Heatstroke is a life-threatening emergency. Seek veterinary attention immediately.
Heatstroke involves potentially life-threatening elevations in body temperature (hyperthermia). Heatstroke is an emergency. It can lead to rapid multi-organ failure and death.
The focus is often on dogs but other companion animals, and farm animals, are also vulnerable to heatstroke.
Signs of heatstroke
Signs of heatstroke vary depending on the species but may include lethargy (low energy), fast breathing, shaking and collapse.
Risk factors for heatstroke
Heatstroke occurs when an animal is unable to maintain their normal body temperature. Some risk factors include:
- Species – small animals (e.g., rabbits, guinea pigs, ferrets, birds, rats, mice) are highly susceptible to heatstroke because they have a small surface area to volume ratio which means they cannot lose heat as fast as larger animals.
- Age – Very young animals have a limited ability to regulate their body temperature, and very old animals are more likely to have health conditions that limit their capacity for cooling.
- Environment – Heatstroke is a greater risk when there is insufficient air flow, lack of shade and water, and in warm/hot, humid weather but heatstroke can develop even in cooler weather if other risk factors are present.
- Exercise – Exercise can result in heatstroke if heat generation exceeds heat loss (e.g., excessive exercise, exercise in hot weather, lack of shade).
- Transport – Transport involves multiple risk factors for heatstroke including stress, insufficient air flow, lack of shade and water, and a warm/hot environment.
- Climate change – The risk of heatstroke is increasing with climate change as temperatures rise, and heatwaves become more frequent and prolonged.
Minimising the risk of heatstroke
Minimising the risk of heatstroke involves addressing the risk factors, and ensuring all animals have the means to keep cool (e.g., free access to water, cool areas to retreat to).
- Cats – cats need to be provided with access to cool areas and if it is too hot outside may need to be confined indoors. Stroking with a damp towel may help them cool down.
- Rabbits, guinea pigs, rats, mice, ferrets – These animals are often confined in cages and hutches and are unable to move to cooler places to escape the heat. In hot weather, they need to be moved into a cool, shaded, and well-ventilated area indoors (e.g., laundry). For more information on heat stress in rabbits, see this article.
- Birds – In hot weather, birds will need extra shade (e.g., 90% shade cloth), fans, ice -blocks in their nesting boxes, and frozen fruit and vegetables.
- Fish – The body temperature of fish is dictated by water temperature. Monitoring water temperature is vital. If water temperature in their tank or pond rises on a hot day, they can become stressed, develop diseases, be deprived of dissolved oxygen, and die. Depending on the situation, shade, air conditioning and frozen water bottles may help. Different types of fish have different water temperature needs. Seek advice from an aquarist.
- Amphibians and reptiles – These animals can suffer from potentially fatal heatstroke. The body temperature of amphibians and reptiles is dictated by environmental temperature. It is essential to provide a thermal gradient (range of temperatures) in their environment, so they have the choice to cool down if they need to. Different species use different strategies to keep cool (e.g., seeking cooler areas, using water, burrowing under cool earth) and species-specific means of cooling must be made available.
If you suspect your animal is suffering from heatstroke, seek veterinary attention immediately.
