As summer reaches peak intensity, health conditions like colic, heat stroke and heat dehydration can affect your horse. Learn how to prevent colic, heat stroke and heat dhydration in your horse this summer.
Colic: The combination of lowered moisture levels in the grass, higher indigestible fiber in mature grasses, lack of rain leaving pastures parched, water and electrolyte losses in sweat, and water consumption dropping when water sources are not regularly cleaned can, and does, lead very quickly to problems with impaction colic in late summer. Your major defense is to guarantee that your horse has an abundant supply of clean water.
Horses prefer their water lukewarm, at about body temperature, not overheated and certainly not teaming with organisms/algae because their troughs are not regularly cleaned. A good rule of thumb is that if you wouldn't drink it yourself, you shouldn't expect your horse to either.
For reasons that are not understood, some horses also will tend to show colic when a storm is approaching. This almost certainly has something to do with their nervous system (which also controls gut function), but the details aren't clear. If your horse seems to show this pattern, talk to your vet about the possibility of keeping medication on hand (e.g., Banamine) to treat this early before it becomes a problem.
Heat exhaustion/heat stroke: Horses are not well adapted to heat. Avoid working your horse during the hottest part of the day.
Also, it's extremely important to guarantee the horse is getting adequate clean water (see above) and also salt. For horses not being regularly worked, add at least 1 oz./day of salt to their feeds and keep salt available free choice at all times. For horses who are being exercised, use 2 oz./day in the feed plus free-choice salt. Horses working long hours or at high speed can also benefit from addition of an electrolyte supplement that carefully matches sweat loss, to be given after exercise on those hard workdays. But do not substitute electrolyte mixes for plain salt.
Breathing: Horses with nasal, sinus or lung allergies (actually, these usually go hand in hand) really suffer the most on days that are very hot-worse yet, hot and humid. The mucus production may be so heavy that they are misdiagnosed as having lung infections, but the response to antibiotics will be poor to nonexistent, they will have no fever, and white counts will be normal. Symptoms include any or all of the following: cough, dull attitude, clear to white, thin or frothy nasal discharge, poor exercise tolerance, excessive blowing, elevated breathing rate.
Keep the horse in the coolest area possible, with the best air circulation. Mentholated rubs, like Vicks VapoRub, are helpful in preventing buildup of thick mucus that makes it difficult to breathe. Once trouble with breathing becomes obvious, the horse will likely need drugs like antihistamines, bronchodilators, maybe corticosteroids, for the remainder of the hot, oppressive weather, but will improve dramatically in the fall. If started early, antioxidant supplements may help minimize symptoms the next year.