Anhidrosis in Horses: Rio Doesn’t Sweat

Anhidrosis in horses can be a real betch. My family used to have a pony with it, and she spent the summers in a large stall (that was open to the pasture) with a misting system and multiple large industrial fans. Unfortunately, I am facing the fact that Rio also has a real problem with sweating.


anhidrosis in horses hunky hanoverian
This is me, for the rest of the summer


Last summer in Texas was fine. Hot? Yes. But it didn’t really get stupid hot until mid July, and even then I avoided the worst of it by riding in the evening at about 7:30 or so. I honestly kept thinking last summer how it wasn’t that bad. Really.


This summer? I am already dying. Rio is dying. We are are dying together. It was first noticed last summer that Rio doesn’t sweat very well, but it honestly never became a huge issue. Like I mentioned, it wasn’t too hot in Dallas for most of the summer, and I avoided the worst of it by riding as the sun was well on it’s way down. We put him on One AC and called it good.

anhidrosis in horses hunky hanoverian
I give this supplement 1 out of 5 stars. Or zero, if that’s allowed.


I’m under the impression that One AC works for some horses, but it doesn’t do shit for Rio. He’s been on it since the beginning of April, and is NOT sweating. It’s bad. It’s been so friggin hot lately that I’ve ended up having to cut some lessons short, or barely hack for 15 minutes, for fear of over-heating him.


A bucket of water was placed ringside with a rag for Saturday lessons (I rode at 10) and Rio was repeatedly wiped down, but it didn’t seem to make a difference. Any time we weren’t going (group lesson) we were chilling in the one shady spot in the ring (thank God for the ringside tree). There is also a large water trough in the ring that is always kept filled with fresh water, but Rio will NOT drink from it. I mentioned to my trainer that we might want to hose him off BEFORE our lesson, and she agreed that was a good idea, so I will try that next time.


anhidrosis in horses hunky hanoverian
Missing when you could be outside in the sunlight and not soaking wet with burning sweat in your eyes


Of course riding earlier would be ideal, but her schedule hasn’t allowed it yet. At this point though, I am going to either have to lesson earlier (like 8 am) or not lesson at all when the temp is in the upper 90’s, at least until we get Rio’s sweating figured out.


So what’s the plan? The vet at Bay Yard also practices some eastern medicine. He does chiro, acupuncture, and occasionally uses various herbs alongside or sometimes in place of traditional meds depending on the situation. Although I am somewhat skeptical of eastern medicine, I also don’t claim to know it all (far from it LOL) and he has apparently had great success with some other anhidrosis horses at the barn using some Chinese herbs. Since the One AC is obviously doing nothing for Rio, we are going to try the herbs. They are more then triple the cost of One AC per month (of course, I obviously hate money), but the price will certainly be worth it if they get him sweating again.


anhidrosis in horses hunky hanoverian


Does this sound like snake oil voodoo magic? Maybe. BUT, I trust the people at my barn, and they said they have seen it work first hand, so I’m willing to give it a go. Do I worry about side effects to unregulated herbs, such as on the kidneys and liver? A little. I work in human medicine after all, and have heard some horror stories of damage being done by “natural herbs”. But, I also have to weigh the risk of the very real threat of over-heating. It’s only early June after all, we have 3-4 months of heat ahead of us.


Anyone else struggled with anhidrosis in horses? What did you do? What worked, and what didn’t? Do you give your horses Gatorade/Powerade? Rio already gets electrolytes in his grain, but I’m wondering if there is anything else I can do to help him out.

You may also like


  1. Once they stop sweating it’s pretty hard to get them to start again. The key, from what I’ve seen and experienced, is starting them on whatever supplement/treatment in mid-spring. BUT… I have seen a few that randomly decide to start sweating again. I think it’s a really individual thing, because for some One AC works, for others TrueSweat works, for others beer works, for some the Equiwinner patch works, for some acupuncture works… but I’ve never seen one thing that consistently works for every horse. It’s a really frustrating issue. Hope you find something that helps!

  2. Kelly! I’m so sorry to hear this news about Rio. I give all my horses (my own and the lesson horses/training horses) Gatorade powder or mix it up with a gallon or two and let them drink it. I also keep copious amounts of rubbing alcohol on hand during the summer. If you pour it down their spine it helps evaporate the heat and cools the horses internally. I would take one ring side to help with your sponge baths. (Obviously not where the saddle sits but down the mane and behind the saddle to the tail)

    If Rio does get to the point where you fear he’s over heating you can use the mist and scrape method along with the alcohol down the spine to get his body temp down a little quicker.

    I know you’re trying to get on the trainers earlier schedule which would help the most!

    Let me know what you find works or at least helps.

