I’m getting to my wit’s end trying to get in front of my 18 year old horse’s chronic issue with loose stools/diarrhea. This horse has never had any health issues at all and has been at the same property for the past 5 years. There were no changes to anything (no changes to hay, grain, supplements, workload, no new horses, etc.) when this started. It was like someone threw a switch in November 2018 and he went from solid, normal poops in the AM to suddenly horrible liquid stools … and a lot of them. Not only that but they were absolutely foul smelling. Since then (~3 months now), it has ever so slightly improved and by “improved” I mean it hasn’t gotten any better than the consistency of a cow pie and it just runs out of him. The smell has slightly improved but it’s not normal and still quite foul. I tried a week’s of Probios first without any success. Then, the vet ran a fecal, bloodwork, and diarrhea panel … nothing turned up to indicate a cause or reason. All normal. Vet checked his teeth and performed his annual dental with nothing remarkable to cause reason for his diarrhea. We did a month of psyllium … no improvements. I took him in and had ultrasounds, X-rays, a belly tap, and a rectal biopsy done and nothing was found other than the ultrasound shows he is moving food through his intestines and colon quicker than should be. Blood work, again, normal. Took him off his grain (Triple Crown Lite) and took him off all hay. Changed him to a complete pelleted food (Stable Mix). He decided he didn’t like that feed at all, came off his feed, and then tried to colic. He went into the emergency clinic and recovered within a day and went on a different pelleted food (Purina Equine Senior). He’s been on that food for a month and still, no improvements. We then started him on steroids (Prednisolone), starting at 22 tablets/day and then a taper down. He got a little firmer stool with the steroids but again, nothing normal, just a firmer cow pie. When we got down to 11 tablets/day, the liquid stools returned so bumped him back up to 18 tablets/day. Still, no improvement after over a week at the higher dose, remained at the liquid like cow pie. I started him on 2 tubes Bio Sponge 3x/day 3 days ago and haven’t seen any changes at all but am going to give it a full 7 days. He gets his food divided up into 4 meals/day, drinks, seems very happy to walk around and graze or run around in the arena and play. In work or not, still the messy stools. Next idea I have in line is metronidazole. I know antibiotics can cause GI upset but at this point, I don’t know what else to do. Outside of that, I’m out of ideas for him and I think my vet might be too. I feel horrible because we have no idea what triggered it and why it’s persisting. No matter what the vet does, directs, or recommends, nothing seems to be helping. If anyone here has any ideas or has experienced this issue, I’d love to hear it. I feel like I’m failing my horse and it’s heartbreaking 
I’ve had horses clear up on Herbs for Horses (Guelph Ontario) probiotics plus YeaSacc. Ten days of probiotics at full or even double strength. I think whatever the trigger, they can poop out all the good gut flora and be unable to regrow it fast enough.
I have a friend that has gone through almost the same thing with a gelding she has. Only she has been fighting the issue for closer to 18 months. She finally ran an allergy panel, cutting out the hays and grains he was allergic to did help but it didn’t fix the problem. What finally has worked is only feeding the horse soaked alfalfa cubes/pellets and literally NOTHING else. Its not ideal but after this long of him having liquid poop living on soaked alfalfa isn’t so bad.
Since switching type of feed hasn’t worked, what about his hay? Can you find a different supplier and/or different type of hay in your area and give that a go? Since forage makes up a large part of a horses diet, just maybe something about your hay is contributing to the loose poops. Even hay from the same supplier can vary from one field to the next, and one growing season to another.
And you’re not failing your horse. Seems you are trying everything you can think of to make him better. 
I thought the same thing and after the attempts with probios and the month of psyllium, the vet ran the ultrasound which showed way too much movement in his intestines and colon. The veterinarian instructed to take him off all hay and his grain a little over a month ago and put him on the complete feed. The thought process being it is easier to digest. Sadly, it hasn’t changed anything.
This is an interesting idea. Your poor friend … 18 months So frustrating. I was wondering if suddenly he developed an allergy? It’s definitely not an ideal diet but the prolonged diarrhea isn’t good either. I’ll ask my vet about that. Thanks for the idea
Thanks for the suggestions! I’ll ask my vet and look into those. Never thought about them not being able to repopulate the good flora fast enough. I just gave up on pro/prebiotics when they didn’t work the first time even though I was dosing it daily.
AH! I missed the part of taking him off all hay.
Same thing with mare at our barn. Wits end. Barn chiro suggested (IIRC) something off with horse pH. First day on baking soda it stopped. Don’t know dose. Something like one Tablespoon then up to three - per feed or day - don’t know. No more diarrhea is result.
