The Peril of Hot, Closed Cars Temperatures

Summer offers the promise of shared fun – outdoor games, longer walks, romps on the beach—but high temperatures can also put your dog at risk for threats to his healt.  The most serious is heatstroke, says Gretchen Schoeffler, DVM, Section Chief of Emergency and Critical Care at Cornell’s Hospital for Companion Animals.

“Heatstroke is usually due to excessive or even moderate exercise in a poorly conditioned dog, or it can be due to an excessively hot environment – a closed car is classic.”

The Critical Elements.  A dog’s chances of survival: “It depends on how severely he is affected and the length of time to treatment,” Schoeffler says.  Time and temperature are the critical elements when a dog is in a closed car.  When it’s 75 degrees outside, it takes only 10 minutes for the temperature inside to reach 94 degrees.  Ten minutes later, the interior temperature can reach 104, according to a study by Stanford University and meteorologist Jan Null, a lecturer in extreme weather at San Francisco State.

The study shows that vehicles can very rapidly reach life-threatening temperatures even on mild days,” Null says.  While the atmosphere and car windows are relatively transparent to the sun’s shortwave radiation and warmed little, the energy can heat objects, the study found, adding that a dark dashboard or seat can reach 180 to over 200 degrees.  (The study, published in the journal Pediatrics, concerned the death of children left in hot cars.”

Puppies, geriatric and dark-coated dogs are especially vulnerable to heatstroke.  “Some breeds are also predisposed—those who cannot dissipate heat as efficiently, for example, brachycephalic breeds,” Dr. Schoeffler says.  These short-nosed dogs include Bulldogs, Pugs, Pekingese and Boston Terriers.

“Overweight or poorly conditioned dogs are also predisposed, as are dogs with diseases that impair their ability to dissipate heat, such as heartdisease, laryngeal paralysis and tracheal collapse,” she says.

Dogs are at a disadvantage in warm weather.  They cool themselves by panting and, to a lesser degree, by sweating through their footpads.  Their normal temperature ranges between 101 and 102.2 degrees Fahrenheit.  If their temperature reaches 106 degrees and higher, however, multiple organ failure can develop, resulting in deah.

If left untreated, the early signs of overheating such as heavy panting, rapid heart rate, drooling and lethargy may progress to full blown heatstroke.  Some of the classic signs are obvious and constitute a medical emergency:

>> Weakness

>> Vomiting

>> Disorientation and dizziness

>> Diarrhea that may contain red blood

>> Tremors

In addition, a dog may have bright red gums and eyes, and exhibit spontaneous bruising on the inside thighs, gums, ears and abdomen, Dr. Schoeffler says.  In some cases a dog will collapse and go into a coma.  If you’re worried your dog is overheated, you should douse him with tepid, room-temperature water—not cold—and seek immediate veterinary care.

Prompt, aggressive treatment at the clinic can include lowering the core body temperature, giving fluids to correct inadequate circulating or blood volune, and managing secondary complications.

Guarded Prognosis.  The prognosis for heatstroke varies and depends on the duration of exposure, rapidity of treatment and maximal core body temperature achieved, as well as the presence of pre-existing conditions and development of complications.

The most important advice for owners: “Pay attention to your dog.”  Dr. Schoeffler says.  “When he sits or lies down to take a break, do not coax or encourage him to keep going.  Always have water available—port it when hiking or away from home.  And never leave your dog unattended in the car or other such space.”