Fecal Water Syndrome/Stemmy Hay/Laminitis Risk

My 5 YO fjord gelding has had summertime fecal water syndrome now for the two summers I’ve had him. It’s not awful, but it’s definitely a pain and a mess. It seems to start up around mid summer; July or so. It tapers off around October or so. My hope is to try and get ahead of it this year. The best thing I can come up with is that’s around the time we run out of the previous years hay and the new hay is cut. My barn has several hay fields that supply us all so it is very consistent from that angle and makes for easy testing.

In talking to my vet, he said some horses can suffer from FWS due to stemmier hay. My gelding has always gotten first cut as his weight needs to be managed. My vet did say that sometimes second cutting may not be any worse than first and is softer, but you have to test to know. Would newly cut hay be any harsher on their stomachs?

I got results from past years (I’ve been told the values don’t vary that much year to year); the one on the left is first cutting and the one in the right is second. I’m not seeing any values for starch/sugar/NSC values…Im not very familiar with interpretation, am I missing something?

The only other thing I can think of is something starts growing in the pasture that time of year that sets it’s off.

Looks like sugar/starch wasn’t tested on that batch. I usually get 601 from equi-analytical done when I have it tested.

FWIW, our barn feeds only 2nd cutting orchard and it’s never been 10 percent NSC. I’ve had it tested several times in the past.


Yeah they didn’t test ESC/WSC/starch.

Lots of 2nd cutting Orchardgrass tests fantastic for IR horses. Some test awful for them. Lots of OG on the east coast has tested great for metabolic horses.

Of these 2, the 2nd isn’t what I’d feed an easy keeper due the higher calories. But without the esc/wsc/starch you can’t know if it’s safe for an IR horse.

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My new young guy struggled with FWS terribly this winter, to the point everything was water unless he was on metronidazole. Tried everything I could find on the search here, no luck (ulcer meds, soy free, fecal, blood panel, every probiotic…)

Finally ran an allergy panel that lit up like a Christmas tree. Off the charts allergic to flax, oats, mildly allergic to fescue, some grass hays, bunch of other stuff. But the flax supplement the barn was giving everyone plus oats in the grain were destroying him. We are 8 weeks out and 99.9% firm, the tiny bit of occasional liquid I’ll attribute to the fescue field he’s on but we can live with it.

So worth a shot if you can try that!


@rubygirl1968 @JB thanks for taking a look, that’s what it seemed to me but I wasn’t sure if there was anything else there that pointed towards anything. I’ll have that run on both cuttings we have now and see what things look like.

@Sancudo I’ll look into this, that would be good to know either way and the vet is coming out next week for spring shots. Is it a blood test?

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My coming 28 yr old TWH started suffering from FWS two years ago in mid summer - when plant chemistry starts to change in his 19 acre pasture.

It clears up when the spring grass comes on.

He was under control with the herbal compound “concentrated rheumannia (sp)” when his long time pasture mate colicked and passed away. The FWS returned with a vengeance but with a solid return of spring grass he is much better and off the herbs.

I say this because my holistic vet, who had a chemistry major before entering vet school) feels my 27+ year olds FWS issue is linked to weakened adrenal gland.

There seems to be a surge of threads & posts on FWS in the last two years but there doesn’t seem to be a lot of credible studies on the issue. I read this forum because it is where I learn about Health issues from credible folks. It would be great if there was funding available for the biochemists to study this subject thru at least two complete cycles of the four seasons​:+1::+1:

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Yes, blood test!

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my horse gets this if he eats anything Alfalfa - hay, mixed hay, or cubes. It started maybe 4-5 years or so and took a while to figure out what the cause was.

For real allergy testing you really want the intradermal test. Blood testing is too unreliable in horses

Also, the usual place people are getting blood testing done, is almost across the board showing very high reactions to flax this year. As in, nutritionists and the like have taken notice and see it as very odd, to the point they are questioning whether something is wrong with the equipment interpreting the results.


The weather got hot hot this week and we have butt water again. It’s easy enough to rinse off but I wish it would go away so bad. It can’t be comfortable for him and it’s pretty unsightly.

This is the time of the year it starts! I have that data point. I’ve had him on chia since we moved to the new barn at the end of April and no problems until now. The new barn doesn’t have consistent hay, and up until now the FWS hasn’t been an issue. The temps soared this week and it started up. It’s cooler today and for the next couple days so I’m really curious to see if it drys up any.

I have some Platinum Performance Platinum Balance on the way to try next; people on the FWS Facebook group seem to have a decent success rate with is. Chia is apparently not a help for us.

It’s so weird because so many people in that group have it worse in the winter when the horses are on more hay and less grass. We have ZERO problems in the winter and are basically on hay year round with the exception of the tiny bit of grass that makes it up in the dry lot.


