DAN: "PSSM types 1 and 2, which we've already kind of talked
about here.
What's the difference?
How to manage in terms of diet, exercise, and feeding,
any supplements that help?
Which is worse in terms of maintenance and quality of life
for the horse?"
Haley's going to get all her questions--
DR LYDIA GRAY: Yeah, so I'm going to hold you
to making sure that I answer.
DAN: I will check--
I will make sure we check them off.
OK.
So, PSSM types 1 and 2, what is the difference?
DR LYDIA GRAY: OK, go.
All right, well, I think we should maybe
explain what PSSM is.
DAN: Yes.
DR LYDIA GRAY: So the letters stand
for polysaccharide storage.
So that's PSS-- myopathy, M. And now
that I've introduced those big words we have to tell you
what the words mean.
So polysaccharide is just a big, fancy scientific word
for an abnormal glycogen. Glycogen
being the storage form of blood sugar or glucose.
DAN: Got you.
DR LYDIA GRAY: Storage, so it's an abnormal way
of storing abnormal sugar.
And then myopathy just a Latin word
for a muscle pathology or muscle disease.
So when you store glycogen wrong in the muscles
then you have a muscle disease.
DAN: So these horses don't store sugar correctly and therefore
have a muscle disorder.
DR LYDIA GRAY: Right.
And the muscle disorder is a, here
we go again, a rhabdomyolysis.
And that just means that the disolution or the breakdown
of skeletal muscle-- so the muscle you use to move
your skeleton--
through exercise or associated with exercise.
So that's basically tying up.
All right.
And there's a couple of forms of tying up.
There's the sporadic which happens
because it was extra hot that day
or you had injured your horse in a 50 mile endurance ride
and you hadn't been training for it and so he tied up,
he cramped.
That's sporadic.
The other chunk is chronic.
PSSM fits under chronic, meaning just the horse keeps having it
on and on.
It's not a one time thing.
So PSSM type 1, they have further broken this down.
There's a lot we don't know about it,
but there's a lot we do know.
So I can just--
I can just share with you both of those things.
The parts that are like fuzzy and the parts that
are pretty well hammered out.
And, by the way, Dr Stephanie Valberg,
she's now at Michigan State University.
She is the world's expert at any sort of muscle condition,
but especially PSSM.
And so you can go to MSU's website and read all about it
because we're not going to be able to cover everything here
that wouldn't do.
So I'm just giving you the framework
and then you go fill it in yourself.
But she found these horses that tie up and then the vets
did a muscle biopsy--
they took a chunk of muscle out.
And then Stephanie, Dr Valberg, looked at it
with special staining under the microscope
and found this abnormal glycogen--
abnormal amounts and abnormal look to it.
And they studied it and they studied it and they studied it.
And in 2008 they found the genetic marker for it.
So it is now a disease because it has a cause.
They found that there is an enzyme that
makes this wrong glycogen. It's called glycogen synthase
and it's abbreviated GYS1.
We used to have to send in muscle biopsies
to diagnose it once we thought maybe this horse has PSSM.
Because, in a quarter horse, they tie up.
So that's stiffness, pain, sweating.
They get really hard muscles over there the loin,
the hindquarters, the back end.
And they have to stop working because their legs just
won't work anymore.
They take these very short stiff steps.
But now we can send in just blood or hair.
DAN: Which just so less invasive.
DR LYDIA GRAY: And there's a genetic test.
So then, we had these Warmbloods and some other breeds
that were not-- they weren't tying up,
but they had this unable to localize weird gait
abnormality.
The vets were looking at them-- it
was a shifting lameness and it was hard to describe.
And they would look at the joints
like the hocks and the stifles and they
would look at the muscles.
There was nothing wrong with any of the usual
like the tendons and ligaments.
Everything was good.
And then they ran-- they did muscle biopsies and some had
abnormal glycogen and some didn't.
And so they said, well, we think we have a new group here.
And so she called them "that which is not type 1" Which
another name for it would be?
DAN: PSSM 2?
DR LYDIA GRAY: Type 2.
So that's the Warmbloods.
90% of Warmbloods have type 2.
DAN: Interesting, OK.
DR LYDIA GRAY: Arabs--
DAN: So breed specific?
DR LYDIA GRAY: It's very breed specific.
Arabs have PSSM, none of them will have type 1.
They all have type 2.
DAN: Even Arabs, OK.
DR LYDIA GRAY: Yeah, 100% of Arabs will have just type 2.
They do not get type 1.
DAN: Wow.
DR LYDIA GRAY: Yeah.
90% of Warmbloods will have type 2.
Not very many of them get type 1.
DAN: Are there certain breeds who get type 1?
DR LYDIA GRAY: Quarter Horses, Belgians, Percherons,
really high prevalence in those two breeds.
