There are three types of hyperthermia, often used interchangeably, but they vary in severity:
Heat Stress: Characterized by increased thirst and panting. The dog remains mentally aware and can move about. For more details, visit our "Heat Stress in Dogs" blog.
Heat Exhaustion: A more severe form of heat stress with significant thirst, general weakness, and heavy panting. Dogs are mentally aware but may be too weak to react, move around, or may collapse.
Heat Stroke: The most severe form of hyperthermia. It occurs when a dog's temperature reaches 41.1°C (106°F) or higher, leading to neurological and organ dysfunction or failure. At 43°C (109.4°F) or higher, cellular proteins begin to melt, causing widespread cellular damage. Prolonged exposure to such high temperatures increases the risk of severe organ damage and death.
What are the signs and symptoms of heat stroke in dogs?
Heat stroke in dogs can progress rapidly and become life-threatening. Early signs to look out for include:- High body temperature
- Restlessness or agitation
- Excessive panting or difficulty breathing
- Drooling, often with very thick saliva
- Change in gum color (dark red, pale, purple, or blue)
- Vomiting or diarrhea (possibly with blood)
- Increased heart rate
- Lethargy or collapse
- Dizziness or difficulty walking in a straight line
- Muscle tremors
- Seizures
- Unconsciousness
Why does heat stroke occur? Main Predisposing Factors
Heat stroke in dogs can occur due to various factors, primarily related to environmental conditions, but some dogs are at increased risk due to their breed or pre-existing medical conditions.
Environmental Factors
Heat stroke can be triggered by:
- High temperatures
- High humidity
- Lack of adequate airflow or ventilation
- No access to or inadequate shade
- No access to or inadequate drinking water
- Excessive exercise
- Lack of acclimatization to hot weather (dogs may take up to 60 days to adjust to significant temperature changes)
- Being left in closed homes/garages without air conditioning
- Being left in cars, where temperatures can rise quickly even on mild days or with windows slightly open
Breed and Pre-existing Medical Factors
Certain pets are more susceptible to heat stroke, including:
- Small animals like birds, guinea pigs, rats, mice, rabbits, and ferrets, which are often confined to cages and cannot move to cooler places. These animals should be kept in cool, shaded, well-ventilated areas with plenty of drinking water. Draping cages with wet towels and providing ice packs or frozen water bottles can help regulate their body temperature.
- Pets at extreme ages (young and old)
- Pets with thick or long coats that retain heat
- Overweight and obese dogs
- Large breed dogs
- Extremely active, working, or hunting dogs, such as shepherds and retrievers
- Brachycephalic breeds (short-nosed and flat-faced animals) like pugs, English bulldogs, French bulldogs, Pekingese, and Persian and Himalayan cats. These breeds have smaller and narrower nostrils, a long soft palate, and smaller airways, making it difficult for them to cool themselves efficiently. They are 146% more likely to suffer from heat stroke than other breeds.
- Pets with respiratory diseases or breathing problems, such as laryngeal paralysis or collapsing trachea
- Pets with heart or cardiovascular disease
- Pets with neurological diseases
- Dehydrated pets
If you suspect your pet is suffering from HeatStroke seek professional help immediately!