Animals and hot weather


By Jerry Mahan



The past few days the weather has been a topic of discussion related to both animals and people. The hot weather and high humidity are a double whammy on the health and stress of animals and all of us. People have the option of getting water to drink or utilizing air conditioning where animals depend on us for water and shade in many cases.

During the county fair one of the important responsibilities in taking care of your animals includes providing water and shade where possible. This is not a once a day routine but must be done several times at the fair. The animals must cope with different smells, tastes of city water, noise, strange people and other animals as well as a change in environment. They are at our mercy.

Below is an article I wrote several years ago and have updated. It is still relevant for our animals regardless of whether they are at the fair or at home. For more information on cooling animals consult with your veterinarian or department leader at the fair for help.

Animals like people suffer through the hot humid weather. What we forget many times is that not all animals deal with heat in the same way as people. Many do not sweat and must depend on breezes, cold water or cool surroundings to deal with the heat.

Being able to get out of the sun on hot days is extremely important for most animals to survive. In general hogs, chickens, cattle (most European breeds), dogs, cats and rabbits do not have sweat glands in their skin while horses are more like humans. Sheep and goats do sweat but most temperature change is done through panting. Animals which do not have sweat glands in their skin lose heat by panting, through their paws as in cats or through contact with their environment.

Animals need a lot of clean water each day depending on air temperatures and humidity. For example milking cows need 35-45 gallons per day, market hogs 6-10 gallons per day, beef animals 8-12 gallons per day, sheep & goats 2-3 gallons per day, horses 12 gallons per day, 100 chickens 9 gallons per day, 100 turkeys 15 gallons per day and dogs up to a few gallons per day depending on size.

We all know the stress put on us as a result of the hot humid weather. Let’s not forget to take care of our animals. By necessity animals need a good supply of clean, fresh water at all times. Shade is important as well with good ventilation.

This shade could be a building or tree. Checking on animals/livestock daily or several times each day at the fair is important to help locate animals having problems. Animals suffering from heat exhaustion may have rapid breathing, be weak, panting and have muscle tremors or not moving around at all.

Animals can cool themselves or lose body heat in four ways — conduction, radiation, convection, and evaporation.

Conduction heat accounts for 10-15 percent of total animal heat loss and can affect growth and comfort. Dissipation of heat by conduction is by direct contact with a cooler surface such as a concrete floor or sawdust which can be made cooler with water.

Radiant heat loss accounts for about 30 percent of the total heat loss and is primarily determined by the temperature of walls and ceilings. When the surfaces are cooler than the animal, the heat loss will increase as the temperature difference increases.

Convection heat loss occurs as the animal’s body warms the air around it. The warmer air is replaced by cooler air as the air is moved by natural breezes and/or fans. The building ventilation is important to this method of heat loss. Up to 35 percent of the heat loss can occur through convection.

Evaporation heat loss typically accounts for 15-20 percent of an animal’s heat loss but can be as much as 40-50 percent of the total at very high temperatures. Some animals such as hogs, cattle, dogs, and chickens, do not sweat as we do so in warmer weather they must dissipate heat through their skin as well as increased evaporative cooling.

The panting dog’s tongue is a mechanism for evaporation heat loss. Cool (not cold) water sprinkled over an animal can help the cooling process in extreme cases. High air flow rates around animals will increase the cooling effect of evaporation when water is on an animal’s skin.

Some additional management tips for cooling include providing shade or areas where animals can get out of the sun. Remember areas with shade in the morning may not have shade in the afternoon.

Keeping clean, cool, fresh water in front of animals is critical! For some animals, fans may be needed to increase air movement for additional cooling. If animals are to be moved, the early morning is the best time as this is the coolest time of the day. It is also when the body temperature of the animal is the lowest.

The ability of the animal to lose heat is also affected by grooming and showing practices. Heavy hair coats, blankets, and grooming preparations applied to the hair and skin will reduce heat loss by several of the mechanisms listed above. Caution is in order when using these grooming aids if there is any concern about heat stress.

In extreme cases, both rabbits and chickens can be immersed in cool water up to their heads to bring body temperature back to normal if suffering from heat exhaustion. Plastic pop bottles filled with frozen water can be helpful to rabbits as well as sprinkling them with water on very hot humid days. Since rabbits lose a lot of heat through their ears we can cool the animal by putting water on the ears, being careful not to get it in them. Cold water is usually reserved for animals suffering heat stroke and collapse.

This article is based on information supplied by Veterinary Associates and the OSU Veterinary Extension Department.

By Jerry Mahan

Jerry Mahan is a retired agriculture educator and guest columnist. Contact him by email at: mahan.2@att.net.

Jerry Mahan is a retired agriculture educator and guest columnist. Contact him by email at: mahan.2@att.net.