Putting a well horse on a PSSM diet?

[Lord_Helpus]

For the 1 or 2 of you who do not know Goober’s story: In Jan, Goober (who is an immature, just barely 6-year-old) had some signs of PSSM (was not building muscle behind) so we did a muscle biopsy. It came back as “low level PSSM”. I asked the vet if there was a grade number to tell how bad it was, and she said ‘no’.

So, being a conscientious owner, I immed put him on the whole shebang of PSSM diet and exercise. After several months he was loosing even more muscle behind. So he went to NC State for a full body scan and neuro exam. Nothing new showed up (he has sidebone which I knew).

We were sent home and told to watch him.

LSS: He has gone on an Aquatred several times, and I have set him up to go there (beginning tomorrow) for 2 weeks for intensive treadmill work. But in the last week he is losing hind end muscle at an alarming rate (see photo – if I can get it to load). I am 1/2 convinced that his low starch and sugar diet is responsible for his incredible loss of muscle.

If course, today is a holiday… and my vet is closed. I do not know if I should take him for more intensive work if the diet is causing the problem.

Has anyone had my issue? Can a PSSM diet cause muscle wasting in a horse with extremely low PSSM?

NB: he has never shown any symptoms of PSSM. All this started because he was not building muscle… Perhaps this whole PSSM thing is wrong?

[bugsynskeeter]

What strain of PSSM? PSSM 1 and PSSM 2-5 are very different and require different diets.

[Lord_Helpus]

@bugsynskeeter

What strain of PSSM? PSSM 1 and PSSM 2-5 are very different and require different diets.

He has PSSM2. I have never heard of different diets for 1 and 2. Nor have I ever heard of 3 - 5.
I just checked my notes (voluminous) and still cannot find different diets.

[bugsynskeeter]

PSSM 3-5 are recent additions to the PSSM “family”. Is he on any amino acid supplements? What exactly is his diet?

PSSM2 horses need a higher protein content in their diet than PSSM1 horses do.

[sascha]

The horse in the picture has not just lost hind end muscle. The horse in the picture is darn near appallingly thin. Time to feed more and possibly put him on ulcer meds to see if there’s something going on there that is preventing him from eating enough.

Editing to add, I’ve put every horse I’ve had care and custody of for the last nearly 20 years on a high oil, low starch diet. Only one was diagnosed PSSM. Apart from my most recent horse who had severe ulcer issues, I have never had one look like that. Even then, once we got the guts under control, my mare went poof on “the diet.”

Do some math and some weighing of feed and checking of nutrients. Something is not right there.

[JB]

Yes, there is one place that I know of that tests for P3 (though 4-5 are new to me, will have to look them up), so it’s worth that test. @bugsynskeeter do you have a link handy?

There’s nothing about low sugar/starch that would contribute to muscle wasting. Low protein, yes. And low can be either outright low, or low in the context of P2/P3 which do require protein above and beyond what a healthy horse needs

What is his whole diet? Have you added fat while reducing the sugars?

I know nothing about this company in terms of reliability of testing, but this is who I know does a P3 test, aka myofibillar myopathy
http://equiseq.com/test_pssm2.php

[RedHorses]

Is he getting enough calories to compensate for the increased exercise?

He’s been on the diet for four months now? I admit that my research was done many years ago, but at the time it was common for horses to have a ‘relapse’ around 4-6 months into the new diet, after which the turnaround and improvement happened quickly. Is that still the case today? Mine had an incredibly difficult second month, getting closer to tying up than he ever had, but once through that he was good.

Going back to the calorie thing - the high fat diet reduces what the horse gets out of the hay part of the diet (I don’t remember why, again this was years and years ago) which is why horses don’t necessarily gain a great deal of weight when the fat content is increased.

Third thought - how low did you get the NSC/sugar/starch content? PSSM muscle dies if it’s fed too much glycogen and not other energy sources. The less muscle the horse has, the less glycogen is needed to cause muscle death, which in turn reduces the muscle mass available to handle the glycogen. It is a horrible spiral. Is he getting any grass now that we’re into spring/early summer? Could that have upset the balance of glycogen? You might be able to check this one with a blood test for muscle enzyme levels.

How does he feel when worked? The best explanation I could come up with for when mine was bad was that his muscles felt like dried rubber cement. They stretched reluctantly and sort of oozed back into shape rather than snapping back normally. When he’s had just a little too much glycogen stores he feels NQR as if he’s injured something and it is tempting to do a light work to see if the almost lameness gets more specific. I have learned to keep him working as hard as he is able on that day, and the following few days to help him clear the stored glycogen faster, but it took me a while to figure that one out. It happens rarely enough now that it can take me a few minutes to figure out what’s going on. It happened once last year when someone shared a bag of apples with all the horses in the barn (she now knows to make sure my boy is deprived) and while I realized it was an excess of glycogen during the ride, it did take a day or two to connect back to the story of the bag of apples.

