By Elyse Politica,
DVM, PVESC
What is heatstroke?
Heatstroke occurs when an animal is producing too much heat and cannot get rid of it quickly enough. This can be a life-threatening emergency because high, prolonged elevations in body temperature can cause organ dysfunction and even death.
Heatstroke is a common emergency, particularly in the summer months. Animals can get heatstroke secondary to strenuous exercise during warm weather, or from simply being in a very hot environment for long periods of time (i.e. locked in a hot car or trapped on a porch in direct sunlight). Animals that are at a higher risk of having heatstroke are those with shorter noses (aka brachycephalic breeds), those that are overweight, older in age, or have other comorbidities such as endocrine disorders.
Signs that an animal is experiencing heatstroke can include panting, weakness, collapse, vomiting, diarrhea, and even seizures or a coma. If these signs are noticed, particularly after an animal has been in a hot or humid environment, the pet should be immediately evaluated by a veterinarian.
Diagnosis:
A diagnosis of heatstroke is often made based on the patient’s history and initial exam/diagnostics.
When bringing your pet into an emergency hospital for concerns of heatstroke, a veterinary nurse will triage your pet to first assess how stable he is. The triage process helps identify pets who should be evaluated more emergently than others. This may involve taking your pet’s vitals and finding out his recent/pertinent history. The doctor will then perform a thorough physical exam. Some of the main factors that the doctor will be evaluating during his exam will include heart rate, body temperature, pulses, mucous membrane color, respiratory rate/effort, and mentation. With heatstroke, physical exam findings may show a high heart rate (tachycardia), weak pulses (a sign of poor blood circulation), pale mucous membranes, and/or altered mentation. Altered mentation may range from being quieter than usual, not responsive to normal stimulation, or comatose.
Depending on the severity of the pet’s condition, different diagnostics may be recommended. Some initial tests can include bloodwork, blood pressure, assessing blood clotting times, performing imaging, or doing an electrocardiogram. These diagnostics can help assess organ function, metabolic status, screen for electrolyte derangements, and evaluate cardiovascular status (how well the heart is pumping blood and delivering oxygen throughout the body). Additional tests may be indicated based on the status of the patient.
Prognosis:
The outcome of a pet often depends on how high his body temperature became and how long it stayed elevated for. Animals that present quickly to a veterinary hospital and who have not had high temperature elevations for a prolonged time tend to have a better prognosis.
When at a veterinary hospital, your veterinary care team will create a tailored treatment plan focusing on lowering the animal’s body temperature, correcting any electrolyte or blood sugar abnormalities, and administering intravenous fluids and other medications as needed.
Heatstroke can be a life-threatening condition, and unfortunately some animals are not able to make it out of the hospital. For animals that do survive, there can be permanent damage to organs which requires ongoing monitoring/treatment.
Prevention:
• Keep your pet out of extreme heat.
• Limit outdoor exercise during very warm days.
• Do not leave animals unattended in a car when the weather is warm.
• When animals are outside on hot days, always have water and a region of shade available to them.
• Avoid walking your pet during the afternoon on hot days when heat and humidity are at their peak.