The foul smelling manure along with loose manure makes me think hindgut. I’m in the process of going through some hindgut issues with my horse. In working with my vet we tried a 30 + day treatment of Succeed, Equishure and Sucraflate with little success – though I have had success with those products in the past.
I am now on about day 10 of Equivision’s 21 day hindgut program https://strideanimalhealth.com/21-da…ealth-program/
So far so good on that program. His manure has firmed up and his gut sounds are way less rumbly. Not sure what your budget is but you might want to give that a try. They are also very helpful with questions, you may want to give them a call and inquire if the 21 day program is best or the GI Calm for Leaky Gut. The customer service rep I talked to didn’t have the answer to all of my questions and Dr.Bill actually gave me a call to discuss.
We went through something similar with a geriatric QH of ours who we had for the last 15 yrs, never had any digestive issues and was a total airfern… until he wasn’t. He has lived outside 24/7 with a nice run in and TO buddy, round bale, and all he had ever needed to stay in good weight was 1 qt of hay stretcher for the last ~10 years. Suddenly, he dropped a lot of weight, developed liquid stool, when nothing had changed in his diet or management.
We tested for cushings, blood tested, ran lyme snap test, had the vet out to look at his teeth (he had a few missing but seemed appropriate for his age), ran multiple fecals, treated for ulcers, fed several hindgut supplements, switched his food up, tried psylium, probios, etc… pretty much did what you did, minus the belly tap, with no answers.
In the end after lots of diagnostics and no answers, our vet thinks his hindgut was getting irritated because while he is masticating fine, he’s older and his teeth are not perfect. He never quidded or showed signs of having difficulty masticating hay… but… she believed that maybe he was not masticating it 100% and because it was not masticated properly once in his digestive tract, it was irritating his hindgut/intestines.
She told us to take him off of hay completely, put him on soaked alfalfa cubes, senior complete feed soaked (we used TC Senior) , and a high fat extruded pellet (we used Amplify) until he put on decent weight again.
FYI, it took a while for us to see a change when we removed hay. I think it took about a month for his hindgut irritation to settle… but then overnight he was blooming again.
I know you mentioned you did fecals… but one thing I have seen cause unthriftiness unrelated, sometimes, is encysted strongyles - and they don’t show up in fecals to my knowledge (unless that has changed in the last few yrs).
I only have a couple of suggestions --I have a 29 year old OTTB that goes liquid poop every fall when started on hay, so this might not apply to your horse [yes, I’ve tried switching hay, no change]. Secondly, never had this fellow evaluated to the extent you have as he is very old. What I do (based on vet recommendation) : I buy Bio Sponge in 5 gal buckets --it’s a powder, not a paste in that size. Horse gets varied amount in each feeding based on how loose he is (based on how much liquid poop has landed on his hocks). He gets a 1/8 to 1/4 cup of the powder --each feeding --that pretty much clears him up. If I stop the powder, the liquid poop returns --so I’m guessing the Bio Sponge is working for him —but be aware it takes 7-14 days to become effective and I use the powder not the paste (cost consideration and I can control the amount I give). Second thought is more to maintenance of a horse with diarrhea.
Don’t know about you, but I got exhausted trying to keep the old gentleman clean —and wow did he smell bad. His tail turned into a poop-sicle in the freezing weather --one solid mass of frozen poop. [Anthropomorphic, I know] but he’d always been a show horse and seemed “ashamed” of being the stinky horse in the barn. Ultimately, after doing yet another tail wash in -3 weather only to have it immediately freeze again, I found a solution on this BB. At the start of poop season, I wash his tail and put in conditioner. I dry it, then take a leg wrap and wrap his dock (look on YouTube if you need to), flipping a little piece of hair up into the leg wrap to keep it from sliding down his tail. After the tail wrap is on the dock, completely from top to 3 in from the end of the tail bone, I fasten it, and tape it --duct tape --for security. Then I comb out the rest of his tail and do a neat (rather tight) braid the rest of the length to the very end and fasten with a baid-et rubber band or two. My last step is to rub Desitin (you can buy it in large jars) on the area under his tail and along the sides of his butt where the liquid poop might slide down. This prevents the liquid poop from sticking to him. He may hit his hocks (what gray hose hasn’t mastered that skill?) but a quick brush cleans that small area. Everything else --tail and butt stay poop free. I change him about every two weeks or when the tail wrap comes off on it’s own --but it usually stays on. I don’t mind doing this for the old fellow --so much easier than a butt wash in -3 degrees.
Hummm, just wrote a long, thoughtful post that was removed immediately with the word “unapproved . . .” what up?