[RedHorses]

Final thought, though at his age highly unlikely - Cushings.

Mine was diagnosed with Cushings when I asked about his difficulties in building muscle over his top line. The vet thought it unlikely, but the ACTH test came back positive. But mine was 17 at the time.

[IPEsq]

Oh my! Poor Goobs! What is his current diet? I think he needs to gain weight all over from that picture, not just the hind end. He likely needs a lot more calories but it would help us to know what he’s currently eating to give you suggestions as to from what source.

[Lord_Helpus]

His daily diet is:
6 qts Re-Leve (designed by KER for metabolic horses)
2C vegetable oil
5 (baby) scoops of Elevate (Vit E)
1 (baby) scoop of amino acids
4 heaping handfuls of Speedy Beet (with water squeezed out to remove the sugars in it and then fresh water is added)
3 small flakes of orchard grass/alfalfa hay (NSC = 4) when he is in during the heat of the day.
nibbling on 2" high grass (grass is mowed 2x/week with the mower to keep it extremely low) when out in his field (16 hours a day)

He is ridden in the morning with 5 - 10 minutes between 5 minutes working sets and is free lunged in my 80’ x 80’ round pen in the afternoon.
Between his 2 periods of exercise, he is in his 14 x 14 stall with 2 fans and a mister on him

What should I change?

PS If you look at his barrel behind the shoulder, then add in the belly which is white in the picture (from sunlight glinting off a very shiny coat) you will see that he is at a very good weight.

[bugsynskeeter]

@JB

Yes, there is one place that I know of that tests for P3 (though 4-5 are new to me, will have to look them up), so it’s worth that test. @bugsynskeeter do you have a link handy?

There’s nothing about low sugar/starch that would contribute to muscle wasting. Low protein, yes. And low can be either outright low, or low in the context of P2/P3 which do require protein above and beyond what a healthy horse needs

What is his whole diet? Have you added fat while reducing the sugars?

I know nothing about this company in terms of reliability of testing, but this is who I know does a P3 test, aka myofibillar myopathy
http://equiseq.com/test_pssm2.php

Equiseq is who is doing the PSSM 3, P4, px testing. The information on the testing I have seen in on the PSSM Forum on Facebook.

[JB]

thanks - I suspected it might be them, but couldn’t find anything on the P4/P5.

[piedmontfields]

@Lord Helpus

What should I change?

You ask “what should you change” but you indicate that he is at a good weight with good energy? Maybe you don’t need to change anything!

FWIW, even when following the key “rules” of a PSSM diet for my mare, I did find that it took some tweaking before hitting on what works well for her. In your case, I would think about the RE LEVE (yes, the numbers for NSC are good but maybe it just isn’t the right match in other ways–that can be a very individual thing) and the turnout (can he handle the amount of grass he is getting).

[bugsynskeeter]

Re-leve may just not work for him. Have you tried a different feed?

[IPEsq]

Based on the input of a couple of vets in my area who advocate a diet like what you are going for (including feeding RE LEVE), you may want to add more amino acids, especially lysine. So, up the “baby scoop” to “normal scoop”? You can also buy bulk lysine alone. I don’t know how much is in a certain volume of powder, but these vets advocate a minimum of 20g lysine/day for horses with symptoms like you describe for Goober. He’s getting some of that from the hay and the supplement, but how much would depend on the protein test for your hay and how much of the mix is alfalfa.

How many hours is he in the stall with those 3 flakes of mixed hay? You may be able to up that amount to whatever equals free choice for him during that time period if he’s running out of those flakes before he goes back out.

[JB]

@Lord Helpus

Goobs is NOT thin.

It was a reasonable comment because the first picture had me thinking he needed some weight as well. Not anywhere near approaching “appallingly thin” but thin. I just didn’t comment on it.

[quoteI would never allow my horses to get thin.
[/quote]

Many people never allow a horse to get thin, but sometimes it happens, especially when struggling to find a diet that is effective enough for a horse with metabolic issues.

Here are pictures of Goober in in April and May. Goobs is fat and shiny and moving beautifully – with his 12" overstep.

He does look in good weight, I wouldn’t worry about that. He’s not fat though lol

How much does that 6 quarts of Re-Leve weigh? Can you remind us what other feeds you’ve tried? Just because something was designed for metabolic horses does’t mean it works for all metabolic horses.

What is the “baby scoop” of amino acids? How much lysine and methionine does that provide?

