Help horses keep their cool when heat is on

Summer will soon officially arrive, bringing the challenge of managing horses during hot weath­er. Horses can acclimate to hot and humid environments. A 15-day to 21-day acclimation period is recommended for horses originat­ing from cooler or drier climates that are traveling to compete or reside in hot, humid conditions. The acclimation period results in an increased tolerance to both heat and exercise. However, acclimation does not reduce the need for close moni­toring of horses during training and competition in these environments.

To help reduce the effects of heat and keep horses comfortable, con­sider the following:

• Provide turnout during cooler times of the day—early in the morning, late at night or over­night.
• Provide relief from the sun through access to shade from trees or buildings. Remember that shade will change throughout the day, and constructed buildings may block natural air flow.
• Watch for signs of sunburn, especially on white or light-col­ored areas. Use masks to protect the horses’ faces.
• Fans help to improve airflow, but be sure to keep cords and plugs out of the horse’s reach to prevent electrocution.
• Ensure access to clean, cool water at all times. “Cool” is de­fined as being 45 to 64 degrees. Depending on feed, an adult horse in a cool climate will nor­mally drink 6 to 10 gallons of water each day while at rest and much more while working or in situations with high heat and humidity.
• Water buckets and tanks may need to be cleaned more regu­larly in hot weather as algae and bacteria grow rapidly in warm water. Blue algae toxicity is more common in ponds or slow-run­ning streams during hot, dry weather.
• Free-choice access to salt will encourage drinking. The two electrolytes that most often need to be replaced from sweating are sodium and chloride, which make up salt. Loose salt is pre­ferred to a salt block. Offering free-choice MFA 5% Horse Mineral with Shield also helps to mitigate heat stress. It contains salt as well as essential oils and a proprietary blend of botanical extracts and synbiotics, all of which help boost the horse’s health and immune system.
• Consider providing electrolytes to horses that have been sweat­ing heavily or are expected to do so. If electrolytes are added to drinking water, also offer plain water since some horses dislike the taste of electrolytes and will drink less. This situation is sim­ilar with people—some like to drink Gatorade. Others do not.
• Reduce riding intensity and length. Heat stress can affect any horse but is especially common in older, obese and out-of-con­dition horses. Young foals also tend to be more prone to heat stress and dehydration.
• Clip horses with long hair coats, such as horses with Cushing’s disease, to enhance cooling.
• Transport horses during the coolest part of the day. Ensure that trailers are well ventilated. Offer water frequently. Do not park in direct sunlight with horses inside.
• Horses that have little or no ability to produce sweat have a condition called “anhidrosis-hypohidrosis,” and are prime candidates for heat stress. Re­search shows 2% to 6% of hors­es can develop this issue. They may require additional manage­ment strategies to mitigate the effects of heat stress, such as electrolyte therapy.
• Avoid riding a horse when the combined temperature in degrees Fahrenheit and percent relative humidity is greater than 150. For example, if it is 80 degrees out, a relative humidity of greater than 70% exceeds the 150 calculation.

If a horse must be worked during hot and humid weather, consider adjusting your schedule to ride ear­ly in the morning or late at night. Work the horse in shade when possible, and keep the work light. Include frequent breaks that allow the horse to cool down and regain a normal respiratory rate. Do not work the horse beyond its fitness level. Watch for normal sweating. Inside the stable, create airflow, use fans and exploit the “chimney effect,” in which rising warm air forces cooler air to infiltrate through doors, windows or other openings. Provide access to cool, clean water at all times and offer water fre­quently during work.