During a heavy or extended workout, your horse will lose water through sweat, a function by which the body cools itself. This water loss, if not replaced, reduces the horse's internal supply and creates dehydration. In addition, the excessive loss of fluids flushes important minerals, proteins and electrolytes from the body. Thick, sticky sweat indicates a heavy concentration of protein and mineral loss. Thin, watery sweat is a result of good conditioning and an adjustment of the horse's internal system to junction well under stress. Endurance and competition riders often give electrolytes to their horses in their water or in a paste from, during strenuous conditioning and competition, especially on hot, humid days to make up for any losses due to sweating.
Of course, the first step in preventing dehydration and the loss of important body electrolytes is to provide clean fresh drinking water. During exercise, internal body water is diverted to the working muscles and away from the intestines, as more blood rushes to the exerting muscles. There is, thus, a reduction in gut activity. Some experts speculate that fluid taken in during heavy activity is not absorbed as quickly as was originally believed, due to the temporary slowing down of the intestines. The shock of rapid consumption cold water has been the cause of colic in some horses, during or after exercise. To be on the safe side, set a couple of buckets of water out in the sun before you start exercising your horse. Let the sun warm it to air temperature, before offering it to your horse. The idea is to prevent dehydration rather than have to treat colic.
The simple "pinch test" can indicate dehydration. Pinch up a fold of skin at the point of the shoulder or on the horse's neck close to the shoulder. Let go and count the number of seconds it takes for the skin to flatten. The skin can snap quickly back into place indicating that the horse is not dehydrated or can take one to two seconds to flatten indicating some dehydration. When the skin takes more than three seconds to flatten, you should be very concerned for your horse could be quite dehydrated.
Your horse's diet should be examined for proper balance of calcium and other minerals. This electrolyte balance in the daily ration is quite important. a normal horse can maintain the proper electrolyte balance without supplements, but a horse that is asked to exert more energy, and thus sweats more whether for endurance or competitive trail rides. The balance can be altered. Horses involved in long-term, higher intensity work may lose electrolytes via the sweat at a rapid rate, and the sudden decrease in electrolytes can cause the muscle problems and heat stress injuries.
At present there is not enough known about electrolyte use in the horse's body, but several serious conditions are related to an improper balance. Exertional rhabdomyolysis is considered more common than "thumps," exertional rhabdomyolysis can be described as the seizure of the muscles in the hindquarters The key to prevention, as with thumps, muscle tremors, and the overall condition of exhaustion, is conditioning and diet.
Gail Ecker of the Equine Research Center offers the following ways in which you can help prevent dehydration and electrolyte loss in your horse during competitive and endurance rides.
1. During the week, make sure the horse has a high quality diet and add electrolytes only if the horse has been working hard enough to cause moderate to high sweat loss. The normal losses of minerals during less strenuous exercise is replaced with good quality mixed concentrated grains and hay. Always make sure that the horse has a clean salt block. Some owners provide free-running salt and minerals, which is easier for the horse to eat. Excess electrolyte supplements during the week will not be stored up for a competition and is not advised.
2. Feeding hay for to five hours before the beginning of a competition may increase the water in the horse's gut, which would then be available to the horse when water loss due to sweating begins. One to two hours before the event (or before a long trailer ride), it may be beneficial to give the horse a dose of electrolytes to build up a reserve in the gut.
3. Do not give electrolytes to a horse that is already dehydrated. A high amount in the gut may actually pull water from the blood, increasing the dehydration of the body. Try to get the horse to drink about four gallons of water before or after a dose of electrolytes.
4. Give water and electrolytes early in an endurance ride or when you know the horse will be needing them. When you increase the horse's sodium level, the horse may start drinking sooner as a result. If the weather is hot, don't wait until the horse shows signs of dehydration before giving electrolytes. If you wait, the horse will have some level of dehydration by that time and less blood is available to the gut for normal function.
5. Once the competition is over, do not stop giving electrolytes. The horse may still be sweating for some time after the event to reduce body temperature. If the horse consumes water only, this can actually "dilute" the blood, further lowering the electrolytes concentrations in the blood's plasma.
Be sure that you are helping the horse to cool himself. The less he has to sweat, less electrolytes will be lost.
Ask your Veterinarian to teach you to perform skin pinch, capillary and jugular refill and mucous membrane testing, as well as listening for gut sounds. These will help you to determine, if the horse needs more electrolytes and water. If these indicators are not showing an improvement about half an hour after the horse has had water and electrolytes, then a second dose of electrolytes may be necessary as long as the horse has had a good drink of water.
Frequent small doses of supplements are better than one or two large doses.
If your horse refuses to drink even though you have given it lots of time, you might try putting a tablespoon of salt onto the tongue or into the lip of the horse. The salty taste sometimes causes the horse to start drinking.
If you are new to competitive trail rides and endurance, which might require supplementation of electrolytes, discuss these needs with your Veterinarian and with other riders who have been competing successfully. Their methods will not be exactly what your horse needs, but it will give you a place to start and with practice you will learn to adjust the dosages to suit the needs of your horse.
c)2001 by Karen Murray. All rights reserved.
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