During a 2006 heat wave that struck throughout the West, a dog in Washington state on a run with its owner became so overheated and dehydrated due to heat stroke that the dog's kidneys stopped functioning.
"Heat stroke can be life-threatening in dogs. Most dogs don't know when to stop and rest," explains Karl Jandrey, a veterinarian in the Emergency and Critical Care Services of the Veterinary Medical Teaching Hospital at the UC Davis School of Veterinary Medicine.
A normal internal temperature for most dogs, says Jandrey, is about 100-102.5 degrees Fahrenheit. Some working dogs adapt to higher temperatures during activity, but a dog with heat stroke may have a temperature in excess of 107 degrees. "Heat-induced illness just denatures everything," Jandrey explains. Sustained heat exposure can lead to seizures, irregular heart beats, diarrhea, and vomiting. Blood may fail to clot, and loss of kidney or liver function can occur.
To compound the difficulty, symptoms of heat stress in dogs may not show until the animal is near collapse. Fortunately, the Washington dog owner arranged for the animal to be flown to the UC Davis Veterinary Medical Teaching Hospital. Emergency specialists provided life-saving measures in the Intensive Care Unit while the Hemodialysis Service provided treatments to temporarily take over the function of the dog’s failing kidneys.
Dogs do not have sweat glands like people do. They cannot cool themselves by sweating through the skin. Instead, they regulate their body temperature through their breathing (ventilation). It is normal for a dog to pant heavily in warm weather. The brachycephalic breeds, those which appear to have "pushed in" faces such as pugs, boxers, and bulldogs may be more prone to overheating. This is due to the unusual anatomy of their shortened facial features and airways.
Since the consequences can be so dire, Jandrey recommends the following preventive tips:
· Provide plenty of fresh water
· Gradually increase activity levels and give the dog lots of rest breaks during exercise. UC Davis veterinarians begin to see heat stroke cases as early as April, even though temperatures are mild, because dogs have not had time to acclimate to warmer days and strenuous exercise.
· Soak your pet to the skin with a hose or bath of tepid water. "Misting isn't going to cut it," Jandrey says. "Water shouldn't be so cold that it constricts surface blood vessels and actually blocks the cooling process. No ice."
· Place the animal in front of a fan to speed up the cooling process.
Jandrey cautions, "Fixing the temperature is not necessarily the end of the story—problems can still be moderate to severe." Therefore, he advises a visit to the veterinarian for a health assessment after an episode of overheating.
In extreme cases, treatments at UC Davis may include intravenous fluids and blood transfusions, muscle relaxants and sedatives to reduce seizures, and other intensive care measures, such as oxygen therapy to support failing lung function.
UC Davis School of Veterinary Medicine has one of the only animal programs on the West Coast that provides emergency kidney dialysis services. The school runs hemodialysis services in two locations, in Davis at the William R. Pritchard Veterinary Medical Teaching Hospital and in San Diego at the UC Veterinary Medical Center - San Diego. Another instrument at the school's teaching hospital that is not widely available elsewhere is a mechanical ventilator that assists the animal with breathing. The Small Animal ICU provides 24-hour individual patient care every day of the year and is the leading veterinary facility for mechanical ventilation for both dogs and cats.
The weather has cooled considerably. Jandrey's patients are back with their owners. Summer is not over, however. It pays to prepare yourself—and your dog—for the next hot spell.
*This tip from Dr. Karl Jandrey of the UC Davis Veterinary Medical Teaching Hospital provides general information about animal health. If you have specific questions about the health of your pet, please consult your veterinarian. You may make an appointment at the Small Animal Clinic by contacting the Veterinary Medical Teaching Hospital, (530) 752-1393.
Lynn Narlesky, Dean's Office, (530) 752-5257,