fat horse problem

["Sullivan's" <greymare@jps.net>]

I th ought I would throw this out in hopes of helping my friend with her perplexing problem.  She has an 8  or 9 year old gelding that she just cannot get the weight off.  He is some sort of Appy/QH cross, and is ridden regularly on hilly and hard rides several times a week.  He has seemed to, over the past several years, to have added continually to a layer of fat, that shows over his croup and is now causing a cresty neck. 

He has done several 50 mile rides, is very fit in terms of climbing steep hills, and can keep up a steady pace with my big Arab/walker cross.

 

He is ridden about twice as much as my horses, and keeps adding weight.

 

The problem may be partly that all her horses are on irrigated pasture, but even the ones that aren't ridden as much aren't this fat.  He is now pulled off the pasture into a dry lot (which really pissed him off), and given some grass hay. He gets no grain.

 

Does this sound like any kind of a thyroid problem or something similiar? 

 

Because of all his extra weight, he sweats profusely, and has problems cooling.  I see the kind of riding she does compared to me, and it just does not make sense.  At this point, with my big mare being ridden LESS, I stil have her currenlty on green pasture, give huge vats of soaked beet pulp and corn oil, alfalfa and grass hays......in the effort to keep the weight on her......and I can see she is dropping slightly.  If my mare is a condition 5 right now,  this guy would be pushing an 8......

 

Any ideas?

 

Karen