Suspected PSSM - diet / management advice appreciated!

[EventingMaff]

Hi All,

After many many many months of exploring young horse NQR-ness (see original post here if you want to catch up on full saga), what I thought was solved may have only been partially solved.

Hind shoes solved a lot of the issues (bucking, sore back) and for a while it seemed strengthening was getting rid of many of the other symptoms seen (switching behind, circumduction of hind leg, slightly dragging toes).

However I suspect she may be PSSM (type 1 or 2 though not sure). Horse has always come out a bit behind the leg and needed a good warm up to limber up, a longer warm up then a 6 year old likely should need. Then when the temps started dropping in the fall, suddenly we started seeing significantly more lead switching behind, lateral stiffness, and circumducting behind - as if her muscles had suddenly stiffened on her and moving fluidly is a lot harder. In reflecting back, we saw this same issue last year: cold weather --> sudden downturn in performance.

Current management:

• Outside 4 PM - 7 AM (~15 hrs) on ~3 acres and many days also gets another 1-3 hours during the day (smaller indiv turnout paddock), but not guaranteed
• Eats 1/2 lb ration balancer with ~8,000 IUI Vit E, Se to balance, MagRestore, DMG
• Lots of access to grass hay (1st cut)

Even if this is PSSM, there’s not much to change - that I’m aware of - in her diet or management as we, through pure blundering, have basically ended up in a PSSM routine anyhow.

My understanding is that oil can be added if extra calories are needed - either because horse is thin (she’s not, she’s super easy keeper but in perfect weight right now) or because horse is “flat” in work (maybe slightly? but she’s been so uncomfortable we haven’t really been working her these past 2-3 weeks)

Is there anything I’m missing on how to better manage the seeming muscle tightness / discomfort she’s in? Or am I potentially facing a world where Nov - March she’s just not going to be able to perform and riding should be focused on movement to clear out the muscles rather than training?

Hoping to submit a hair sample soon but haven’t done it yet.

[Scribbler]

I would do the test. I’m not sure PSSM is weather related.

My big beefy mare will throw all kinds of subtle stiffness, reluctance, odd foot fall patterns, and honestly it’s all in her feet. Getting her trim balanced and boots on her makes a huge difference. Circumstances mean we sometimes go a couple months between n trims, I rasp a bit but don’t have the strength and skill to really work with knife and nippers. Sometimes she is just fine, no change after trim, other times there’s a huge improvement after a trim. I think unbalanced feet might radiate right up into her body. And these are very minor imbalances really. They are how she wears her hooves down naturally.

Oh I see you already did hooves.

Does she wear a blanket? Keeping warm in winter might help?

[EventingMaff]

Thanks Scribbler. She does wear a blanket but actually runs hot so we can’t blanket too heavily and she’s typically just in a sheet until it’s in the low 20s (F) at which point she’s in her 100g. She does have a BoT that I put her in before and after exercise.

My thought on the cold weather is that in the warmer months she’s moving a lot more in her turn out as she’s usually grazing (poor quality grass, but she’s not picky!). Winter months she’s usually just standing in her shed snoozing or eating hay so she’s actually not getting the benefit of turnout and clearing out her muscles the same way.

Not really anything we can do for that though as she’s boarded and BM has already gone ABOVE and beyond to adjust her typical care to suit mare, so asking her to spread hay or recreate grazing of any kind would be more than I’m comfortable asking.

[Scribbler]

Does she have pasture buddies? I used to turn my mare out for a few months every year with a small herd of TB mares who took everyone on fitness gallop several times a day. She came back super fit. But most horses alone or in a more laid back herd often don’t get the movement we hope for in pasture.