Have you tried Bio-sponge? It might help until you get him sorted. I have a mini that gets watery, mostly during late summer. Bio-sponge sets him right. I can give it a few days until he clears up, then 1/2 dose for awhile maintains him.


A cheap and simple addition is psyllium. It’s not guaranteed, but it’s helped FFWS in enough horses that I don’t discount its potential.

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My 28-year-old gelding used to get fecal water occasionally, usually with a change in hay. Not knowing what it was I used to call it juicy hay. It didn’t last long. A few horses in this barn have it. Last summer my guy got the heavy-duty version, and it wasn’t fun. Both sides of his butt were saturated, and it travelled down the inside of both legs. It also found its way down the crack to the insides of his thighs. It squirted out his anus when he wasn’t pooping. I had to clean him thoroughly every day - something i did not want to continue into a Maine winter. If you goggled fecal water what you usually got was a couple of sentences in a paragraph about leaky gut. (1) They don’t know what causes it and (2) they don’t know how to get rid of it.

I found a bit of information online, Dr Kellon being one source. I’ve been getting my supplements from HorseTech for many years so I contacted Rod, the owner. He didn’t find much more. I did see psyllium mentioned for leaky gut. Fecal water sounds like a possible gut health problem. I tried HorseTech’s product for sand colic. SandTrap is basically psyllium and probiotics and it is ground up not pelleted. Barn staff would be feeding it so I settled on small dose – 1/2 cup in a big plastic “glass” from Walmart. They fill the glass with water and let it sit for a few minutes. Stir it up, then add it to his soaked grain and supplements with more water and more stirring.

(Anecdotally) it seems to work. Not a quick fix but he is getting a small dose of psyllium. No changes in his diet. There was less brown yukky water on his butt. Missing a day cleaning up wasn’t a problem. It didn’t disappear 100% but it was usually dried out so I could curry and then clean. My amazing horse got to enjoying it when I scrubbed his thighs. He spreads his legs far enough apart to make it easier.

There is much more online recently about fecal water. Some yeasts and esoteric additives create by-products when they breakdown. A few seem to help gut health and fecal water. HorseTech has received more calls recently about fecal water. Rod is working on a special-order product. My horse has a clean, dry butt with an occasional squirt. Stress and ingredients in their diet can contribute to fecal water. My plan is to add this to his regular supplements to help maintain his gut health.

Any thoughts on what could impact gut health in the summer time? Is stress from the heat enough? He is good about water and salt, and I do a small amount of soaked hay cubes before/after rides to get a little more water in his system esp when it’s hot.

That seems to be the common denominator; when I got there today he had a little, but significantly less than the last couple hotter days. It got down in the 50’s overnight and we’re highs in the 60’s today. On bad days, he’s very close to the worse that you describe. Next bad bout I’ll get some photos.

I originally thought hay at first, hands down. At our old barn, they cut their own hay from the same fields each year, but this would be the time to feed to new stuff and it would start up. Now with him having hay from prob 6 different places/qualities at our new barn with no issues until the heat, Im not so sure anymore. It, so far, has been entirely seasonal with summer.

I’ll be looking into psyllium and the bio sponge as well.

Heat stress alone could cause this, for sure. He’s a heavily built guy, pretty much done growing, and that’s when “things” seem to start popping up. The growth of youth has a lot going for it LOL

@JB very good to know, I’m going to run under the assumption this is definitely a big factor. He started this when I got him in July 2020 and thought it was just the change from moving from his old home to ours.

Poor guy. He is more and more like me. Thankfully THAT isn’t one of my issues, it i don’t tolerate the heat and sun well. Thankfully at our new barn, he is back to going out overnight, is in a cooler barn that is more protected from the sun, and has a heavy duty fan. Even in the 90’s he wasnt sweating in his stall so that was great to see.

Would adding some kind of electrolyte possibly help?

Very interesting topic! My boy has been suffering with this since last fall. I started him on a probiotic near the end of winter and thought that it was working as he isn’t passing much liquid any more. However, after reading this thread I wonder if it’s the hay over the winter (he’s on pasture now) that is the culprit.

This is interesting. Friend of mine just had her horse tested. A few things sort of high-ish but not alarming. Flax numbers off the charts in comparison.

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While I don’t have a horse that gets that particular issue, I wouldn’t be surprised if high heat is the culprit. Especially when it stays over 70 at night, it’s just hard on the animals.

My old TB came to me with soft poop issues. I think probios made the most difference. Some would work well for a bit and then he’d be back to soft poop. I have had the best result switching him to TCS Gold that has a good gut support package. He will still occasionally get mildly soft poop when getting a new hay. I have him on electrolytes this summer. It hasn’t upset his stomach at all. And I do think it helps him feel less heat stressed. Might be worth a try for your boy.

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Is there a particular brand/type of electrolytes you recommend?