Horse more reactive on supplements?

So my young gelding is a reactive type…but generally okay reactive (as in a bit hot, will spook some, but rideable, sweet, and gets it together once he has a chance to work/settle).

For the past year he has been on MVP Mag 5000 and SmartPak B1 supplement along with U-Gard. No major issues - very good through the summer…a bit hotter/spookier on windy days or when the farm is busier…but he’s 4 so nothing out of the ordinary for a hotter/sensitive youngster.

I reevaluated supplements about a month ago…so I switched him to GUT by Uckele thinking it had a better overall profile for GI support. Then about 2 weeks later I switched him from the Mg/B1 separate supplements to SmartCalm Ultra…since it had the same general ingredients and would be more cost effective.

Fast forward…I have a fire breathing dragon on my hands. He is out of his skin spooky and reactive…to the point I almost lost him on the lunge multiple times from having a complete melt down (at nothing on a warmer quiet day). Even in the turnout he just won’t settle and is all over the place (not normal). I gave him an ace tablet the one day…it didn’t even touch him (normally it makes him sleepy enough he’s tripping over his own feet). Stuff he never spooks at has him flagging his tail and bolting across the turnout (not like him). It’s definitely not just weather/cold/less work…and it has been building over the past two weeks to this point.

Has anyone had their horse get super crazy on either supplement? That’s the only thing in his life that has changed. I took him off both supplements 3 days ago (putting him back on the old supps)…he actually seemed a tiny bit better this morning. Going to give him a week or 2 to “detox” and see what I have. I had one mare that did this if she was on MSM, but these supplements didn’t seem to have anything in them that would trigger such as major personality change!

MSM is the only supplement I’ve ever seen do that. I did have one act like that when he was fed something he was allergic to, so anything is possible.

I use GUT on my fairly reactive but sweet gelding with zero issues. Switched him to it this spring from SmartGut Ultra and he’s more settled than he was last winter at this time. (Not saying the supplement is doing that but he’s certainly not more reactive.)

No experience with the other.

Have there been any other changes to feed/turnout/herd dynamics?

The only “extra” ingredients in the SmartCalm Ultra would appear to be the taurine and tryptophan. It’s possible (?) that the horse could be allergic to one (or both) of them, or maybe to the alfalfa base.

The only way to tell really if he’s reacting to the supplement is to switch him back to what he was getting previously and see if the behavior reverts to what it was.

If the behavior doesn’t revert, then there’s something else going on.

Take out everything but hay salt and water for 2 weeks. Then add one thing back in. Keep a detailed journal of feed and activity.

This is the time of year horses get less movement overall and get sproingy regardless of feed.


That’s unusual. And rather unpleasant for both of you. Hope you get it sorted!

Not to a supplement but I had a horse that got that way on alfalfa. BO got some nice mixed grass/alfalfa hay and his brain fell out! Not just excess protein as we had cut his grain. Tried once more with similar results so he was banned from alfalfa as something in it really caused him to react. I don’t know, however, if the little bit used as a base for a supplement could cause the same issue.

1 Like

No other changes to his routine/feed/etc. - only change has been the supplements. I actually cut back his grain this week thinking that might be the issue, but that has done nothing (and he’s not on a lot anyway). I think the MVP also has an alfalfa base, so probably not that since he had been on the MVP Mg since last year. Same turnout, same buddies (and they are all acting the same), same feed/hay, same routine (he lives at home, so I know there is nothing strange happening in his environment).

Scribbler - at first I was assuming that it was the weather plus less work and baby horse sillies…but now his reactions are so extreme there seems like there has to be another explanation (I got him as a late yearling so we’ve been through a few winters). The extra spookiness has built up over the past two weeks to the point of being explosive…and it’s not a riding issue because he’s acting nutty out in the field. The one day I opened up the gate to let him go into the grassier part of the field (since he was banging the front gate and being very unsettled while all the other horses were chilling)…this is a horse governed by food and normally the minute that gate opens he is locked into grazing no matter what is going on. He galloped in and out and then didn’t even go graze for another 30 minutes…when he did he would keep spooking/crow hopping at random.

Fingers crossed stopping the supplements does something! Not sure what else could be the cause.