Yeah.
You're getting it now.
It's complicated.
DAN: Yeah.
DR LYDIA GRAY: It's very complicated.
The really interesting thing that she was able to find
was, in Quarter Horses, whether they have type 1 or type 2,
their clinical signs are tying up.
So that muscle pain and stiffness and sweating
and the firm rock hard muscles in the hide, the cramping.
Warmbloods, when they get it, they just don't perform well.
They under perform.
They're termed "lazy."
You kick them and they don't go.
They're unhappy in their work.
They don't-- if they're a dressage horse,
they don't collect.
They don't engage.
They have trouble with flying changes.
They have trouble with canters and pick up
the canter making lead changes.
So it's very, very different.
Now, her question was, which one is worse?
Kind of the type 2.
Here's why.
When Dr Valberg did her-- well, how
do you fix this problem, PSSM?
She said, there is a specific diet and a specific exercise
program.
And the vast majority of Quarter Horses with PSSM 1 improved.
Like, cured.
Although, we wouldn't use that word, because you still
have to manage it.
Because if you don't manage it, they go right back.
DAN: So through diet and exercise
you saw an improvement in the symptoms?
DR LYDIA GRAY: Yeah.
DAN: OK.
DR LYDIA GRAY: That's type 1.
Type 2 is not so black and white.
Most of the horses improve with diet and exercise but not
all of them.
And the ones that do improve, not as well.
The other problem with PSSM 2 is it's not a disease--
one single cause that you can test for genetically.
She thinks there are a wide variety of reasons that horses
have that which is not type 1.
DAN: Well, I was going to say, because it
sounds like for type 2, we're just ruling out
that it's not type 1.
So it could still be a variety of other things
that are causing it?
DR LYDIA GRAY: It's still a muscle problem
and it's still a glycogen--
now it's a glycogen clumping.
DAN: OK.
DR LYDIA GRAY: As opposed to abnormal glycogen or too much
glycogen being stored.
They clump weird.
So they don't quite have it all ruled out.
So that's what I meant by there's a lot we don't know.
DAN: Got you, OK.
DR LYDIA GRAY: Yeah.
So I would recommend go and read on Michigan State University
about PSSM.
DAN: She did ask you about something
and you touched on it a little bit.
DR LYDIA GRAY: Diet and exercise.
Yeah.
I know.
So the main recommendations for diet
are remove the sugars and starches.
Because if it's a glycogen, or glucose storage disease,
if you don't have glucose to store you get better.
So take away the sugars and starches
and then if they need fuel or calories or energy
for their work or just their weight you add back in fat.
DAN: So when you say sugars that's going
to like the hays and grain.
DR LYDIA GRAY: Grain.
I'm talking about the simple sugars.
So fiber.
Horses need fiber.
You keep the hay, but you want a low NSC
or low non-structural carbohydrate hay.
And that would be about 12% is what everybody is recommended.
And if you analyze your hay to say 15% or 16% then
you can soak it in remove or leech out the remaining sugars
that your horse should not have.
Pasture is probably off limits.
So either don't turn them out or you turn them out
with a muzzle just to slow them down a little bit.
But you don't feed them grain you
might feed them a ration balancer
to prevent them getting more sugars starched than they need.
DAN: And then if needed add in a fat like the CocoSoya
we talked about earlier.
DR LYDIA GRAY: Yeah.
And so that's diet.
And then exercises is, these horses need as much
turnout as possible.
I read somewhere, probably from Dr Valberg,
that they should not be in a stall any longer than 12 hours.
And I have a horse with that and so
I realize that when he is stalled
more than 12 hours like at a show,
he can't do his job the next day.
DAN: So they need to be out moving around?
DR LYDIA GRAY: They need to be-- so turned out all the time,
but they need control exercise, also.
And she's been very specific with the type
2 horses that a long, slow warm up with long and low frame.
Do you know what I mean by that?
DAN: So they're a little more rounded.
DR LYDIA GRAY: Yeah.
Don't put them into a collected short frame right away.
And, when they are warmed up, and you
are in the work phase of your program,
give them frequent breaks.
So don't ask these PSSM 2 horses to stay up and collected
and together for your whole ride, because they just
can't do it.
They need a break to release that muscle tension.
DAN: Those are some great tips right there.
DR LYDIA GRAY: Yeah.
DAN: For a complicated subject you handled it--
DR LYDIA GRAY: Oh, gosh.
DAN: --very well.
DR LYDIA GRAY: It's really hard, you guys.
DAN: And you said turnout, Haley's first question
was about the turnout boots and splint boots, so.
DR LYDIA GRAY: Oh, it all
DAN: They kind of go--
DR LYDIA GRAY: --makes sense now.
DAN: --hand in hand there for you.
[CHUCKLES]