Heatstroke in Cats

Feline heatstroke is a rare, potentially fatal condition that occurs when body heat cannot dissipate effectively. Prognosis varies depending on the temperature and duration of exposure. Any cat showing collapse, panting, or stupor needs to be examined by a veterinarian immediately.

As heatstroke is rare in cats, most information on feline heatstroke is extrapolated from what is known about heatstroke in dogs which is much more common.

Cats instinctively avoid conditions where overheating is likely, so most cases of heatstroke result from being trapped in a hot environment such as the interior of a car or a clothes dryer.

Risk factors like being a flat faced breed, being dark coated, heart disease, or obesity can make cats more susceptible to heatstroke.

Severe symptoms are related to the degree of bodily damage. A normal feline temperature ranges between 100 F (37.8 C) and 103.1 F (39.5 C). Damage to the nervous system occurs at temperatures of 105.8 F (41 C) or greater. Cell death occurs at temperatures of 106.7 F (41.5 C) or greater.

Prolonged exposure to elevated temperatures can cause irreversible brain damage and widespread tissue destruction.

Heatstroke can be caused by two different scenarios. Environmental heatstroke is caused by prolonged exposure to hot, humid environments. Most cases of feline heatstroke are environmental and are caused by being left in a hot car or accidental entrapment in a working drier. Exertional heatstroke is caused by excessive exercise or prolonged seizure activity.

Symptoms are progressive and vary depending on the temperature and duration of exposure. Heat stress and heat exhaustion are precursors to heatstroke.

Diagnosis of heatstroke is made based on clinical exam and history. Blood work, blood pressure, and ECG are used to support the diagnoses of heatstroke and further determine the overall health status of the cat.

Immediate cooling is the most important form of first aid. Room temperature water can be used to cause evaporative heat loss and cool the pet on the way to the vet.

Supportive care to manage secondary complications include:

• IV fluid therapy
• Oxygen
• IV dextrose
• Medications to combat brain swelling
• Fresh frozen plasma
• Antibiotics
• GI protectants

Heat stroke continues until cooling measures are taken. Complications may develop over 12-24 hours and require several days of hospitalization. In severe cases pets may die from secondary complications.

Mortality rates for cats are not known, but depend on severity of signs at presentation and response to treatment.

Keeping pets in a climate controlled environment, controlling seizures, not exercising in hot environments, and maintaining a healthy weight all help to prevent heatstroke. Heatstroke can also be prevented by avoiding leaving pets unsupervised in cars. Cats being unknowingly trapped in clothes dryers can be prevented by ensuring the dryer is cat free prior to starting.

Heat stroke is not contagious.

Heatstroke is uncommon.

Treatment consists of:

• Cooling with room temperature water and fans
• IV fluids therapy
• Oxygen
• IV dextrose
• Medications to combat brain swelling
• Fresh frozen plasma
• Antibiotics
• GI protectants