[EventingMaff]

No, she’s picky about her friends and there is only the one paddock that can have overnight turn out as it has a shed so she goes out solo in it (all other horses are stalled at night)

[Dbliron]

There are some major changes to contemplate. Pasture turnout is helpful with PSSM horses, so long as the grass is not stressed, BUT it’s not enough daily exercise. Horses with PSSM need daily “forced” exercise, either ridden or on the longe (or driven) for at least 10 minutes, every day. If you can do 20 to 30 minutes that’s all the better. In addition to having the horse tested, which I would do immediately, her diet almost certainly needs tweaking, starting with having your hay tested. You need very low NSC hay, which often grass hay is not, and you need to increase the ration balancer to the recommended amount, rather than 1/2 that. Working with a qualified equine nutritionist would help a lot. While PSSM 1 and 2 diets are similar they are not identical, so you need to do some research. Dr. Valberg is a good place to start!

[Equkelly]

I totally think PSSM2 is weather related. OP I would at least test for PSSM1 just to rule it out because the management for PSSM1/ PSSM2/ MFM are all pretty different nowadays. I have a suspected MFM/ PSSM2 horse and what I feed her would be really bad for a pssm1 horse so just do the test from UC Davis to rule out pssm1 and then go from there.

[KBC]

It is a constant monitoring game, and changing just one thing at a time so you know what made the difference.

Mine, right now, crossing fingers, is good on

24 hour turn out
Grass hay
Working at least 3, try to do 4 days a week.
Gets soaked hay cubes to mix in his Vit E supplement and Magnesium.
He is blanketed 24/7, something we didn’t do last year, and he was totally unusable all winter. Now he has a huge selection to mix and match, to cope with the huge swings in our weather.

I added Camelina oil to the mix about 6 weeks ago, and after 3 weeks I was convinced I wouldn’t order any more, now I think it might be some sort of miracle! He”s better (cross fingers) now than he has been for a year.

[EventingMaff]

Can you share your PSSM2 horse’s diet?

[Equkelly]

• Unlimited pasture/ grass hay
• 5-10 lbs alfalfa
• 3lbs Purina strategy
• 25g whey protein isolate

[JB]

@EventingMaff

Even if this is PSSM, there’s not much to change - that I’m aware of - in her diet or management as we, through pure blundering, have basically ended up in a PSSM routine anyhow.

Kinda, but not really. The rest of this depends on whether it’s PSSM1, or some variant of PSSM1

PSSM1 needs more fat. The amount of grass may be too much NSC for this horse, or maybe not.

1/2lb ration balancer is too little - need at least 1lb/1000lb, unless you have something like FeedXL showing that 1/2lb is all you need to “balance” things.

@EventingMaff

My understanding is that oil can be added if extra calories are needed - either because horse is thin (she’s not, she’s super easy keeper but in perfect weight right now) or because horse is “flat” in work (maybe slightly? but she’s been so uncomfortable we haven’t really been working her these past 2-3 weeks)

If it’s type 1, then yes the oil is the lowest volume way to get fat calories in, and without bringing additional NSCs to the mix.

If she’s some form of type 2, then it’s much more about protein - quality, and amount. If she struggles more in the cold, I’d be more suspicious of type 2. I’d definitely up the balancer, add whey protein and BCAAs and go from there

[FatCatFarm]

I have two who are heterozygous for PSSM, both Saddlebred x Percheron crosses. Dam (Percheron) ultimately tested as homozygous for PSSM. Both of mine, now 13 and 10, have been managed via diet and turn out. I evented up to Novice on both but these days only trail ride. The oldest did develop DSLD in one then both hind legs at the age of 10 post pasture injury, and is retired.

I feed Triple Crown Sr for it’s very low NSC count and supplement with VitE in winter when there is no grass. I supplement fat with BOSS, 2 cups daily divided into one cup at each feeding. My horses stay turned out 24/7.

The oldest of these two full brothers did show some sensitivity to cold when we first started eventing, but I switched his diet up to what it is presently, and there were no further problems. Little brother who is 10, had absolutely zero issues when we were competing, and none now when we are trail riding and we’ve gone up to the mountains and also to the beach. Neither is reactive about anything or sensitive to being groomed; they absolutely adore being groomed and scratched.

