Morbidly Obese Horse not losing weight!!

*posting for a friend*

My friend is looking for advice on what to do. Her arab/morgan mare (Amber) has always been over weight. She basically had no human interaction (or very little) before two years ago when she got her. She was just kept on pasture 24/7 with access to hay and grass. Since my friend bought her, she had been slowly increasing her work periods and amounts of exercise and is now to the point where Amber gets long and hard-er workouts, daily (with breaks occasionally). Although she is getting much more exercise (and is very in shape) she has not lost any weight. If anything, she's gained weight!!
The vet came out one day to check out another horse and saw Amber leaving the barn after a good ride. He asked if she was pregnant! There is no possibility that she is pregnant because we have no stallions on the property and none in the area. The vet suggested putting her on a diet but I was thinking it might be a more serious medical problem. It's not affecting her at all really but it's concerning us all because we don't want her to founder in the future or possibly create new medical issues. It's also getting quite difficult to find saddles to fit over her table back !!!
Any suggestions on a quicker weight loss plan/diet and possible feeding schedules? She boards her horse at a stable near her house so will be out there daily but will not be able to do any nightly feedings or w/e because she does not live on property.

What is the horse being fed now?

Is it still on 24/7 pasture?

If so, a grazing muzzle is your friend.


Step one of figuring out a diet is first determining what the horse is eating now. Have the hay tested. Weigh the hay and grain rations.

Sorry for not putting that above, I should've been more clear. She is still on pasture 24/7 with free choice hay in all seasons, but I don't know of any horse that would choose hay over grass. She is not on any other feeds currently as we are still assessing the situation. I can talk to her about types of hay and weighing rations, but any suggestions?
I will suggest a grazing muzzle to her.
She had her separate from the herd with just one other horse in an area where there was grass that had mostly been eaten right down (there was still food obviously but not as much as in the fields) and was given small rations of hay periodically but it didn't seem to help much.

Laugh. Surprisingly yes, I do know a horse that eats all his hay before going back out to graze on the field some more.


It sounds like a grazing muzzle is in order. It greatly helps decrease the amount of grass they can get in.

Hahaha ^^wow. Well all horses are different I guess!

Also, just a question mostly for myself..
We have a selenium deficiency in our area and I was told that selenium helps with muscle building. Would it be a good idea to put our horses on a selenium supplement? Or are there other feeds that would be a good investment?

There are others that know way more than me, but if she was mine, I'd cut out the free choice hay and limit her grazing to during they day and then be put up (stalled) at night. See if that, along with exercise makes a difference.

I was going to suggest the same thing, except I'm not sure if stalling would be an option at the stable she's at. Should she still be kept on hay though? But just rationed?

To me..if she has good grass for grazing then she shouldn't need free choice hay. My fillies who are on grass don't get anything else...and they are put up every evening.

Holy cow- my horses (who aren't hard keepers but aren't easy keepers) don't even get free choice hay AND grazing! If the mare is that over weight she needs to be cut off- I am not sure why your friend would keep feeding her so much.

Stalling her and cutting back her feed is the best way to get weight off... keep in mind that you need to do it slowly though- you can't just take her down to (for example) one flake in the am and one flake in the pm.

How tall is she?
How much does she weigh?
Is she stocky or fine boned?
What kind of hay is she getting right now?

Most horses that are on grazing don't need a lot of hay (unless they are hard keepers).

No need to take her down slowly. Laugh. Smack on a grazing muzzle and let her figure it out.