Hyperthermia is common in Australian summers
Heat stroke or hyperthermia is commonly seen during the summer months in Australia in patients (dogs more often than cats) that have been exercising in hot and humid weather, or confined in a closed space (such as a car). Animals without access to shade or water will have an increased risk of developing heat stroke. Some breeds of dog have an increased risk of developing heat stroke as their ability to pant is inhibited by their facial anatomy (e.g. bulldogs, pugs). You should also know that heat stroke can also be seen in patients who have seizures or severe difficulty breathing, irrespective of the environmental temperature. When the body reaches temperatures above 41oC, the proteins can cook, killing cells and leading to organ damage and death.
Panting +/- difficulty breathing or increased effort/noise when breathing
Depression, lethargy or even coma
Lack of co-ordination
Bright red or blue tinged gum colour
Dark coloured urine
Heat stroke is a life threatening condition, seek veterinary attention immediately.
Emergency treatment before transport to a veterinarian
- Saturate animal with cool tap water. Spend at least 5 minutes doing this before transporting your pet to the vet as this therapy can be life saving. Do not use ice as the application of very cold things to the skin causes the blood vessels in the skin to constrict which impairs heat loss.
- Transport pet with windows open or air-conditioning on and attempt to keep the coat wet during transit
- Once your pet cools down, it may stop panting and begin to shiver. It is very important at this stage to dry your pet and keep it warm
- What to expect at the vet:
- Oxygen therapy or airway intubation if your pet is having difficulty breathing
- Intravenous fluid administration is often given to assist with cooling and for the treatment of shock
- Intravenous medications may be required to control seizures and protect gastrointestinal tract
- A cool water enema can be used in severe cases to assist with cooling
- Blood or plasma transfusions if severe and clotting problems develop
- Blood testing is often required to assess severity of condition, and monitor response to treatment
Heat stroke is a life threatening condition that can cause damage to and even failure of multiple organs, including the heart, lungs, kidneys, clotting system, gastrointestinal tract and brain.
Treatment of this disease can be complex and challenging, and may require extended hospitalization with significant medical costs.
With appropriate and timely medical therapy, many patients recover. Unfortunately, if this treatment is not instigated, reports have shown that over half of animals with heat stress can die.
Image 1: Brick red gums of a dog with heat stroke
Image 2: Pale gums of a dog with heat stroke that is in hypovolaemic shock