It always amazes me when, every year as the temperatures rise, there are still reports of animals being left alone inside hot vehicles, despite the fact that the dangers of doing so are well-known. Animals that exercise too vigorously in the heat or cannot seek relief from it are also at risk for illness and injury. Not too long ago, I had a concerning experience like this with my own dog when I took him out for a little fun in the dog park. That’s why, as the dog days of summer arrive, I thought it might be helpful to review some simple facts about how the heat can affect our pets.
Balmy Weather? Still Deadly
It’s important to realize that dogs and cats can develop heat-related injury quickly when they stay inside a parked car or other vehicle. This can happen even when the windows are partially lowered, the vehicle is in the shade, or the outside temperatures seem relatively moderate. Many people do not realize just how quickly the interior temperature of a car can increase to deadly levels, even with some airflow provided by cracked windows. For example, on a 90-degree day, the temperature inside a closed car can climb to 109 degrees within just 10 minutes. In less than 50 minutes, temperatures in that same car can rise to above 130 degrees. On even a comparatively balmy 70-degree day, temperatures inside a vehicle can reach triple digits within 30 minutes (see table).
Heat toxicity can also occur in dogs that exercise too vigorously during periods of high heat, especially if the humidity is also elevated. Even dogs that are in good athletic shape and used to regular exercise can develop heat injury when out and about in extreme conditions. Heat toxicity, or heat injury, can run the gamut from heat exhaustion (which occurs in the early stages of a heat-related event) to heat stroke, which is a full-blown emergency that requires immediate veterinary intervention.
What Happens to a Heat-Stressed Pet?
During heat stress, the animal’s internal body temperature can increase rapidly, and fatal organ failure can follow. Since dogs and cats do not sweat (except on footpads and the nose) the way humans do, they cannot use this as a method to lower body temperature. Instead, dogs and cats try to regulate their body temperature by panting to help body heat dissipate. This response, however, is limited and easily overwhelmed under extreme conditions.
Signs of Heat Stress
Initial signs of heat toxicity include:
Excessive salivation (which is often thick and ropy)
Bright red membranes of the mouth, tongue, eyes, and sometimes skin in light-pigmented dogs
Vomiting and diarrhea can also occur due to damage to the gastrointestinal tract
Multiple organs can fail if the excessive heat retention is not relieved soon enough. These organs include the gastrointestinal tract, kidneys, liver, heart, muscles, brain, and bone marrow. Heat retention causes the blood vessels to dilate, and a form of shock develops as the condition advances.
If the animal is in a state of collapse when found, it is imperative to get him to your local veterinarian or an emergency clinic immediately. Quickly cooling the animal for the trip with cool water from a garden hose may be helpful but do not immerse your dog in cold or ice water as this could lead to shock. If shock does develop, intravenous fluids and other medications may be needed for a few days upon arrival at the hospital.
Source: Dr. Dennis Chew