Horses and the Heat: Too Hot to Ride?

Charlotte wrote to ask about how much heat can her horse handle being ridden in. " I've found a couple of your articles about horse dehydration and people getting heat stroke but my question is how hot can it be where I can still reasonably ride my horse. I know her health is important but she seems so sluggish in the really hot weather like high 90's and I don't want to hurt her but only my riding times are generally in the late afternoon when it is still very hot."

I think horses generally do much better than we do in the heat and much better than we give them credit for. However, I would never fault anyone for being too cautious considering their horse. I have cut short trail rides when someone thinks their horse is off - better to be safe than sorry. But again, horses do pretty well in the heat, given a horse in good health and condition, and acclimatized to that environment. Horses will lose fluids and electrolytes by sweating, same as humans do, but horses drawing fluids away from their guts is a bigger concern for them than the human. I know some people who clip their horses in the Spring when temps are in the 70-'s to 80's thinking a lighter coat of hair will minimize over heating. Heck, my horses generally don't start shedding their winter coats until temps are in the 90's and I ride them without worry, but they are acclimatized to this environment. The biggest problem I have is that hair shedding season coincides with the windy season here in West Texas, so much of the shedding hair is blown into my face and mustache.....pretty much like the universal rule that all spider webs are mustache high.

We generally find our limits, and therefore our horses limits, by experience. Years ago, I have taken horses, maybe as young as 5 years old and as old as 14, out in 100 heat and covered 15-20 miles over 6 or 8 hours without access to water and did not have issues - I wasn't doing this for pleasure, it was for work. These days I'd have to have a reason for pushing a horse that hard. Not having a drink all day, the horses were obviously all in some state of dehydration when we finished. I'd always pull the saddle and let the wind coming through the trailer on the ride home evaporate cool them somewhat. My practice is to cool them off then put them back into a pen where they would always roll first, then look in their feed bin second, before they would seek water. If a horse is not finished with their feed before I pull them for a ride, it's usually a good indicator that they haven't gotten a drink, so when I return from a ride I'll pull their feed so they can get a drink before resuming eating. Sometimes I'll wait for 20-30 minutes as well. I'll also use a wet brush, sponge or rag and wipe my horse's neck, chest and legs down which helps, or at least I think it does, with some evaporative cooling effect.

This time of year in the West Texas desert, it'll still be 100 degrees at 7 pm. I have no problem riding my horses for an hour or two then. If I was riding a few hours earlier in the same temperature range, I'd likely be a little more concerned as the Sun is closer to being directly overhead and the solar radiation is stronger, so you'll feel the effects quicker. Intensity or work and duration will be a key factor - the harder and longer a horse has to work, the hotter the horse will get, and therefore the sweating rate will go up to regulate body temperature. The horse's body will send more blood to the skin, depleting blood and water from the internal organs and gut. That's why excessively walking a colicing horse can have adverse effects. A horse with a over heating issue will have more rapid breathing and a higher heart rate, and likely an increase temperature. Just like a human, once a horse gets a heat injury, the easier or faster it will come next time.

If you have read other articles on riding in hot weather then you pretty much know how to check your horse for dehydration, with the skin pinch or capillary refill test, or can see when a horse is drawn up and tight. Plus the more you ride a particular horse the better you can tell when he is a little off. I would suggest checking all your horses at rest and after moderate exercise to get some baseline observations and numbers for each. You also don't want to take his temperature for the first time when he is heat stressed. Just know before hand what a normal horse looks like. Ask the same questions to your Vet the next time you have the Vet out, and maybe some other riders in your area.

Feed can have an impact on how hot a horse gets. I feed a mix of Bermuda grass, sometimes timothy grass, and alfalfa hay. My horses also have free access to plain white salt blocks, mineral rocks and fresh clean water. I used to give wheat bran mashes to help counter the ingestion of sand but since I obtained big box feeders my horses rarely pull or drop alfalfa onto the sandy ground. If a horse eats off the ground in sandy environments a lot of sand can be ingested. You may see watery piles as the body pulls water and blood to the gut to help push it out. When I get called to help someone and a colicing horse, because it's usually Friday night and Vet's are hard to find, it's almost a sure thing that their feeding program has some sort of negative influence....it's just hard to pinpoint it as there are many ways to prepare feeds and every horse is different. Running a public barn for years, I saw quite a bit of strange feeding habits and the resulting issue on a horse......feeding beet pulp and not soaking it sufficiently (I will not ever use beet pulp - nothing against those who do, I just don't have a need to feed it); a straight alfalfa diet; 17 quart buckets full of dry alfalfa cubes; dirty stock tanks that even a old catfish wouldn't swim in.

