J.C. Hardin, DVM
Overheating (hyperthermia) in your pet can lead to brain swelling (causing coma) with sometimes permanent brain damage (seizures, blindness), death of the lining of the intestine (which leads to stool bacteria entering the bloodstream causing septic shock, secondary kidney failure, etc.), bleeding disorders (DIC), and often death.
Treating heat stroke involves far more than just cooling a pet. Round the clock hospitalization for several days to a week or more, IV fluids, IV antibiotics, plasma transfusions, medications for brain swelling, oxygen therapy, frequent lab tests to assess proteins, clotting ability, electrolytes, etc. and more are needed, usually costing thousands of dollars.
Dogs do not sweat much at all, and certainly not enough to cool themselves. You may feel cool during a jog or while playing with your pet, but your dog is wearing a fur coat and not sweating like you are, making him / her much hotter.
Dogs cool themselves by breathing, passing air over their tongue and from their lungs to help dispel heat. Dogs with breathing problems or heart problems are more susceptible to heat stroke, as they cannot move air efficiently enough to dissipate heat. If the air outside is hot, moving already hot air in and out of the lungs does not allow for cooling. This is amplified dramatically inside an automobile, even with the windows cracked.
Short-faced (brachycephalic) breeds are more susceptible, (such as Pugs and English Bulldogs) as they have smaller chest cavities, excess throat tissue, narrow windpipes and often narrow nostrils all of which work together to make it harder for them to breathe and cool themselves.
Overweight dogs and dogs with thick fur (such as Chows) are more susceptible.
Dogs on medications that increase urination, such as prednisone or Lasix (furosemide), or those with diseases that cause increased urination, such as Cushing’s, diabetes mellitus, diabetes insipidus, and kidney compromise are often a bit dehydrated already which hastens heat stroke.
* Keep dogs in the house during the day (not a shed, garage, or other space that is not air conditioned). We have treated dozens of heat stroke patients that were kept in a garage with a fan and a bowl of water – the owners are always surprised that heat stroke still occurred. The air gets hot in a garage, and your dog cannot cool itself by breathing hot air in and out. If your dog must be outdoors, be sure their area is very well shaded during all hours of the day, they have cool ground (not concrete) to lie on, and they have access to plenty of fresh water. Check on your dog very frequently to be sure he / she is responsive and breathing without effort.
*Never leave a dog in a car during the day. Cracking windows is not enough. Have someone stay in the car with the dog, with the air conditioner running and water available.
*Prevent overexertion in any pet, especially those with short faces, heart problems, breathing problems, those with dense fur, those that are overweight, those with diseases that increase urination, and those on medications that increase urination.
*Stop strenuous activity (such as fetching a ball or jogging) before your dog is panting heavily. Do not force an exhausted dog to keep going. Wet them down thoroughly with water (it must penetrate the undercoat and soak the skin), get them inside an air conditioned space, provide water to drink, and take a rectal temperature using a flexible tipped, lubed, digital thermometer. Normal temperature is 99.5 to 102.5 degrees F. Get veterinary care without delay if your pet seems disoriented, off balance, mentally dull, or has a rectal temperature 103.5 degrees or higher.
*Do not use ice cold water or ice packs directly on the skin to cool your dog. Use luke warm water and thoroughly soak him or her, but only if you can do this immediately before getting to a veterinarian. Do not delay getting to the hospital.
*Prevent your dog from getting overweight. Obesity is a significant risk factor for heat stroke.
YOUR DOG THANKS YOU FOR BEING INFORMED!