a vehicle.

The rest is exertion, and here we are giving our own view as handlers rather than anything a study measured. Working lines are selected to keep going when the work stops being comfortable. That is the trait you are paying for, and in July it is the trait that can hurt them. A good working Malinois with a sleeve in front of it is not going to quit because it is getting hot; not quitting is what it was bred for. So the dog cannot be the one who decides the session is over. You have to be.

One detail from the Bruchim review is worth sitting with. Highly trained military working dogs often reached core temperatures above 42°C (about 107.6°F) after strenuous work without clinical or laboratory signs of heatstroke, which the authors attribute to acclimation. In the same review, most heatstroke events in those dogs happened during their first year of training, after a move from a cool climate to a very hot one. The same temperature that a conditioned, acclimated dog tolerates can injure one that arrived in June. That is the next section.

Texas A&M’s line on this is short: “pets that aren’t acclimated to hot environments will heatstroke more easily.” The Bruchim review describes acclimation as a time-dependent process that expands the body’s temperature regulatory range, and shifts the point at which heat starts to injure. Neither source gives a number of days for a dog, and we have not found one we trust, so we will not invent one. What follows is who is likely to start the summer with the least of it.

A dog that has just moved here. A trained dog bought from a breeder or kennel in a cooler state and flown or driven to Texas in summer is the military first-year pattern in miniature. If you are buying from out of state, the timing of delivery is a real question to raise, and our guide to buying a protection dog from another state covers the rest of what changes with distance.

Indoor dogs, and every dog in spring. Our view as handlers, not something the sources measured: a dog that spends its days in air conditioning has had less heat practice than one that works outdoors, and a dog that has had a cool winter is less conditioned than in September. Build volume gradually from spring, so the dog is already working in warm air before the first truly hot week rather than meeting it at full volume. A newly delivered dog in its first weeks is also under the stress of a new home, which is part of why the first ninety days should be light on demand regardless of the month.

Through the summer itself. Two published findings shape how a session should end. A 2024 canicross study found that in 24.4 per cent of cooling profiles a dog’s temperature was still climbing in the first five minutes after it stopped running. Our reading of that: the end of the bite work is not the end of the heat load, and the dog needs shade, water and watching before it goes into a crate. And Hudak’s paper, citing an earlier source, says “a widened tongue and heavy panting indicate the dog is working hard to maximize air circulation to try to stay cool.” Treat a widened tongue and heavy panting as a signal to stop, whatever the plan said. When to train depends on your part of the state, and the regional pages above cover that. How much summer work a particular trained dog can drop without losing it is a question for your vet and your trainer, who know the dog.

The authors call heat-related illness “a progressive rather than a static disorder”, and that is the practical lesson. The grade is not a fixed diagnosis. A mild dog left working, or put in a hot vehicle, can become a moderate one. The same paper says any dog “with a temperature approaching 41 °C should be actively cooled as a matter of urgency” — about 105.8°F. The Bruchim review defines heatstroke as a core temperature above 41°C with central nervous system dysfunction, and puts the mortality rate around 50 per cent, “similar to that of human heatstroke victims.”

A thermometer helps, and a handler who works a dog hard in summer should own a digital one and know the dog’s normal resting reading. But read the dog first. A dog wandering, stumbling, ignoring commands it knows cold, or staring through you is showing you the neurological signs that sit in the severe grade, and none of that waits for a number. The reverse matters too: the military dogs above ran hot without harm because they were conditioned, so a high reading in a fit dog that is alert and recovering is a reason to stop and cool, not to panic.

The sources disagree about water temperature, so here is the disagreement. Texas A&M’s 2020 advice is to wet the dog “with cool (not cold) water”, put a fan on it and get it into air conditioning on the way to the vet. A 2019 U.S. Army article on working-dog heat injury tells pet owners to use towels soaked in lukewarm water. The same article describes military handlers doing something colder with their working dogs: cold water under the arms, along the undercarriage and on the paws for milder cases, and in severe cases ice sheets packed against the groin, armpits and neck, followed by IV fluids before transport to a vet. So the cool-not-cold advice is aimed at pet owners; the working-dog practice in that article is cold.

The newer research goes further. A 2023 study of British primary-care records in Veterinary Sciences looked at 623 heat-illness events. In 341 of them the notes recorded something about cooling, and of those 341, only 74 (21.70 per cent) had been cooled before the dog was taken to the vet. The commonest method recorded was wet towels, at 51.31 per cent. It traces the old “tepid only” advice partly to an earlier laboratory study in which some dogs died on immersion in ice-cold water, calls the worry that cold water would raise temperature through constricted vessels and shivering contrary to extensive evidence, notes that current guidelines recommend cold-water immersion and evaporative cooling, and argues the message “cool first, transport second” should be widely promoted. The same paper is careful in two ways: it notes concerns about cold-water immersion for a dog with neurological or cardiovascular compromise, and that evaporative cooling is often preferred in hospitals, and its records could not show how well any method actually worked. The 2024 field study of dogs at canicross races, in the Journal of Thermal Biology, found cold-water immersion cooled dogs effectively with no dog becoming hypothermic, and that in 24.4 per cent of the cooling profiles the dog’s temperature was still climbing in the first five minutes after it stopped running.