If he’s PSSM2, he could be that sub-type 3, which will require more protein than he’s getting

Sugars in grass accumulate closer to the crown. The shorter the grass, the more sugars there are in each bite. 2" means a lot of sugar, relative to the amount of grass. Eating that 16 hours a day could result in quite a lot of sugar, and may be a problem 2" is also not healthy for most grasses.

Letting it grow between 4-6" is healthier for it, though it will also allow him to consume more, as each bite will contain more grass. Whether it’s more sugar is too hard to say.

For the health of the grass, I’d let it grow. For his sake, I would muzzle him. He’s got a metabolic condition which does not allow him to use sugars like he should, so they have to be reduced. Low NSC hay for 8 hours isn’t doing much good if he’s eating high NSC grass for 16 hours. So that’s the first thing I’d change.

[knic13]

@Lord Helpus

He has PSSM2. I have never heard of different diets for 1 and 2. Nor have I ever heard of 3 - 5.
I just checked my notes (voluminous) and still cannot find different diets.

Where did you send the muscle biopsy? If your vet hasn’t provided you with the full report I would request it. Dr. Valberg provided a detailed report including histology and recommendations when I had a muscle biopsy done for my horse.

The low starch, high fat diet was developed for PSSM1 horses because they have issues with improper glycogen (carbohydrate) storage that lead to symptoms. PSSM2 encompasses a number of other muscle myopathies with sometimes similar symptoms but differing histology (appearance of muscle on a microscope slide). These horses may be sensitive to non-structural carbohydrate levels in the diet but not likely to the same extent as PSSM1 horses and there is a focus on quantity and quality of protein provision to support protein turnover.

The Michigan State College of Vet Med website has a lot of helpful information in understanding the different types of PSSM and other muscle myopathies along with diet and management suggestions for each type.

https://cvm.msu.edu/research/faculty-research/valberg-laboratory/what-is-equine-myofibrillar-myopathy-mfm

The 3-5 are supposed genetic variants promoted by a company doing genetic testing. To date, they have not published their findings, so you have no idea what these “variants” are or the relevance. This may be a great diagnostic tool in the future but I would be very hesitant in making decisions based off it with the given amount of information.

2 cups of vegetable oil on top of re-leve is likely overkill on the fat concentration on the diet and limiting hindgut fermentation of fiber. Re-leve was designed with higher fat than many commercial feeds so that people did not have to build PSSM1 diets from the ground up with individual ingredients. Thus, your horse won’t be able to generate energy as effectively from the forage component of the diet. What is the NDF/ADF of your hay? Your horse is probably not extracting as much digestible energy as presumed from hay.

Crude protein level in the Re-leve is moderate, more info needed on the amino acid supplement but ultimately it looks like the current diet is slightly limiting in energy so the additional amino acids are probably being diverted toward energy use rather than lean muscle accretion. Based on the photos your horse is not appalling thin by any means but not fat either and your horse simply won’t be able to build appreciable amounts of muscle if the majority of nutrient intake is diverted toward maintenance and activity energy needs.

[Pocket_Pony]

Is his blood work normal?

[Lord_Helpus]

Thank you all for the excellent replies. My Internet is down so I am sitting in my car a mile away from my house, which is the closest that I have two dots. The technician comes tomorrow and I will reply then. It is a terrible thing to live without the Internet:cool: I might have to clean my house.:eek:

[Lord_Helpus]

Yea! I have internet (sporadically). JB thanks (as always) for your insight. I have written it all down.

1. “big” and "little scoops refer to the size of the little “scoops” that come inside each jar of supplement. the scoop for the Elevate is very sall (he gets 5 scoops a day). The amino acid scoop is larger and he gets 1/day (per the label).
2. I am aware that grass intake is the loose variable. I bought and tried a muzzle. it was too small for him, but I made him wear it for a while. he hyperventiated and kept trying to get it off on the fence line. After 1/2 a day I took it off and began my grass mowing. The field management guy will be here next week and we will discuss it.
3. His bloodwork all came back normal. I will have blood drawn for glycogen and muscle enzimes. I will also look up the totals of all components of the ingredients in his diet.

When he is ridden, he is lovely. But after 3 walk breaks and, after 3x 5 min. exercize/training work, he hits the wall. His hind legs shorten their forward arc and he loses his spark.

Up until a month ago, his hind end just looked relatively light on muscle, and he showed exercize intolerance. But his happy-go-lucky attitude, and willingness to train was undiminshed. But a month ago his hind end musculature began to decrease rapidly.

NC State doesnt know what to do (as always), so I came up with the treadmill idea. A vet owns the place and will be overseeing G’s progress. I will go over 1x/week to see how he is doing.

Goober has an appt for next week to have his 3rd testicle (or whatever is in there) removed. I am trying to do everything I can to eliminate all variables that will worsen his condition.