Second try (summary of the first eloquent post that was unapproved . . . My 29 year old horse has same issue. Never tested like yours. Bio Sponge in 5 gal buckets (a powder) clears him up given in various doses each feeding depending on how much poop is on his hocks. Took a week to see improvement and 14 days to clear up diarrhea. But given EACH feeding and in a powder form 1/8 to 1/4 cup. Oh, my old horse only has liquid poo in the winter --probably hay related, but at his age extensive testing isn’t going to happen.
Last —I got tired of doing a booty-wash in freezing weather and the old guy smelled terrible. I found a solution on this board. At the start of diarrhea season (when he goes on hay) I wash his tail, add conditioner, and wrap his tailbone from dock to 3 inches from the end (flipping up a small piece of hair into the wrap to keep it in place -see YouTube). I put duct tape to stablize wrap. Then I do the rest of the tail in a tight braid to the end, fasten with a rubber band or two. I use Desitin on his Butt Cheeks (buy it in big containers) to keep the poop from irritating under the tail. Now the only poopy part is the hocks, but that seems to bush off easier than washing a tail. I change the tail wrap every week to two weeks.
I had a mare with similar issues for years. I don’t have any great advice as we were never able to resolve her issues. We never improved beyond the cow patty manure though she held her weight (she was in good condition or fat) for years until… she didn’t and it was quickly down hill. I have 3 different vets working with her over the years and tried everything you tried and more. Metronidazole didn’t help (though she went off her feed on that one), biosponge helped in the beginning as did alfalfa. Hindgut treatment did nothing significant. In the end, nothing really worked more than once (short term shocks to her system?). Eventually her body just stopped processing nutrients and everything just went right through her and I made the decision to say goodbye (her shift downhill was quick). She was only 14. There’s a thread on her somewhere… I’m really not helpful here unfortunately. She was a medical mystery to my vets and they all said the only other option they could think of was a trip to New Bolton which might reveal a cause, but likely no additional treatments.
I went through many years of this with my pony gelding Salt. He was named for his very light gray color, so you can imagine what his back legs and tail looked like all the time. My vet suggested a ton of different things for him. The only things that worked for a while were Bio Sponge (a few months) and Pepto Bismol (also a few months, and I had a pink horse because he wouldn’t eat the chewable tablets). Salt was always too fluffy in those years. This started sometime in his teens (I never knew how old he was exactly), maybe six months after I got him, and he was always up to date on worming and teeth.
I’m not sure what prompted my husband to make this change, but he added Purina Strategy and switched Salt’s hay from grass hay to alfalfa. It was like turning off a switch. He never had a problem again. I also never, ever changed his feed for the rest of his life. It became much easier to manage his weight after the changes.
I still don’t know why that particular change worked. I also don’t know if just changing one of those things would have taken care of it. I was surprised that my husband made two changes at once, but at least they were easy to maintain.
Rebecca
I agree that with the foul smelling part, it sounds like hind gut.
I also agree with the suggestions you’ve gotten regarding approaches to making his hind gut healthier (Succeed, Misoprostol, Sucralfate, etc.).
I’ve had horses head into diarrhea territory because they’re unable to chew as well as before, and senior feed has helped in those cases (though you’ve tried that, so may be safe to rule out?).
The other thought I have is a fecal transplant. We did this with a horse I had years ago who we couldn’t seem to make a difference on with probiotics and supps. We took healthy horse poop, mixed it with water (IIRC? It was a long time ago!), and then syringed it into his mouth. That seemed to make the difference. The idea is that you’re taking a healthy gut flora and “transplanting” it into the horse who doesn’t have a healthy gut flora. Same reason some horses eat other horses’ poop.
An article that links to a bunch of other articles about it: https://phylogenomics.blogspot.com/2011/12/transfaunation-and-fecal-transplants.html
And another article that describes how one vet clinic does it (or did it?): http://www.scielo.br/pdf/pvb/v38n8/1678-5150-pvb-38-08-1564.pdf
Never heard of this! It’s worth a shot. Probably the least expensive thing to try too! I’ll ask my vet. Thanks for the suggestion!
I think so too on the hindgut. I was just researching Succeed, Equishure, and Sucraflate last night online. Definitely something to consider trying. Sorry it isn’t proving to be successful for you now but hopeful to hear it has worked in the past … who knows, it might help my horse. Definitely appreciate the suggestions. I’ll give them a call today and inquire as to the 21 day program or the GI Calm for Leaky Gut. Thanks!
Yup, he’s been off all hay and grain now for at least a month and no improvement. Funny you say strongyles … I was just looking at that last night online. I think it still holds true that they don’t show up in fecals. He was wormed with Quest Plus in November after all this started just to see if it would help. Obviously it didn’t. But, that was almost 4 months ago so I’m considering giving him a tube of Quest again. He sure has all the symptoms of sm. strongyles. Really, it’s the only diagnosis that he checks more than a few boxes on.
