Managing Event Horses In The Heat At Shows

Managing Event Horses In The Heat At Shows – written by Karen Nyrop

Horses are superior athletes when compared to humans. Horses can sweat twice as much, can loose twice the amount of body water before fatigue, and have twice the metabolic capacity for work.
-the increased sweating is enabled by the large reservoir of fluid and electrolytes in the gastrointestinal tract. In high intensity work, the fluids in the gut can be used by the horse to augment blood volume.
-the increased work capacity is due to the huge muscle mass of horses when compared to man.
-however, the horse has a 50% lower body to skin surface area ratio than man which is very important to a horse working hard. This means that there is less skin surface area per pound of horse available to loose heat produced from exercise. So, the lower the ratio, the harder it is to get rid of stored heat built up from exercise.

Exercise, Heat and the Horse

Of the energy produced during exercise, the horse only uses 20% of that energy for work. The other 80% is released as heat. Because of the large muscle mass in horses, this heat would build up rapidly if they were not allowed or able to cool.
Cooling horses comes from four sources, this is the transfer of heat from the horse to the environment.
– Convection-heat transferbetween hot skin and cold water-can be very efficient in cooling event horses if done properly
-Conduction-direct transfer of heat between surfaces in contact-hot skin cools when a cold, wet towel is put on the horse…not efficient as the towels heat up fast and actually act as an insulator and hold the heat in.
-radiation- heat emitted from the body surface- not efficient in hot and humid conditions
-evaporation-basically, sweating. Efficiency depends on the environmental heat and humidity. However, without our help, sweating is the best way for horses to cool.

Horses can also loose heat by panting, like a dog. That is also evaporative cooling. It is important to learn the difference between a horse panting to lose heat and a horse “puffing” from exercise and breathing fast due to the exercise it just finished.

So, what does this mean for our horses competing on a hot and humid day? When horses exercise hard, their internal body temperature goes up one degree C for each eight minutes of work. In hot conditions, it can go up two times as fast. Sweating is not enough to cool the horse rapidly. In conditions of hot and humid weather, we must help our horses cool quickly after intense exercise. Which horses need rapid cooling? You should take your horses’ rectal temperature to document his heat load. If his rectal temperature is 40C, his internal muscle temperature is one degree C hotter. That means 41C. If you rapidly cool a horse (we will talk about how to do this next), you can get their rectal temperature down two degrees C in 10 minutes. At the top levels of our sport, most horses will have rectal temperatures of 39-42C after cross country, some will be higher. At the lower levels and the three day format horses, the rectal temperature will likely be 38-40C. These are not alarming numbers, but it is still useful to help the horse cool if the ambient air conditions are hot and humid. Often, the rectal temperature may go up in the first 10 minutes after cross country. This is due to heat conduction from the warmer muscles to the cooler parts of the body as part of the horses’ effort to cool. While this works, as we already said, this is not very efficient to cool a horse in hot and humid conditions.

How do we rapidly cool a hot horse?
First, take the horses’ rectal temperature. Remove the tack and put on a halter.
Second, use sponges to put cold water on the horse. Sponge it all over the horses’ body. You will feel that the skin is very hot, then cooler when you put on the ice water. When the water on the horse gets hot, scrape it off with a sweat scraper. Apply more cold water immediately. Keep doing this until your horses’ skin feels cooler and the veins no longer stand out on the skin. ****you will not cause tight muscles by putting water on their back or hind quarters****the quickest way to cool your horse is to put water all over their body, scrape, and reapply.

Take the horses’ temperature every ten minutes. If he is cooling properly, he will want to graze, his skin will be cool, heart rate will decrease, and his temperature will be decreasing.
There may be big fans at the end of XC. While they help to cool a horse, you actually cool a horse better and faster by using the cold water method described above. If there is shade in the area, try to sponge your horse off in the shady area, then walk him a bit, scrape, and reapply cold water, as needed.

Electrolytes, Sweat, and Horses and Travel

Horses sweat has a lot more electrolytes in it that humans. It is important to keep their electrolytes in balance from the time you leave home until the time you return home. The very best way to do this is to provide hay, water, and salt to the horses at all times. The salt can be in a block or loose. It should have Sodium, potassium, and chloride in the salts. Not just sodium chloride (table salt). The food in your horses’ gut acts as a reservoir to hold the electrolytes and then they are absorbed when needed by the horse. Be careful if you choose to supplement electrolytes to your horse at competitions. If you give them a lot of extra electrolytes (as a paste preparation, typically), and the horse is already dehydrated, you can make their dehydration worse because all the electrolytes stay in the gut. These pastes can be used to encourage a horse to drink more water, but they should not be given to a horse that is already dehydrated. Consult with your horse show veterinarian about the use of these products if you are concerned.

The best way to introduce more salt in their diet is to begin before you leave home, or before the competition begins. This allows the horses system to get used to the increase of salts and be useful for them when they really need it. If you give extra salts to them all the time, their body gets used to the extra and the kidneys filter out the extra salts daily. So, increase the salts for about a 5-7 day period around the competition to allow the horse to best use the electrolytes.

Some horses do not readily drink strange water at a show. You can help them get used to drinking away from home by having them drink out of buckets at home before you leave. You can also lightly flavor the water using a few drops of peppermint, or vanilla in the water buckets. Hopefully, you can “trick” them into drinking strange water by adding the flavor at the show…the same as you have done at home.

During travel, do not be alarmed if horses do not drink for eight hours. It seems that they don’t feel the need to drink right away when travelling. Many horses do, however eat whatever you put in front of them! I do not feed huge amounts of hay when travelling until they begin to drink better when on the road. Horses can develop impaction colic from lots of hay and not drinking enough to properly digest the dry food fed to them. You can also wet the hay to get a bit of moisture into the horse as he travels. This also helps to keep the dust level down in the trailer.

This is a brief introduction to managing horses at show in hot and humid conditions. Practice the cooling methods described and your horses should cool very well.