Again, I think you are doing the right thing on considering the well being of your horse, and you didn't say how old your horse is. Maybe riding her with an increase in intensity over time can set some boundaries for you and her. Are you feeding your horse just before you ride her? She may resent coming off her feed, or feel lethargic with a full belly.  If your horse is healthy and well broke, her sluggishness just may her trying to get away with doing as little as required.......my wife accuses me of that quite a bit.

More on Horse Dehydration and Water Needs

Mac wrote in regarding dehydration in horses: "Great article on dehydration in Horses and Humans. I know people can go a maximum of three days without water, so my questions are how much water does an average horse need for one day, how long can a horse go without water like in the heat of the summer, how can you get horses to drink more water?"

While it is true that 48 to 72 hours is generally considered to be the maximum time a person can go without water there are several factors that would extend or reduce this timeline such as ambient temperature, exposure to the Sun and the individual's physical condition. But well before that individual would actually die from dehydration, his or her ability to think coherantly and physically function would be greatly reduced. At some point, likely hours, before actual death from dehydration if someone found the individual, he/she would likely be too far gone to save with oral re-hydration.

So I think these questions are the revelant ones: 1 -  How long can a person or horse go without water before their physical ability and mental reasoning is signifcantly degraded; 2 - At what point or time without water does an individual or horse become on a shortr spiral to death without extraordinaty life savings measures; 3 - then the question of how long can an indvidiaul or horse go without water before dying becomes kinda non-relevant.

Someone sent me a chart or meme with a picture of a horse and a quote to the effect that horse's need eight gallons of water a day. I'm sure it was intended to make owners more aware of a horse's water needs, but eight gallons per horse per day is a minimal amount in my opinion, maybe excepting in cooler temperatures.

I know of four horses that have traveled 60 miles in 50 to 70 degree weather with heavy loads - saddle and rider on one horse, and saddles with a hundred and fifty pounds of marijuana on the other three horses - all without access to water, and at the end of the second day, the rider leading the string rode into a ranch and asked the people there to call the Border Patrol. The rancher took care of the horse, giving them water before turning them over to the Tick Rider, and all horses survived. If the temperature would have been twenty degrees hotter, then this story would have likely had a different ending.

Probably the closet I've came to testing one of my horses to his limit was chasing a someone's loose horse for 17 miles in over 100 degree temperature. Once I got my horse back to his pen he was more interested in feed than water, but once I had them cooled off, I'll give him a chance to drink for 30-45 minutes before feeding him. If he still has not drank and water, sometimes I'll soak some alfalfa in water and let him have that.

And you asked about how to get a horse to drink more water? I'd like to know myself. But what I do if one of my horses is finished eating, and I'm waiting on him, I'll lead him over to the stock tank. If I'm patient enough, he'll usually drink a little which makes me feel better about taking him out for some work.  In some cases if I'm needing to get him to work, I'll give him water soaked hay, like I mentioned above.  All horses are going to be a little different, watch them for a few hours and you can see what their tendencies are.

To address your question on how much water a horse needs daily, again you have to consider the horse, the activity, his physical condition and the ambient temperature. To give you an example using one of my horses, who is in very good condition, in temperatures from 76 degrees to 105 degrees this is his water use over two days:

Day One,
Midnight to 0530, my horse drank 2 gallons of water
0530 fed him
0830 saddled up, loaded and on the road
1000 horse unloaded and rode doing ranch sorting until 1300 then loaded back up and on the way home
1430 back home in the pen, offered water, horse drank maybe 1/2 gallon. I did a skin fold test - skin on neck stayed tented for 5-6 seconds indicating pretty well dehyrdated. I hosed him off with cool water then put him back in his pen.  The pictures at right show the skin fold test on the loose skin on his neck.  Sorry about the poor quality picture at bottom, but I think you can see the skin staying "tented" which is a pretty good indication that he is dehydrated to some extent. 
1450 horse fed
By 1800 the horse had finished his feed and drank almost 9 gallons of water
1830 fed again and by midnight he had drank more 4 gallons of water

Day Two,
Midnight to 0530 he drank another 2 gallons
0530 fed
0830 He had drank another gallon. I saddled him and rode about 5 miles in 90 degree heat and direct sunlight.
1100 He was back in his pen and I did another skin fold test with his skin staying tented for less than 2 seconds. So I left him to drink and wait until his mid-day feeding.
1330 Went to feed and noted that he drank 3 gallons
1330 Fed him
By 1800 He drank 5 more gallons of waters.
1800 to midnight, he drank maybe 1 more gallon of water.

