By Krista Halling DVM CCRP DAVCS
Summertime adventures with your dog can be incredibly rewarding, yet it’s crucial to be aware of the dangers posed by overheating. These conditions can escalate rapidly, having potentially fatal consequences for your canine companion. Let’s look at what heat stress and heat stroke are, the signs to watch for, and the initial treatment steps to take if your dog is affected.
How dogs keep themselves cool
A dog’s body, like that of a human, regulates its temperature much like a thermostat. When the core body temperature gets too high, physiological and behavioural mechanisms kick in to try to cool the body temperature back within the optimal range:
Panting
Blood vessels in the dog’s tongue dilate, bringing heat from the body into the tongue, much like a car’s radiator. Panting is rapid shallow breathing which forces air over the hot tongue, causing heat to dissipate through convection and evaporation.
Most dogs didn’t take high-school physics yet they’ve managed to develop a pretty efficient cooling system. Put simply, for those curious, in this case convection is when air movement takes away heat molecules like panting or a nice breeze; evaporation is when water uses body heat to turn from a liquid to a gas state; and radiation is when heat leaves a body because the ambient air temperature is lower.
Heat loss through skin
Regions with a large surface area such as the torso, a hairless belly, and large ear flaps also provide heat dissipation through convection and radiation. This is why hot dogs like to splay out frog-legged on a cool floor.
Sweating
Dogs lose a bit of heat from sweat evaporation through their footpads.
Shade-seeking
When a dog feels too hot, it will inherently look for a shady area or retreat to air conditioning.
Water-seeking
If they need to cool down, water-loving dogs will be quick to look for a stream, lake or even a puddle to lie down in.
Overweight dogs, senior dogs and dogs with respiratory or cardiac conditions are all at higher risk of overheating.
What is “overheating”
Overheating, also called “hyperthermia”, is defined as a body temperature above a dog’s normal range (38.2-39.5°C; 101.5-102.5°F). Overheating results from a dog’s body heating up faster than its ability to cool itself off, and is further defines as:
1. Heat Stress
This is the first state occurring when a dog’s body temperature rises above 39.5°C (102.5°F). It is the body’s initial response to excessive heat, and can progress to heat stroke if not treated promptly.
2. Heat Stroke
A severe form of hyperthermia, where the body’s temperature exceeds 40°C (104°F). This condition leads to life-threatening cellular damage and organ failure if not treated immediately.
Causes of heat stress and heat stroke
These factors put your dog at risk of overheating. Keep them in mind when you head on an adventure:
Hot/Humid Day
High temperatures, especially combined with high humidity, can overwhelm a dog’s ability to regulate their body temperature. Early in the summer or going to a tropical destination is an added concern, since dogs and humans take a while to acclimatize to temperature changes.
Exercising
Vigorous activity in hot conditions can elevate a dog’s body temperature very quickly. Keep a close eye on your dog for signs of heat stress and stop frequently in the shade for a break and a drink.
Insulating vests
Note that life jackets and high-surface-area harnesses trap heat, so be ready to remove them if your dog is showing signs of heat stress. Overheating can easily occur if your dog is wearing their life jacket while on a boat or on the beach during a hot sunny day. It helps to give them shade, wet them down or let them take a dip frequently. If staying wet isn’t enough to keep your dog cool, then you may be best to remove the life jacket when your dog’s not in the water.
Breed type
Brachycephalic breeds (e.g., bulldogs, pugs, boxers) and those with thick or dark-coloured fur are more susceptible to overheating.
Health status
Overweight dogs, senior dogs and dogs with respiratory or cardiac conditions are all at higher risk of overheating.
Inside a vehicle
Cars heat up like a greenhouse. The temperature inside a car can rise drastically and within minutes., even if parked in the shade and with windows open. never ever leave a dog in a parked vehicle on a hot day. Similarly, on a cold day, never leave a dog unattended in a car with the heater going.
Signs of heat stress in dogs
Early detection of heat stress can prevent the progression to heat stroke. Watch for ANY of these signs:
- Excessive panting
- Increased heart rate
- Drooling
- Mild weakness or lethargy
- Struggling during exercise
- Seeking shade or cool areas
- Fluid and electrolyte abnormalities
- Mildly elevated body temperature
Note that if exercising, your dog will not likely stop to tell you they’re in trouble. They might keep going until they drop. So it’s crucial to stop the activity and help your dog cool down if you see any signs of overheating.
Signs of heat stroke in dogs
If heat stress is not quickly treated, it can progress to heat exhaustion and then to life-threatening heat stroke. The signs become more severe:
- Heavy panting and difficulty breathing
- Intense thirst
- Bright red or pale gums
- Rapid or irregular heartbeat
- Vomiting and diarrhea
- Confusion, disorientation, stumbling or staggering
- Collapse or seizures
- Body temperature over 40°C (104°F)
What to do if your dog is overheating
- Get out of the heat! Immediately move your dog to a shaded or air-conditioned area.
- Temp check: Take your dog’s rectal temperature, if possible.
- Hydrate: Offer small amounts of cool (not ice-cold) water. Avoid forcing your dog to drink.
- Cool the body: Using cool (NOT cold) water, gently wet your dog using a hose, or placing them in a cool bath or lake (for up to 10 minutes). Keep their head above the water at all times.
• Place your dog in front of a fan. - Monitor body temperature: Use a rectal thermometer if available. Aim to gradually lower the body temperature. Do not cool your dog below 39.5°C (102.5°F). If you don’t have a thermometer, then stop cooling them once signs of heat stress (heavy panting etc) have resolved.
- Seek emergency care: Even if your dog appears to recover, it’s advised to seek veterinary care without delay, or at least phone the nearest vet clinic to ask if your dog should be seen. Heat stroke can cause life-threatening damage that isn’t immediately visible.
Preventing heat stress and heat stroke
Prevention is key to keeping your dog safe during hot weather adventures. Here’s a quick read on how to protect your canine buddy when it’s a sizzler out there: 8 Ways to Keep Your Dog Cool on Hot Days.
Understanding the risks and signs of heat stress and heat stroke can save your dog’s life. With the right knowledge and precautions, you and your furry friend can safely enjoy your outdoor adventures all summer long. Stay vigilant, stay hydrated, and most importantly, stay cool!
For more adventure ideas and tips on keeping your dog safe during summer adventures, explore our other articles on Dogpacking.com.
About the author
Krista Halling is a veterinarian board-certified by the American College of Veterinary Surgeons and Co-Founder of Dogpacking.com. She loves travelling and adventuring alongside her mini goldendoodle, River.
References
Mathews KA. (2017) Hyperthermia, Heatstroke and Malignant Hyperthermia. In Mathews KA (ed) Veterinary Emergency and Critical Care Manual (3rd Ed), 461-469.
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