By Kim Hallin
If your horse struggles with either hipohydrosis (partial inability to sweat) or anhidrosis (complete inability to sweat), the summer months can be a nightmare. I’ve been through it myself – with two different horses.
My Arabian gelding (Shoki) developed hipohydrosis in 2005 after being put on a combination of medications to treat his severe gnat allergies and sweet itch. In Shoki’s case, the solution was as simple as taking the antihistamine out of his treatment protocol. His hipohydrosis was short-lived; he is now 29 years old (pictured left and looking fabulous on Cool Stance!) and, thankfully, has never had a recurrence. In Shoki’s case it was an antihistamine and a steroid being given in combination (at the recommendation of my vet) that left his body unable to sweat properly.
My Quarter Horse mare (Puck) is a different story. She developed sudden onset anhidrosis when she was nursing her foal during the record-breaking South Carolina heat wave in the summer of 2007. Puck went on to endure three long years of complete anhidrosis, but in the end her body was able to make a full recovery. The key, for her, was in cleaning up her diet.
There are many theories (but it seems no proven answers) in regard to what causes anhidrosis. My guess is that there are a variety of factors that, in combination with the unique biologic and microbial makeup of certain horses, creates sufficient internal havoc to induce full or partial anhidrosis. In Puck’s case, the condition appears to have been metabolically-induced. I believe her risk factors escalated after an intensive 6-month round of oral and topical antibiotic/antifungal medications that were administered to treat a fungal eye infection. This treatment protocol ended about one year before I bred her but, at the time, I did not know it was important to rebuild a healthy microbial population/environment in her gut once the eye was healed and medications discontinued.
So, unbeknownst to me, Puck (pictured here just a few days after giving birth to her foal) went into her pregnancy with digestive and immune systems that were both significantly compromised. Thankfully, she still had a successful pregnancy with only minor complications, and gave birth to a healthy filly. Being a first-and-only-time breeder, I did what most novices do: I trusted the nutritional advice I was given by my veterinarian. I knew going into the pregnancy that Puck was an extremely “easy keeper”, but so did my vet. So it never occurred to me to question the recommended protocol; I just followed the recommendations and in so doing, I loaded Puck up on high-NSC (sugar/starch) feed. And, I even added alfalfa hay to her diet! Puck looked phenomenal throughout her pregnancy and even during most of the time that she was nursing her foal (hormones will do that!). So, unfortunately, I still had no immediate reason to question the feeding protocol or Puck’s overall health.
But, what I didn’t know then is that high sugar/starch feeds put incredible stress on the equine digestive tract and that the digestion of legume hay creates significant added heat in the gut (which then gets dispersed throughout the body). Combine all of that with record-breaking heat/humidity… and apparently I had the perfect recipe for an anhidrotic crisis.
One day when I went outside to visit with the horses, I found Puck completely drenched and sweating excessively. Every inch of her body was already soaked and yet the sweat kept (literally) pouring off her. I’d never seen anything like it and I rushed to hose her down and try to cool her off. After she dried she seemed fine… until the next day when it happened all over again. Then, as suddenly as the excessive sweating had appeared, it turned off like a faucet.
For the next three years, I never saw a normal drop of sweat on Puck again. During that scary and challenging time I tried just about every suggestion I heard about (Guinness beer, yeast, electrolytes, herbal supplements, you name it) to prompt her sweat glands to reactivate. A supplement called One AC, which was recommended by my vet, turned out to be the one and only treatment I tried during that period that spurred even the smallest amount of spotty, uneven dampness… but it wasn’t true sweating and it didn’t produce nearly enough moisture to provide Puck any cooling relief.
By the next summer, not only had Puck failed to regain the ability to sweat but her coat looked dull and she even started developing bald spots. I was at my wits end until I discovered Cool Stance in the fall of 2009. After about 6 months on Cool Stance (and no other treatments), Puck started to sweat again. It was not a complete reversal in the beginning but by the following summer, she was sweating normally! We’ve now been through seven more summers and she’s still doing great. This spring she is already sweating normally.
