Hot Weather Riding - Dehydration in Humans and Horses

I usually write an article in the beginning of Spring to get readers thinking about the coming hot months and the threat of dehydration, for both you and your horses. I'm late this year as 90 degree plus weather has been in Texas for over a month, but here it is anyway. Dehydration, of course, if when the loss of bodily fluids, think sweat, exceed what we take in through drinking. Not only do people and horses sweat away fluids, we also lose a little through normal breathing. We also lose electrolytes, such as salt, as well.

Some people wake in the mornings after 6 or 8 hours of sleep, throw feed to thir horses, drink a cup of coffee (a dietetic), tack up then ride, and it may have been 12 hours or so since they last drank any water. And make no mistake, coffee, tea, soda pop, etc., are not replacements for water.

And not only that, most people do not take water with them when they are riding, but some people will go to the trouble of taking a energy drink or diet soda with them. Same as coffee and tea, but even worse, energy drinks and diet sodas are not replacements for water - they will dehydrate you quicker.

I rarely ride in the hot weather without a canteen looped around the horn or without a Camel-Bak. Camel-Bak are the makers of the original hydration packs and offer a huge selection from waist band packs to full size back pack with hydration bladders. When I'm working with Search and Rescue Team on a tracking course, I recommend that they carry hydration packs, and to consider Camel-Bak's in the rescue yellow color for visibility on the ground or from the air. Check out the offerings from Camel-Bak here.

Getting a headache, feeling tired or weak, and not having to urinate or having dark colored urine are all signs of the beginnings of dehydration. These symptoms can be reversed with the consumption of water.

When dehydration gets worse, dizziness and even fainting, having a pounding heart beat, and when you stop sweating are all signs that you are approaching a no return point. Medical intervention, usually through intravenous fluids are necessary. This is a medical emergency as severe dehydration will cause death.

Dehydration in our horses is the same excessive loss of water without replacement that we experience. In my mind it is usually caused when we do not provide clean drinking water, or work them too hard in hot weather sometimes after feeding them but not allowing the time if takes for them to get a drink.

Horses may show the same lethargy as humans when dehydrated. They may have a lack of saliva in their mouths and a dullness in their eyes. Other tells on a dehydrated horse can be a slower capillary refill response, higher heart rate, rapid and shallow breathing, and, lack of skin elasticity.

Slower capillary refill response can be determined by pressing on the gums with your thumb. This will push the blood out of the tissue area that you are pressing on, then when you release, the gum should immediately (within a second) go back to it's normal (darker) color as blood refills into that tissue. The longer it takes, the more dehydrated your horse is.  The picture at right shows the area of the gum above the front teeth, a good place to do the capillary refill test.  

Higher heart rate. A horse's normal resting heart rate is around 40 beats a minute, probably less for a well conditioned horse. A resting heart rate significantly above that, say above 50 beats a minute can be a tell for dehydration.

Rapid and shallow breathing. Often a sign of other distress, such as colic or pain, rapid and shallow breathing can indicate dehydration. If your horse is not in distress, a normal breathing rate is around 10-12 breaths a minute.

Lack of skin elasticity. This is the skin fold test. On the horse's chest or neck, pinch some skin between your thumb and forefinger then release. The skins should return to normal immediately. If the skin stays "tented" for any length of time, certainly more than a second or two, then your horse is more than likely dehydrated.  The picture at left shows pinching the skin on the neck to check for skin elasticity. 


I think it helps to know your horses eating and drinking habits. For example how much water they drink during the day during certain temperature conditions. And what their drinking habits are as well. All horses are different. I have three main saddle horses. Each usually takes around 2 hours to finish their morning feed, then they will usually rest for 15-30 minutes before they ever mosey over to the stock tank for a drink. I use stock tanks as opposed to an automatic waterer so I can tell how much they drink or even if they have drank. Sometimes, I can shorten this time frame but leading a horse to the stock tank and after a few minutes they will usually drop their heads to drink.

I think most people know that you don't allow a hot horse to drink or eat, until they have had a chance to cool down. Nor should you wash off a hot horse, although I'll often use a wet sponge on a horse, but only after he has had a chance to stand and get his respirations back to normal.  So keeping them tied to the rail while they cool down and you do your post ride grooming is always a good idea. And while horses also lose electrolytes as they sweat, a free choice salt and/or mineral block in their en is also something to consider. Safe Journey.