Heat Stress in Pets and Livestock

Guidelines for Pet Owners to Manage Heat Stress

Dogs and Cats

• Never leave your pets in a parked car. On a warm day, temperatures inside a vehicle can rise rapidly to dangerous levels. On an 85 degree day, for example, the temperature inside a car with the windows opened slightly can reach 102 degrees within ten minutes. After 30 minutes, the temperature will reach 120 degrees.
• Shade and water are a must. Anytime your pet is outside, make sure he or she has protection from heat and sun (a doghouse does not provide relief from heat) and plenty of fresh, cool water. Heat stroke can be fatal for pets as well as people.
• Limit exercise on hot days. Take care when exercising your pet. Adjust intensity and duration of exercise in accordance with the temperature. On very hot days, limit exercise to early morning or evening hours, and be especially careful with pets with white-colored ears that are more susceptible to skin cancer, and short-nosed pets. Asphalt gets very hot and can burn your pet's paws.

Recognize the signs of heatstroke. In case of an emergency, it's important to be able to identify the symptoms of heat stress caused by exposure to extreme temperatures. When in doubt, contact your veterinarian immediately. Some signs of heatstroke are: heavy panting, glazed eyes, a rapid heartbeat, restlessness, excessive thirst, lethargy, fever, dizziness, lack of coordination, profuse salivation, vomiting, a deep red or purple tongue, and unconsciousness. If the animal shows symptoms of heatstroke, take steps immediately to gradually lower her body temperature and contact your veterinarian as soon as possible. Follow these tips, and it could save her life:

• Move the animal into the shade or an air-conditioned area.
• Apply ice packs or cold towels to her head, neck and chest or run cool (not cold) water over her.
• Let her drink small amounts of cool water or lick ice cubes.
• Take her directly to a veterinarian.

Rabbits

• Every rabbit owner should know that the safest place for a rabbit to live is indoors. Rabbits should never be kept outdoors! Domestic rabbits are different from their wild relatives—they do not tolerate extreme temperatures well, especially in the hot summer months Intense heat and humidity are hard on rabbits - in fact, the heat is worse on most rabbits than the bitter cold of winter.
• Rabbits should never be kept in the direct sun- a sheltered or shady place is necessary. Rabbits can tolerate up to about 80 degrees if it isn't a 'humid' heat, but in temperatures above that, they begin to really suffer in those thick coats of fur.
• Rabbits cannot sweat, nor do they pant like other animals (unless they are under heat stress-a danger sign) - their ears are the most efficient part of their bodies that allow heat to escape.
• Feed and water - rabbits eat a lot less during hot, humid weather. Rabbit pellets can spoil quickly in hot, damp weather so be careful to always empty out the food dishes before you feed the next meal - a build up of uneaten pellets can act like a sponge and soak up surrounding moisture from the air - and this is not good for the rabbit to eat!

Rodents

• Room temperatures (75 ºF) are warm enough for most pet rodents. Wild rodents are very adaptable in various temperature ranges, but unlike captive rodents they can move in and out of desired areas.

Horses

• Provide ample fresh, clean water. Check daily that buckets or troughs are not contaminated with bird droppings, insect larvae, chaff, or algae growth. Try to keep the water cool. Horses may not want to drink warm water. Ponies and foals may have trouble reaching to the bottom of a shallowly filled trough. Make sure everyone in your paddocks can reach the water.
• Sponge or hose down the large blood vessels along the inside of the legs, belly, and neck. Don’t spray the horse’s face or get water in its ears—sponge them down gently.
• If you must work your horses hard, try to schedule your session for early morning or late evening when it is cooler.
• After riding or driving in hot weather, cool your horse down slowly. Loosen girths or belly bands immediately after a work out. Offer sips of cool—not cold—water and walk the horse slowly. Muscles are more apt to stiffen if the horse is allowed to stand, and moving muscles dissipate heat better than stationary ones.
• Make sure there is a place for your horse to avoid the sun, either a building or a shade tree.
• Clip horses with heavy coats. Be careful not to clip too close however, since exposed skin can sunburn.
• Apply zinc oxide cream to horses with pink noses to prevent and treat sunburn.
• During very hot weather, consider keeping your horses stabled during the day, and let them out at night.
• Mid to late summer weather often means that grass growth slows down and pasture quality declines. Make sure your horse is getting enough fodder and consider supplementing with hay if necessary. Horses need energy to stay warm and cool. Adjust your feed mixture if your horse begins to lose condition in hot weather.
• If your barn becomes hot and stuffy, consider setting up a fan. Make sure the horse cannot reach the cord or fan itself, it can’t be tipped, and that it is plugged into a ground fault interrupt electrical receptacle if there is any chance of electrical wiring coming into contact with moisture, such as a spilled water bucket or a curious horse’s mouth.
• If hot weather brings clouds of biting insects that keep your horse pacing and stomping, try using fly sprays, masks, and sheets. Water-based fly sprays may be less harsh on the coat hairs, as oil-based ones can cause bleaching.
• Take care of yourself. If you get overheated and tired, you may not be able to take care of your horse effectively. And you could miss warnings that your horse itself is showing signs of heat stress.
• Heat stroke can happen to horses whether they are working hard, standing in stuffy stables, or traveling in trailers. Call a vet and take immediate action if your horse exhibits any symptoms of heat stress.

What to Do Until the Vet Arrives

• Use shade, cool water, breezes, or fans as best you can. Stand your horse in a pond or stream. Sponge or spray the large blood vessels along the inside of the legs and belly. Offer sips of water.

General Guideines for Livestock Owners to Manage Heat Stress

• Keep an eye on the animals and check them often.
• Providing plenty of clean cool drinking water and freshen it frequently. Water consumption may increase by as much as 50%.
• Provide shade for animals with temporary structures if needed. If kept indoors, be sure there is good ventilation. Use fans if necessary to keep the air circulating and animals more comfortable.
• Don't overgraze in pastures. Typically, the taller the grass, the cooler the pasture will be.
• Consider feeding more at night rather than in the morning to shift heat fermentation to a cooler part of the day. The heat of digestion can place additional stress on the animal. Consider temporarily reducing amount of feed.
• Work livestock early in the morning to decrease the risk of heat stress. A danger sign in goats, sheep and cattle is panting.
• Do not spray a sheep with cold water to attempt to cool them. While this is beneficial for most animals, if the wool gets wet, air will not pass over the skin and virtually no cooling will occur.
• Don't over-exercise or transport livestock during the hottest part of the day.
• When cooling down sows, be sure to keep piglets dry. Piglets require the heat.
• Pigs do not sweat like other animals and will try to cool down by wallowing in water and mud to cool themselves. Provide a cool surface for pigs to lie on. Use a water sprinkler for 1 to 2 minutes every 20-30 minutes to help keep pigs cool as possible through evaporation.

When dealing with potential heat stress on livestock, people should keep in mind the weather factors contributing to heat stress and exactly how heat stress works. Most people don’t measure humidity when it comes to determining the heat stress threshold of their livestock. Heat stress is brought about largely by a combination of temperature and humidity (what is referred to as the Temperature Humidity Index) and it doesn't take much of an increase in the THI to place an animal in a potential health risk.

In addition, our animals are also affected by the very smoky conditions and avoiding strenuous activity is a good idea until the air quality improves.

If an animal is breathing with difficultly, appears distressed, becomes weak, or develops diarrhea, seek veterinarian medical treatment.

For more information about specific animal questions and concerns, contact your veterinarian.