Summer Dangers – Heat Stroke

As summer truly arrives, the hot and humid weather can create danger for our pets. Heat stroke is a serious, life threatening condition that affects both humans and animals. Immediate recognition and treatment of this condition in our pets can be lifesaving.

Heat stroke is a condition that occurs when the body is unable to cope with heat and, as a result, the body’s temperature becomes elevated. A normal body temperature for a dog is between 99F-102.5F. With heat stroke, temperatures can rise to as high as 106F-109F. In addition, such an elevation in body temperature can be fatal in as little as 20 minutes. Once the body temperature rises above normal, many compensatory mechanisms are engaged in effort to maintain a normal body temperature. Sweating is the human body’s major cooling mechanism. Dogs and cats do not sweat, and instead release heat at high temperatures primarily through panting. Panting alone will not cool a pet sufficiently in extremely warm temperatures. At warm temperatures dogs and cats depend on contact with cooler structures (such as lying down on a cool surface or in a shaded area) or simply being in contact with a cool air flow. When the body’s cooling mechanisms are overwhelmed, body temperature begins to rise and heat stroke can occur. As a result of the elevated body temperature many internal organs can be damaged, including the brain, lungs and heart. If the damage to these organs is severe enough, this condition can be fatal.

Heat stroke can occur due to two primary reasons: 1. a high level of activity in temperatures to which a pet is not acclimated (such as running or playing on the first few hot or humid days of the year) 2. the inability to dissipate heat because of a decrease in airflow, lack of shade or water, or increase in temperature or humidity (such as being confined to an enclosed area on a hot day).

Extra Caution Obese pets, brachycephalic pets (pets with short stubby noses such as Pugs, Boston terriers, and Persians), pets with airway disease (such as laryngeal paralysis, tracheal collapse), pets with a thick hair coat (Nordic breeds, Newfoundlands, St. Bernards), and pets with brain disease are predisposed to heat stroke, and, as a result, these pets can be affected at much lower temperatures.

We also see a spike in heat stroke cases during the first few truly warm spring days. No one has had a chance to acclimate to the warmer temperatures, and there is the chance that our dogs have developed age or disease related issues over the winter that did not affect them during previous seasons.

Signs of heat stroke include:

• increased breathing rate or effort
• weakness or lethargy
• collapse
• vomiting and diarrhea (which may contain blood)
• spontaneous bruising of the gums or skin
• walking with a wobbly gait
• decreased responsiveness
• blindness
• seizures

As the condition progresses, it can lead to kidney failure, severe bleeding into the intestines, damage to the heart with abnormal heart beat and low blood pressure, and bleeding into the lungs. Should the episode of heat stroke be severe enough, this condition can be fatal.

What should you do if you suspect your pet is suffering from heat stroke? First and foremost, treatment should be started as soon as possible to increase the dog’s chance of survival.

1. Immediately focus on cooling the pet. The pet should be removed from direct sunlight and sprayed down with cool, not cold, water. Cold water and ice packs should be avoided, as this can actually prevent heat loss from the skin. If you do not have access to water, move to a cool spot and head to a veterinary hospital. Don’t waste time searching for things to cool the pet.
2. The next immediate step is transporting the pet to a veterinary hospital where a thorough assessment can be performed and additional treatments can be provided. Upon arrival at the veterinary hospital, the staff will evaluate your pet’s vital parameters (heart rate, breathing rate, temperature) and evaluate your pet’s status. In effort to treat your pet, oxygen via a mask or an environmental oxygen cage and IV fluids are common first-line treatments, and the staff will continue to provide appropriate cooling treatments.
3. Depending on your pet’s heart rate or rhythm, an EKG may be needed to see if damage to the heart has occurred. Blood work will also be performed to screen for the presence of organ damage as well as to assess the risk for and severity of spontaneous bleeding (both internal bleeding and bruising of the skin). Depending on the severity of heat stroke and blood work findings, your pet may also need blood transfusions to stop internal and external bleeding. Blood transfusions will also provide your pet with red blood cells, which can be low if bleeding is severe.
4. The prognosis for heat stroke depends on the severity of illness and extent of organ damage. The faster the pet’s body temperature can be returned to normal, the greater the chance for survival. Most cases require a few days of hospitalization, but mild cases with no bleeding or organ damage may respond well with 24 hours of care.

Because of the critical nature of this condition, 24-hour care is recommended for these pets. Such dedicated and continuous care can be provided by your local emergency veterinary hospital where doctors and nursing staff are present 24-hours a day to monitor and treat your pet. The Veterinary Medical Center of CNY (VMC) is staffed and open 24-hours a day, 365 days a year to treat your pet. In addition, the VMC has two board certified Critical Care specialists on staff who have been extensively trained to treat this condition. The VMC is the only 24-hour veterinary hospital in the Syracuse area, and is the only private veterinary hospital in Central New York to have board certified Critical Care specialists on staff. Our criticalists have developed our protocols and trained our entire Emergency Service to respond quickly, appropriately, and professionally to these situations. At the VMC last year, more than 75% of dogs with severe heat stroke were treated successfully—even though many were in extremely critical condition at presentation—thanks to the intensive, compassionate care provided by the doctors and staff at the VMC.

In order to prevent your pet from suffering from heat stroke, please follow these guidelines:

• Avoid excessive activity or rigorous exercise in hot and humid weather – restrict summer activity to early morning and late evening when temperatures are cooler
• Slowly acclimate your pet to the increased Summer temperatures
• Be sure your pet has access to shade and cool water
• NEVER leave your dog unattended in your car on a warm day
• Use additional caution with predisposed breeds and pets with predisposing conditions (mentioned above)

As always, be prepared – know where your closest emergency veterinary facility is located, just in case your pet needs care!

This blog post was written by the VMC’s Medical Director, Maureen Luschini, VMD, DACVECC