So in two days, in day temperatures over 100 degrees with moderate work, this horse drank just a little more than 27 gallons of water.

Providing adequate amounts of clean water for horses is likely the biggest failure of most people I see keeping their horses in pens.  Getting asked to look at suspected horse abuse I most often see horses without adequate water at all.  I advise owners that they should plan on their horses needing 15 gallons of water, per horse, per day at a minimum. This is pretty consistent with my two days of measuring on one of my horses. All my horses have overhead cover to protect them from the direct Sun if they seek it. Many horses are kept in facilities without over head cover so I would think their water needs may be greater.

Judging Your Horse's Manure

If you are like me, you are always evaluating your horse's manure, whether in a stall, corral or on the trail. Sometimes I'll be riding with people who see me do a short circle around a manure pile that my horse just dropped and sometimes I get asked why? The reason I do this is that you can get an idea on the health of horse or maybe get a lead on emerging problems by evaluating their manure.

I'm not only looking at what the manure looks like, but how many piles that horse will drop in a given day, and each horse is different. My quarterhorses and grade horses will drop 9 to 12 piles a day, while my Mustang only drops 6 to 7 piles a day.  Any quantity much different and that horse bears watching just a little more closely. 

Each horse's normal manure will look different. Some horses normal manure will be flakey and sometimes break apart when hitting the ground; other horses may drop smaller piles with balls more roundish than not; and yet others may drop egg shaped balls. If I put all my horses in one corral I can tell what manure pile belongs to what horse which is helpful on determining if any one horse is dropping significantly less piles than normal, which can be indicative of a looming problem, usually dehydration and subsequent colic.

Normal manure is generally formed manure balls that appear to be a little wet. If they are not glistening with moisture then I would not get worried unless they appear to have a mucous type covering.   After a while you'll know what is normal for that horse and what is not. The picture of manure at right is pretty normal.

Very dry piles can lead you to believe that the horse may be hydrated. Sometimes I'll soak his hay in water for a couple feeding to see if he gets moisture back into his manure. If I have been watching that horse then I see mucous on the manure then I would absolutely call my Vet. 

Manure piles that are somewhat or mostly unformed, like the picture at left, could be a result of sickness or discomfort, from sand or a change of feeds.  The manure in the picture wouldn't spin me up unless it started becoming worse - wetter and less formed.

Runny and unformed manure piles, almost looking like a cow pie, can be indicative of sand in the gut. My Vet tells me that some horses can have as much as 80 lbs of sand in the gut. The horse's system will drive fluid to the gut to help remove it, hence the wet unformed piles. Dehydration becomes a real threat from this.

You can test for sand by collecting some of the manure that hasn't contacted the ground and put it into a quart sized ball jar. I'll put about 3-4 inches of manure in the jar, then fill with water, shake and let it settle for 15-20 minutes. If there is sand in the gut,  it will settle to the bottom of the jar and be visible. The picture at right is manure, like a cow pie, likely caused by too much sand.  And while it is likely feed issues cause digestive problems which you see in the manure, I also think that, in some horses, their manure can show increased stress. 

If sand is present, especially in any quantity, you need to take action. I will never hesitate to call my Vet, but I also try to stop problems before I call her. I use Sand Clear, a pelleted psyllium seed husk supplement, that I add to my horses fortified feed for a five day period every 4 to 5 weeks, and on one horse in particular I usually put him through a 10 day regime of Sand Clear once every 4 - 5 weeks as he seems to take in more sand than the other horses.

I think that some horses, particularly older horses, may benefit from pro-biotics.   I feed pro-bios in paste form, about every six days, to a couple of my horses.  While I think it may be helpful, I just don't know for sure.      

Another thing to look for in your horse's manure piles is bits and pieces of undigested feed. This can be because your horse is not chewing his feed completely enough - maybe a problem that can be fixed with getting his teeth floated.  Again, preventive care in the form of routine dental exams is a good idea.  Have a safe, and healthy journey.