Heat Exhaustion Treatment

1. CHECK VITALS Check the rectal temperature, the number of heart beats per minute, the number of breaths per minute, and listen to the abdomen for gut sounds and write all your findings. Re-check every half hour and record your progress. The normal temperature is 99-100.5°ree; F. The normal number of heart beats is 32-44 beats/min (adult). The normal respiratory rate is 8-15 breaths/min.
2. ELECTROLYTES AND FLUIDS Gently but persistently get electrolytes and fluids into the horse orally. If he won't eat or drink voluntarily, you'll have to use some initiative to coax him.
   • Offer a bucket containing a half gallon of plain, cool (not cold) water and, right next to it, a second bucket containing a half gallon of electrolyte-treated water using a commercially prepared electrolyte powder designed specifically for endurance horses. Do not , under any circumstances, give this horse an electrolyte product made for calves or foals with scours (diarrhea) or for sprinting-activity performance horses&mdahs;the sodium bicarbonate in these products can make his heart unstable, and it can guarantee that he will be stricken with myositis on top of all his other problems.
   • If he shows no interest, rinse his mouth gently with a 20 cc syringe full of electrolyte-treated water, then offer the buckets again.
   • If he still shows no interest, you'll have to force him. Remember, he's still losing more water and electrolytes, probably a gallon or more per hour, even though he's just standing there—they're literally pouring out of him in his sweat and in his breath.
   • Start with the elctrolytes first. Read the instructions on the label of your elctrolyte product and calculate how much of the product would be required to prepare one quart of treated water. Mix the calculated amount with something yummy, then give him your concoction with the syringe. Still no luck? Then you need to be more aggressive. Give him one cup of water, by syringe, every five minutes, and give him another dose of elctrolyte mix, by syringe, every half hour. Do this for 2 hours, or until he begins drinking on his own.
   • If you don't have an elctrolyte powder, you can make your own concoction with ingredients you can buy at any grocery store:
     

     1 tablespoon regular table salt (sodium chloride) 1 tablespoon Morton's salt substitue (potassium chrolide)
     2 crushed tablets of extra-strength TUMS_TM (calcium carbonate)
     500 mg (2 crushed 250-mg tablets) of magnesium pills (magnesium oxide)
     2 tablespoons Karo syrup or honey or molasses or pancake syrup
     1 jar of baby food
     

3. COOL HIM Meanwhile, be working on bringing his body temperature down by swabbing him every ten minutes with cool (not cold), dripping-wet cloths over his body, being sure to get him behind and between his ears, on his forehead, and on the underside of his neck, and in his armpits and groin. Do not run cold hose water over his back and rump—you could cause the blood vessels in those muscles to clamp closed even more than they already are, which will slow down his heat dissipation and threaten myositis.
4. GIVE ASPIRIN As soon as you see signs of improvement: a bright look in the eye, heart rate beginning to drop to within normal range, respiratory panting beginning to resolve, body temperature coming back down to earth, and a return to voluntary eating and drinking, give a tiny dose of aspirin paste or gel orally to relieve residual muscle pain, encourage the still-spasming muscles to relax, and guard against the damaging effects of inflammation and toxicosis.
5. MUSCLE TREATMENT If your horse is showing any signs of impending myositis (stiffening gait, tight or hard-feeling muscles over his back, croup, and loins, and/or coffee-colored urine), or if he has a history of tying-up in the past, he might benefit from a judicial dose of a medication that will help to dilate the constricted blood vessels in his major muscles. Again, if he is in a very tough shape, he might not be able to tolerate any medication smoothly. Rule of thumb: if he's eating and drinking well on his own, and he seems to be showing general signs of recovery, he should be able to tolerate the medication.

References: Emergency! by Karen Hayes, D.V.M.