Yeah fat 'pockets' or 'pads' are a sign of insulin resistance(I wouldn't personally worry about testing him, but just assume he is). We can all stand to put on excess weight & stay healthy, but retaining it long term, without regular 'hard seasons' to use up fat stores is a big thing that reduces insulin sensitivity. That & high sugar/starch diet, and nutritional imbalance, particularly deficiency of Mg & Chromium. So those factors need to be addressed & corrected, hopefully before he develops serious health problems because of it.
If at all possible, I'd keep him at a setup that provides 24/7 turnout. Or at least a lot more than a few hours daily. If that's impossible, I think you really need to get him exercising for more than 3 quarts of an hour daily(sounds about what he gets). I also would hesitate to do much lunging & circle work, at least until he's not so obese. It's quite hard on their joints to do a lot of circling at the best of times. Take him out & about for long walks & trots, up hill is also good. Just watch that he gets enough 'breathers' & remember to build up gradually to harder/longer exercise, as an obese person needs to do.
How much & what sort of hay is he getting? It may be too rich - remember, while grass loses nutrients when processed, it loses little sugars & starch, so it may be just as rich as when it was growing, and a lot of hay these days is made from 'improved' cattle fattening pasture. If you can't get low NSC hay, you may need to soak & drain what you have before feeding, to leach out some of the sugars.
Why on earth is he getting any grain or other supplementary feeds if you recognise he's already obese?? I'd cut that yesterday, unless there's an extremely very good reason - which may be providing literally a single handful of low NSC feed to mix appropriate nutritional supps in.
So, I'd get his diet(as in scrap the extras, just the hay) tested so you can work out what nutrients he may need to be supped with, so you can find appropriate products. *I'd give extra Mg on top of the 'balanced diet'.
Last edited by loosie; 06-27-2019 at 05:39 AM.