Heatstroke in Cats

What Is Heatstroke in Cats?

Heatstroke in cats can occur in several possible scenarios. Most commonly, it happens to cats who are unable to escape extreme heat, such as those left in a hot car, or outdoor cats without adequate shade and access to water. Heatstroke may also occur in cats that exercise strenuously on hot days or expend a lot of energy when they have long episodes of seizures or tremors, or it may occur in flat-faced cats struggling to breathe on warm or humid days.

During a heatstroke, when a cat’s body temperature surpasses 104 F, there is a significant release of inflammation throughout their body. This inflammation sets off a cascade of reactions that affects every major system of the body, causing the breakdown of essential proteins and enzymes. This puts the cat at risk of organ failure and potentially death.

If your cat is experiencing heatstroke, contact a veterinarian immediately.

What Is the Difference Between Heatstroke and Heat Exhaustion?

Heat exhaustion is an early stage of heatstroke, when the cat’s temperature is approximately 103–104 F. Recognizing the following signs and acting quickly can prevent heatstroke and tissue damage.

During heat exhaustion, a cat may seek a cooler area, such as a tile floor or a shady spot. They may pant, start to drool, develop sweaty paws, drink more, and start to groom themselves to cool off.

If you notice any of these signs, immediately do the following

• Move your cat to a cool, air-conditioned area.

• Place a slightly cool, damp towel on your cat’s back. If your cat allows, place a damp towel under their belly. Rubbing cool water on the paw pads and ears will also help with cooling.

• Offer your kitty cool water to drink; some cats may like ice cubes.

• If your cat’s symptoms are not relieved within 15 minutes or your cat’s condition appears to worsen, seek immediate veterinary attention.

Heatstroke is the more severe stage, where the cat’s body temperature rises over 104 F. At this point, tissue damage starts to occur, and the cat develops more severe symptoms.

It is important to start brief cooling at home, such as applying cool damp towels and water to the ears and paws, but head directly to a veterinarian for emergency care.

Symptoms of Heatstroke in Cats

To recognize heatstroke in cats, watch for the following symptoms:

• Rectal temperature greater than 104 F

• Disorientation

• Reddened gums

• Vomiting and/or diarrhea, which may contain blood

• Pinpoint spots of bleeding on the skin, whites of the eyes, gums, inside of the ears, and belly

• Labored breathing, panting, and wheezing

• Seizures

• Collapse, inability to walk or stand up

Causes of Heatstroke in Cats

Cats most at risk for heatstroke include:

• Outdoor cats, especially on very hot days, very humid days, or when there is little shade or water available

• Indoor cats let outside into hot temperatures when they are not used to the heat

• Indoor cats when there is no power or air conditioning in the home

• Brachycephalic (flat-faced) cats, on any warm day

• Obese cats

• Senior cats

• Kittens 4 months of age or younger

• Cats with underlying health issues such as kidney disease, diabetes mellitus, or mobility issues that hinder their access to water

• Cats with heart, respiratory, or neurological conditions (such as seizures)

• Cats inadvertently trapped in a running clothes dryer

• Cats unintentionally confined in a car (even on mild days, the interior of a car can quickly become dangerously hot)

How Veterinarians Diagnose Heatstroke in Cats

The diagnosis of heatstroke in cats primarily relies on both the cat’s history and a physical examination. A cat with a history of exposure to a high-temperature environment, prolonged seizures or tremors, a flat-faced cat struggling to breathe on a warm day, and having a body temperature above 104 F, with any of the signs of heatstroke, is a strong indicator.

The veterinary team will immediately take blood samples as well as start pulse oximetry to determine the oxygen saturation of the blood and start an ECG to monitor the heart. In most cases, supplementary oxygen will be needed, at least initially. Lab tests are used to check for any major and minor infection in the blood throughout the cat’s stay, including kidney and liver injury.

The team will pay close attention to the cat’s body temperature, because once cooling efforts start, they do not want the body temperature to drop too low.

Treatment of Heatstroke in Cats

The first step in treating a cat with heatstroke is to bring their body temperature back to a more normal range. This is primarily achieved through intravenous (IV) fluid therapy. Your vet will pay close attention to how alert the cat is upon arrival for treatment and whether the cat becomes more or less alert as the treatment progresses. Cooling of the ears, feet, and belly with tepid water may also continue in the hospital, depending on the cat’s temperature when they arrive.

Heatstroke patients often experience low blood sugar. The addition of glucose to their IV fluids over several days will prevent seizures or other side effects of low blood sugar. Throughout the hospital stay, lab tests will be used to screen for kidney and liver injury.

Heatstroke can lead to a breakdown of the lining of the blood vessels, causing a greater risk of bleeding. If this occurs, the cat may benefit from one or more transfusions of fresh frozen plasma from a healthy donor cat to replace clotting factors.

Cats that become comatose may have cerebral edema, or brain swelling. This may be treated with mannitol, a diuretic IV medication. Cats with heatstroke are also more susceptible to sepsis (severe infection throughout the entire body), so antibiotics are often used.

Cats that are having difficulty breathing may receive supplementary oxygen by remaining in an oxygen cage. Some cats that are in severe respiratory distress may need to be intubated and ventilated to help them breathe.

Kidney failure from heatstroke is possible. If this is the case, fluid therapy is essential but must be carefully monitored. In either of these cases, the veterinarian may recommend referral to a facility where a ventilator or kidney dialysis is available.

Recovery and Management of Heatstroke in Cats

In mild to moderate cases of heatstroke, cats often make a full recovery by the time they are discharged from the hospital. Medications to take home may include antibiotics such as Clavamox® and gastrointestinal protectants.

Your veterinarian may want to see your cat back in five to 10 days to perform a recheck examination and lab tests to assess organ function, and sooner if your cat experiences vomiting, diarrhea, or disorientation. Your cat will need ample rest once they are home but should recover soon.

In very severe cases of heatstroke, the prognosis is guarded to poor. It is reasonable to ask your veterinarian about the expected long-term care for your cat, as some pets with severe heatstroke may require long-term treatment for kidney failure, heart disease, or neurological problems.

Keep in mind that cats that have had heatstroke are more sensitive to a recurrence of heatstroke in the future. They should be kept indoors and protected from heat.

Prevention of Heatstroke in Cats

To prevent heatstroke in cats, take the following precautions:

• On hot days, keep cats indoors where there is air conditioning.

• Do not let cats out on a catio or into the yard on hot or warm, humid days.

• Before using your clothes dryer, check for the presence of a cat to prevent accidental entrapment.

• Place a bag or purse on or next to the cat carrier to ensure you don’t accidentally leave your cat in the car.

• Install a Wi-Fi thermostat in your home to receive alerts if the power goes out, so you can get your cat to a cooler place if you are not home.

• Make sure outdoor cats have plenty of shade and access to water.

• Give cats with seizures their medications regularly, as missed doses can trigger episodes.