    1. Thank you Eryn- I had forgotten about using alcohol. I used to mix it with water for post XC schooling/runs, that is a great idea. I think I am also going to try to get him to drink the Gatorade- do you buy a low sugar version or is the sugar ok for them?

      Thank you for your concern and support!

      1. Hey Kelly,

        Sorry for the delay. I use the full sugar version as we aren’t certain of the negative effects of low sugar foods and beverages that were not created specifically for horses. I have heard sugar substitutes can kill dogs so I veer away from low sugar just for safety sake! How did the alcohol help?

  3. Ditto what Amanda said. I’ve had friends have good luck with Guinness. Thankfully (so far) none of mine have been no-sweaters.

  4. Ugh, I am so sorry — this a frustrating situation I have had first hand experience with. I had a little black jumper that like to stop sweating in the summer (no joke, first cold front that would come through, he’d start sweating again). I was in college so my schedule was flexible. He got on One AC and stayed on it. I would go out in the afternoons to repeatedly hose him down with cold water, and I only rode him after the sun went down, after another hose down. That all kind of helped, but riding during the day in the summer was out of the question for him and we didn’t jump or try to show him then.

    I have heard anecdotal evidence about the herbal mixes and that they seem to work very well. I hope you find some relief for Rio!

  5. Oh no, poor Rio must be miserable 🙁 Sorry/thankfully I don’t have any advice because I haven’t dealt with it.
    Cupid sweats like a pig (misnomer since pigs don’t actually sweat right?) but he hates electrolytes! He won’t drink it in water, but will barely tolerate it in his grain shuffling everything around with his nose trying to shake it out but eventually giving in and eating it. Maybe I should try Gatorade instead of something horse-specific!

  6. Ugh, been there. Lucy doesn’t sweat either.
    When we were showing, she was on beer and it did work moderately well for her. Otherwise, I swear by rubbing alcohol to cool them off. She refused to drink Gatorade or water with electrolytes in it, but I want to say we found some that we added to grain that she’d eat. It’s been ten years though since we retired her and stopped worrying about it.
    I have a vet on my staff who does a lot of the herbal medicine and it’s pretty amazing stuff – I wouldn’t be too worried about kidneys/liver if it’s being done by a DVM – there’s a lot of info out there in their world about it and it’s becoming more and more popular almost by the day.

    1. That’s really encouraging to hear about the herbal medicine! I didn’t really realize it’s prevalence in veterinary medicine. I’m very curious to see how it helps!

      What water to alcohol ratio do you use for sponging off a hot horse?

  7. Anhydrosis (which I am incapable of spelling) is super stressful. Especially in a climate like yours. I mentioned on FB already, but did have success with Jamp feeding him Guinness. Doesn’t work for everyone, but it did help him. And last year, he sweat on his own oddly enough. He’s only handwalking right now, so not sure where he is this year. I can’t give him beer anymore because of the laminitis. So hopefully it will not be an issue.
    I haven’t tried the Chinese herbs for anhydrosis, but I used one for hind end that I thought made a real difference for Jamp. So they might be worth a shot!

  8. So Libby actually has had problems sweating these past two years. Last year, nothing helped. I did One AC at the triple dose, tried MegaSweat, and also started her on double electrolytes. I ended up needing to use Ventipulman to make her sweat, and after that it like reset her system. When she wasn’t sweating at all, I would take her in from riding, sponge her down with alcohol and water, and park her in shade to try to allow her to catch up. I’d also give her like 3 cc of ventipumlan, and add from there if she needed it. Not sure if he’s on Depo, but I’ve heard that that could mess with their sweating patterns.

    This year I started her on Let-M-Sweat early, and noticed around April that she wasn’t sweating well enough already, promptly switched her to the triple dose of One AC, and did Acupuncture. Thankfully, she has started sweating normally again. Thank god, because I think this is going to be one HOT summer for us down here in FL.

    I should also add that she has three fans on her at all times, and she goes out at night. I can’t do the Guinness, because of the sugar, and honestly the amount of beer per lb to really make a difference for her is too much.

  9. i am lucky Remus sweats tons (take a look at that photo at the header of my blog, sure some of that water is from the water jump the rest is his (and my!) sweat LOLOL

    I hope you figure Rio out. Poor thing. I would give anything a try! Good luck and let us know what works (if it is voodoo or whatever) LOL Love the Hocus Pocus gif 😉

  10. My mare had this problem when I first brought her to Texas from Ohio. We did the acupuncture treatment followed by 1 cycle of the herbs and so far she hasn’t had a sweating problem since! Multiple horses at my barn go through the same process every year and have no problems sweating through out the summer (acupuncture followed by 1 round of herbs). We also do 1 very dark beer a day mixed with their grain which seems to help.

Leave a Reply

Your email address will not be published. Required fields are marked *