Unfortunately, you could just be stuck with the winter horse stupids. Mine was his perfectly normal chill self the winter of his 3-coming-4 year, but 4-coming-5 he was a little wild and now this year at 5-coming-6… He’s a tiny red fire breathing dragon. Extra work seems to help, but he’s still on high alert and at times I’m flying a kite.

Hopefully for you it’s just one of the new supplements! I’ll keep my fingers crossed :grin:

That’s strange for sure. I actually started my gelding on SmartCalm Ultra last spring because he was becoming increasingly reactive and anxious (and is usually pretty mellow…but new barn, new lifestyle, etc. so…) It has helped him tremendously and I keep him on it because he has some symptoms of magnesium deficiency (tight back mostly), so I figure it can’t hurt (vet/chiro suggested mag for him).

That said. He hates the way the supplement tastes. He acted like I was trying to poison him when I first tested it out and just hand fed it to him. Made a face, spit it out, then whenever I offered it to him again he’d just make the “yuck” face (like he was spitting it out but hadn’t eaten any).

He eats it when it’s in his feed with his other supplements. His feed is wet down and everything is a big mash together, so separating it out is impossible and he loves to eat, so it get eaten.

It’s just something to think about. Could your guy be avoiding it? Spitting it out?

If that’s not it, like others have said, I’d just strip the supplements completely and see if he goes back to normal. It shouldn’t take too long. If he does, add each supplement back separately and see how he does. You should be able to figure out which one is the culprit.

If he doesn’t go back to normal with the supplements taken away, maybe start thinking about ulcers or some other type of pain that could be making him more reactive than normal. I believe that when a horse feels vulnerable his flight instinct ramps up a lot. This was true with my guy when his back started giving him a lot of problems due to bad saddle fit. He went from a horse that I could ride on the buckle all around the farm on a cold, windy day to one that was on the verge of spinning and running away over everything, even on a perfectly warm, sunny, calm day. Things he’d seen a million times and ignored were suddenly so threatening to him that he’d panic and try to run away. Almost backed us both into a ditch over some water tanks that he’d walked by every ride for the past year.

Good luck to you. I hope it’s as simple as the supplements. That’s an easy fix.

1 Like

Had one act like this with tryptophan.

@Heinz_57 the thought did cross my mind we are entering the young horse stage of being fit, strong and still a baby brain! But the fact that he’s been so out of sorts on the ground and in turnout makes me want to give him the benefit of the doubt for now. I hope it’s not that - he’s nearly 18h and super athletic…and a red head!

@RhythmNCruise - he’s not spitting it out…my guy would eat it straight out of my hand (there is not much he turns down!)…but he also gets a little bit of beet pulp with some TC senior and I wet it all down, so he gets it all…and he makes sure to clean every morsel he drops on the floor.

I did a trial of 4-5 days of a full tube of Ulcergard each day (since in the past I’ve always seen improvement after dose 3 with many different horses)…he got worse during this time so I don’t think that is the issue. I did that since I’ve had horses in the past get that reactive with ulcers…always saw near immediate improvement with UG…but no change with him. Saddle fit could be an issue as he’s changed shape a bit recently…but what he is in is a pretty decent fit…and the issues are not just riding - they are going on lunging (no saddle), in the barn, and in the turnout with no one near him.

@iJump - can you share more?? How did you figure that out and what was the behavior/how long on the tryptophan when it started? When I look at the 1 or 2 star reviews on SmartCalm Ultra, I do see a few other people mention a similar issue of horses getting super reactive and hyper…so maybe the supplement is the issue.

@Critter - my guy’s issues were showing up all over the place too. I had an epic thread or two on here about him and his insanity back in the spring/summer. He was terrified of the barn all of a sudden. A mad man in the round pen (no tack on at all), and was okay in the pasture, but a bit prone to fretting about his buddies and running more than usual. He never complained when ridden, but was much more forward (which I thought was a good thing at first…nope), and much more reactive to the world around him.

He also palpated sore on his back though, so, that took some of the guesswork out for me. My best guess was that when he’d start to react to something and spook, his back would go into spasms (the vet/chiro confirmed that his back was in spasms when I finally got her to look at him…she suggested the mag). The pain from the back spasms just made his anxiety and spooking that much worse. There were times when you could physically see his back get so tense and tight that he’d almost lock up completely.