Below are three more “anhidrosis stories” I’ve learned about. These owners agreed to share them in case any of the information is helpful to others:
Lori and Wilson
Lori first noticed that Wilson (then a 9 year old OTTB) was overheating and having trouble sweating during the same SC heat wave in the summer of 2007. But, she says, it didn’t really get bad for him until a couple of years later. Wilson’s anhidrosis is unusual in that he actually sweats somewhat normally until around mid-July when the humidity starts staying high even throughout the night. At that point, Wilson’s sweating system shuts down “like clock-work” until sometime in September when the humidity starts dropping at night again, then his sweating kicks back in.
To the left you can see how Wilson looked at the worst point of his anhidrosis. Initially Lori tried ACTH injections. Then she tried detoxing Wilson’s system using the Vita Royal feed program. Lori spent thousands of dollars on detoxing products only to have Wilson come close to “checking out”. After getting through that episode (where they literally had to keep cold wet towels on him for several days) she transitioned to a protocol of spirulina plus a combo of One AC and Guinness beer – all with little success.
“At some point around then I switched Wilson to Cool Stance. For the first year or so I also had him on a triple dose of One AC, Chinese herbs, electrolytes and beer. Still, the results were not great. But, now that Wilson has been on Cool Stance for a few years, I’ve been able to really back down on the other treatments and last summer we were able to manage his anhidrosis with just Sweatwerks and Cool Stance! I still throw in some Guinness at times just to hit him with it.”
Loris says that despite the fact that the past two summers have been atrocious heat-wise they have also been his best – at least in many years. As you can see here, Wilson looks fabulous! He still gets hosed down during the day as needed and he has a fan in his run-in. “I really do believe Cool Stance has been a big part of his improvement. He’s no longer having the heavy panting that he used to exhibit and his temps are staying down. At times in the past he would hit 103 to 104 degree ranges – very scary! He’s still not sweating normally, but he’s definitely managing his body temps much better. And,” she adds, “Wilson used to blow up with hives if a bug so much as flew past him. Now he rarely (knock on wood) has a reaction to a bug anymore! The only thing I can attribute his improvements to is the Cool Stance because I’ve cut back dramatically on all the other supplements I had been trying.”
Corrie and Harmony
Corrie starts by saying, “Harmony and I are probably a better example of big struggle vs. success with anhidrosis. Still, I am always hopeful that this year we may be better equipped.”
Harmony is “18 years youngish”, and most likely a Haflinger-paint cross (no records). She is an easy-keeper and Corrie struggles with her weight in the summer time when it is not safe to exercise her (due to overheating) and the grass is also green. Harmony has been on Cool Stance for almost a year and a half. Her weight has slowly trimmed up and Corrie says she is going into the spring looking good.
“Over the years I have tried the following, individually and in various combinations, with not much luck: One AC + electrolytes, Sweatwerks, Platinum Refresh, Guinness, acupuncture, and Equiwinner patches. Last year at the end of the summer, we tried the following combination and finally found her some relief: Cool Stance + high point minerals + platinum refresh + excel eq omega oil + forsythia (herb smith) + Guinness + thyroid medication with occasional acupuncture.”
Corrie adds, “I stumbled across a Facebook group that I found helpful: Support for horses with anhidrosis.”
Robin/Hardy and Aries
Robin and Hardy say that battling anhidrosis has really been a challenge for their Friesian, Aries. He was born at their barn in 2007 but he only developed anhidrosis a few years ago – after being on Cool Stance for many years. The fact that Aries’ coat is black could be a factor, but his life also started with an emergency run to NC State for severe diarrhea when he was only two days old. He was diagnosed with a clostridium difficile infection that the vets said could have been picked up in the womb. They nearly lost Aries then but today he is 12 years old (pictured below). Robin and Hardy say they can’t help but wonder if his early infection pre-determined his anhidrosis?
So far they have tried a variety of treatments including beer, Equi-winner patches and Sweatwerks – all at different times without success.
“This year we don’t really know of any other options,” says Robin. “We hope we can manage his anhidrosis with the carport/shelter we had installed in his pasture to keep him out of the heat while he eats hay. We also started him on Mullein tea recently since last year he was diagnosed with heaves as well. Perhaps this will show some positive results for his anhidrosis?”
In addition to Cool Stance, Aries also gets High Point minerals, turmeric and black pepper. The Browns plan to switch him over to Turmericle to see if that has any better overall effect.
Robin said she also just discovered this article about herbs, which might be worth researching for others who are struggling with this very challenging condition: https://www.organicfacts.net/home-remedies/anhidrosis.html