stumbling horse

[Bob Davis <bsdavis@kansas.net>]

Title: stumbling horse

hello,
I'm usually just a reader on this list serve, being such a beginner to this
sort of riding.  I rode as a kid, did some rodeo event in high school.

I need some advice on a horse that has a really bad stumbling problem
and who also had a bad time recovering today.  
A little history:
I have a small (almost 14hh) mustang that is 5 yrs. old, broke, but no
in-depth training.  Last year I had three falls: first, the mustang front
end goes down at a really slow trot when I corrected his direction, and I
literally walk off over his head (freak of luck) he goes all the way down
and roll;, second is a thoroughbred-type lesson horse where I take english
lessons,
third, mustang stumbles and goes down in front.  Third one was the charmer as they say.
I slid down his neck and when I was on top of his head he regains his
footing and I get a flying lesson.  Helmet probably saved my life
everytime...even though I was really one hurting hombre on that last one...

Having asked a few folks about his stumbling, most answer that he's just a
youngster and hasn't been watching where he puts his feet.
Well, I've been putting some miles on him in the last month as we just
started our LSD, and today it was worse than ever. He probably stumbled 5-6
times in front (never going down to knees though, and his back feet kind "gave way"
 under him 2-3 times.  He was
also in bad shape from a respiratory perspective too.  I was pretty scared
and just worked to cool him (sponged down with a 5 gallon bucket of water),
but he was still panting fast and wasn't getting any better.  I decided to
get him in the trailer and head for home (only live 3-5 minute drive away
from area.)  Got him home, ran alot of water on front end and he got better.
We had rode less than an hour, at walk/trot we've been doing for two-three
weeks now, although it was hot and humid.  This was also the first morning ride, as
we normally ride late evening, but I did FEED him a little more than usual
to get him in the trailer (small coffee can almost full (about 3 cups), and he'd been
grazing all night so it wasn't on an empty stomach).
We had a bad ride on Tuesday, rode a rocky trail and I could tell it really
hurt his feet so I got off and we walked last half back to grassy area, but
he also seemed really tired that day.  That was the first time he didn't seem
full-of-it for the whole ride, even when we get back to the truck, he's usually wanting to turn
in on the trails and go again.  So I gave him a few days off.  Light ride
Friday night and then this morning...He could barely make it back to the
truck.  What did I do wrong, this was not normal for him?  Too hot, too
humid?  Feet still sore? (rode only good grassy dirt trails today and they
didn't seem to be bothering him).  No limp, but stumbling worse today than
ever.

He seems healthy and has a good appetite.  He is overweight, being one of those horses that gains weight just thinking about supper...

Any ideas?  My vet hasn't suggested any sort of tests and doesn't have any
ideas. He's gonna get shoes this week.
I'm beginning to think he's not going to be ride-able! I'm really scared
he's gonna go down with me again. I'm also very worried about his condition today, it
scared me.
I need some help here...I don't have enough experience to be judging this
situation.  I would welcome any comments and thoughts.  I'm not sure what to
do at this point and I don't want to put my horse in danger.
sorry about the length of this post, but I figured if I was going to ask for
help, then I better give a good scenario.  I can't think of anything else to
add to the picture.
sherry and hudson