It was such a huge difference from his normal behavior that I knew something was terribly wrong. I raised him from a yearling (he’s 12 now) and did all of his breaking and training myself. I know him as well as you can know a horse, and this was not my horse. He’s very honest, and he was telling me something was wrong.

I wish you the best of luck. I think you’re wise to investigate. Wouldn’t it be easier if they could talk?

L- tryptophan to be more specific. Trial and error really. My experience is with the following…

Perfect Prep is a magnesium calming supplement, and Good as Gold is L-tryptophan. The Good as Gold always had a complete opposite effect on this horse, to an insane degree.

I had a horse who was definitely LESS calm on SmartPak’s Ultra Calm supplement. When I tried it, it was the only change I made to his diet at that time so it was pretty clear to me that it was the cause.

I’ve seen few get like this when on anything with L-Tryptophan.

I’d discontinue that supplement first and see what you get in a week or so. If you don’t see a difference, discontinue the second supplement and see what happens. If nothing changes after that, then look to other causes.

Whenever you change something and get a different horse, I always start by removing whatever I changed most recently and work my way back, but you have to make one change at a time or you won’t know what worked and what didn’t.

Thanks everyone - I did take him off the Smart Calm and GUT and reverted everything back to his old diet/supplements. He was much better in a few days…but still not himself.

Yesterday I had my vet out (as there have been some other odd behaviors)…she thinks he may be a bit neurologic. We took some lunging video (he is hypermetric, but not ataxic) and has a bizarre head flick/front leg strike that seems to be reflexive…not just a feel good baby horse move…it is becoming more pronounced and more frequent (and is not related to being under saddle). Sent the video up the sports med vet at Penn who knows him and me…she did not think we are crazy. She’s already organizing a schedule for him to come up with a neuro consult, plus blocking out time for a potential myelogram and some other diagnostic testing. Both vets are worried about Wobblers or EMD. I am a bit numb and trying not to go down that mental rabbit hole yet. My goal is to get him diagnosed properly and go from there. He is a stunning, amazing horse and super sweet.

Good on you for getting to the bottom of this! I will keep my fingers crossed for a good outcome. One less severe thought that comes to mind, which I’m sure your vets will consider, is headshakers. We had a four year old import who started with a nose twitch and a front leg motion towards the nose that seemed odd. It evolved over a year into a more traditional headshaking, but was completely cured with a nose net.

I had also wondered about the headshaking/trigeminal neuralgia as the past few weeks he was suddenly trying to stop and rub his nose on his leg when under saddle. I didn’t let him get into the habit, but he kept randomly trying. No change to tack/bit, mouth looks fine. That was one of the odd behaviors. But I am not sure that would cause the sudden explosive spooks that land us halfway across the arena with no warning (like he was given an electric shock). He’s always given me a fair warning of big spooks, and little ones were just a scooch forward or side step. Through summer I didn’t even need to lunge and he hardly spooked at all. The massive spooks (or bucking explosions) happen on the lunge for no reason as well (luckily no bucking under saddle - just spooks)…and lunging longer has no effect. The last farrier visit he was having trouble balancing, especially for his shoes behind - when we gave him some hip support he was much better. And that’s something he’s always been good about…and he wasn’t being naughty, he was having trouble standing on one leg. Initially I thought some soreness in his stifles, since that was the initial lameness issue we treated him for in spring. He also stepped on himself while riding, hard enough to rip his front shoe off (just trotting along and had a major trip…when I got off his shoe was yanked half off). Lots of little odd things that by themself don’t indicate much, but are starting to show a pattern. He is also 18h and just over 1300# as a 4yo.

Interestingly, one of the horses who got especially loopy on tryptophan was my TB who was later diagnosed with chronic EPM.

One of the earliest signs was that he was having trouble balancing, especially behind, for the farrier and at first, the hip support seemed to help. Eventually, it progressed to him needing to be aced for the farrier as he was so anxious about it.

He too was strange behind and had odd hind leg spastic type movements and eventually progressed to hind end weakness that made him appear lame. His anxiety and panic levels reached very high levels and it got to the point that he was dangerous to handle on the ground, as he would basically check out mentally in random bouts of blind panic and have seemingly no regard for handlers or other horses in these episodes.

We did not immediately go to EPM as it is relatively uncommon in my area - please, if you are doing neuro tests, don’t discount EPM. I wish I had insisted on the test much sooner for my horse.