So my situation seems to have been more of diet management and no confinement. I have adequate but not lush pastures. In the winter, my boys have free choice grass hay via a round bale in a hay hut.

[ChocoMare]

If you’re on Facebook, join this group. Great info and assistance from around the world.

https://www.facebook.com/groups/10150115027635241

[GPjumper]

My friend’s guy reacts badly to cold, sugars, alfalfa and certain magnesium supplements. He is believed to have a variant of PSSM2.

[4horses]

I have a type 2 suspect. She’s never been right behind and swaps at the canter. She struggles with any kind of performance in hot weather. She seems to be more symptomatic as she ages. I sent her DNA into the University of Minnesota Pssm study. Hope they find something.

Currently trying 1/2 cup of oil in her feed and increasing protein. Can’t say it’s helping.

[JB]

@4horses

I have a type 2 suspect.

@4horses

Currently trying 1/2 cup of oil in her feed and increasing protein. Can’t say it’s helping.

That would be because Type 2 isn’t actually a glycogen storage issue that requires added fat to make up for the energy the horse isn’t getting from “carbs”

PSSM2 (and all the associated variants) really needs to be called something else. It was only called PSSM2, to start, because a lot of symptoms were similar but the testing was not producing PSSM1 results. But Type 2 is nothing like Type 1.

[4horses]

The research done in Quarter horses and related breeds suggested that they did better on higher fat diets even for type 2 pssm. However if I don’t see any improvements I may ditch the fat and increase the protein. She has thoroughbred in her but I’m not certain there’s research on what diet thoughbreds do better on. Really it is a guessing game. The only thing I can say for certain is that she has gotten drastically worse the past 3 years. She’ll be 18 in March.

[vxf111]

Type 1 and 2 management are pretty different (and somewhat contradictory) so it really helps to test and rule in/out at least type 1 if you can.

[JB]

@4horses

The research done in Quarter horses and related breeds suggested that they did better on higher fat diets even for type 2 pssm.

Can you link to some of that?

I don’t disagree that some added fat may help a horse in general. But the deal with type 1 is that they can’t use carbs, essentially, for energy, so the fat is used to replace that energy source. That’s why they also usually benefit from being fed more like an IR horse, with more focus on keeping NSCs down

But type 1 isn’t a “carb” issue at all.

I have a friend with a suspected Type 2 TB, and the more protein and quality protein she’s gotten into him, the better he’s done. Alfalfa did a good job. TC Sr did a good job (he does better on higher fat feeds but his diet still isn’t the high-fat diet of a Type 1 horse), but when she added whey protein and BCAAs, he really blossomed.

EquiSeq testing may be worth it for a symptomatic horse. I would never use them for an asymptomatic horse, since research by Valhberg is suggesting that a high % of the equine population (I’ve seen 70% tossed around) has 1 or more variants. But CLEARLY, 70% of horses aren’t actually affected. Meaning, just because there’s a mutation doesn’t mean it’s actually causing a problem. That doesn’t mean the variants don’t cause problems - clearly there’s an issue. It simply means - the variant alone doesn’t mean there is a problem. There are likely other factors that need to be taken into account to say “this set of things causes a problem”

That’s why Valhberg has not been able to find even any correlation between EquiSeq positive results with horses whose muscle biopsies confirm type 2 (of some sort). I think her research is in the process of being reviewed and validated for publication, hopefully soon. But she has spoken about it at a fairly recent conference, and those are some of the things she’s said or alluded to.

[greywithchrome]

I have a horse I suspect may have PSSM2 and am curious about your friend’s experience. Does she use “human” whey protein and BCAAs? Does she add the essential tri aminos (lysine, methionine, threonine) as well?

This horse otherwise gets beet pulp/alfalfa pellets with a VM supp, 10g magnesium, and 2000iu vitamin E.