Our reading, for what a non-veterinarian’s reading is worth: the cold-versus-cool argument matters far less than the gap between cooling and not cooling, and in Hall’s records a large share of dogs were not cooled before transport. So the order this page uses is the one Hall’s team argues for: start cooling where the dog is, with cool or cold water, then drive and keep cooling on the way, as Texas A&M describes. If someone else can drive, one of you cools the dog the whole way. Ask your own vet, before summer, which method and order they want for your dog, so you are not deciding it at the side of a field, and follow them over us.

Texas A&M’s rule is the one to remember: if the pavement is too hot for you to touch, it is too hot for your dog. The numbers behind it come from unusually close to home. In 2020 a University of North Texas geographer, Paul Hudak, measured ground temperatures at 30 points along a suburban street used for dog walking about 35 miles north of Dallas, at 8 a.m. and 4 p.m. on a June day and an August day.

With the afternoon air at about 95 to 97°F, the hottest surfaces reached 151.1°F. The median for tar patches at 4 p.m. on the June survey was 140.3°F. Tar was hottest, then chip seal, then concrete, then grass, every time, and afternoon temperatures were significantly higher than morning ones for every material. The paper notes that mammalian skin cannot tolerate lengthy exposure above 111°F, and that dark, dry, bare surfaces were the worst. In the morning surveys, tree canopy shaded most of the measurement points; by 4 p.m. very few were.

The second half of the study is the more useful one for anyone with land or a trail. Along a lake trail in north-central Texas, on a day when the measured air temperature peaked at 92.5°F, brown sand reached 125.7°F at 4 p.m., while water and moist sand stayed the coolest surfaces all day. A dog on a creek bed or a stock-tank bank is choosing between some of the hottest and the coolest ground on the property inside a few feet, which is also why the water is a hazard of its own, as our guide to protection dogs on ranches and acreage explains.

Pads are the obvious casualty. The less obvious one is the heat that radiates up from the ground into a body carried a foot or two above it. A dog heeling along asphalt at four in the afternoon is standing over a surface far hotter than the air the forecast describes. The pavement habit we teach owners in North Texas is set out on our Dallas–Fort Worth page.

A parked vehicle heats fast, even on a mild day. McLaren, Null and Quinn, writing in Pediatrics in 2005, measured the interior of a dark sedan in full sun on 16 clear days with outside temperatures from 72 to 96°F. The study was written about children, but it measured the car, and the car heats the same whoever is inside. The interior rose an average of 3.2°F every five minutes, 80 per cent of the rise came in the first 30 minutes, and even on the coolest day the inside reached 117°F. On the days the windows were cracked an inch and a half, it made no meaningful difference to the rate of rise or the peak. Texas A&M’s figure for how quickly a car can become lethal is “as little as 15 minutes,” and its rule is to have the dog inside the vehicle with the air conditioning running whenever it is 85 degrees or more.

The engine-running habit has its own failure. A dog left in an idling vehicle with the AC on is safe exactly as long as the engine and the compressor keep running. We would not leave a dog that way for longer than we could see the truck.

After work, the vehicle can stop a dog from cooling. In the 2024 canicross study, dogs that were not put into a vehicle after running cooled more than those that were. Our inference is the obvious one: cool the vehicle before the dog gets in, and keep air moving around it on the drive. For a protection dog that usually means the crate is in the cab with the AC already running, not in a closed camper shell that has been in the sun since the session started.

Truck beds. Texas A&M advises that even below 85 degrees you should never put a pet in the bed of a truck. The college gives the rule without a reason. Our reasoning: a metal or lined bed in sun can run hot, and Hudak’s work shows dark dry surfaces get hottest, but nobody measured a truck bed.

Texas has a statewide rule, and it is narrower than people assume. Senate Bill 5 of the Legislature’s third called session in 2021 — signed on 25 October 2021 and effective 18 January 2022 — added a subchapter on the unlawful restraint of a dog to the Health and Safety Code. Under the enrolled text, an owner may not leave a dog outside and unattended on a restraint unless it has access to adequate shelter, an area that lets it avoid standing water and excessive waste, shade from direct sunlight, and potable water. “Inclement weather” in the definitions expressly includes extreme high temperatures. The restraint cannot be a chain, cannot carry weights, and must be at least five times the dog’s length or ten feet, whichever is greater. A knowing violation is a Class C misdemeanor, and Class B for a repeat conviction.

Two limits on what that means. First, it is about tethered dogs. A dog loose in a fenced yard or a kennel run is not on a restraint as the bill defines one, though other law may still apply, and the bill expressly leaves room for city rules that are equal or stricter. Second, its exceptions include a dog left in an open-air truck bed for the time reasonably needed to finish a temporary task. That is a statement about what is a misdemeanor, not about what is safe, and the vehicle section above is the answer to the second question. For a protection dog the statute is a floor so far below how the dog should live that it rarely matters — but it is worth knowing that shade and water for a dog left outside are written into Texas law.