I personaly would have that pony on a starvation paddock (i.e whisps of very very sparse and very poor grass) during the day and in at night on a soaked haynet of last years hay that had been double or tripple netted. It most certainly would not be getting any form of hard feed what so ever!
Okay. What I want to know is what breed is he? His confirmating looks like a fjord and they are typically a thick little horse. Granted I do agree he is a bit over weight and ought to have a vet look at him not just be starved and worked to death like some seem to be sugesting. Some breeds of pony/horse always get very think winter coats, some horses are built thick like drafts. I hate to jump to the conclusion that this horse is ill or uncared for becouse of his breeding. It sounds like th OP is doing the best she can by both the horse and it's owner. The only other options she has is to buy the hose and get the vet out herself or to take a chance at the horse being "sold for Glue" if she kicks it out and the lazy owner's parents get rid of it. I hate how on this forum a simple question turns into a "Your beating/killing/not caring for your horse right" board.... 1 comment with helpful hints should suffice ESP if you have no idea what the horses back ground and history or what the owner is curently doing about the problem. We have enough to stress over in our own lives to grip about some one elses to, don't we?
Horseplay - I shudder to think of your horses ifyou think that that horse is only a little over weight.
He has a condition score of 5 out of five, he is in the morbidly obese category. Yes some horses are stockier then others however that horse has the most enormous apple bum i've ever seen, it has a deposit of fat on its shoulder and a huge crest. I'm willing to bet that you would have to go excavating to find its ribs. The horse is at a huge risk of diabieties and laminitus as well as potentialy comprimising its joints and heart.
Thick winter coats do not give horses apple bums.
Too fat is just as cruel as too thin if not more so since people don't realise the harm they are doing.
I like my ponies slightly on the heavy side but one that fat would be on an extremly strict diet to get at least 100kg of weight off it!
This is my old connie at his fattest. He just has a hint of an apple bum starting and had a slight roll of fat on his shoulder but no crest. He went on a diet after this photo made me sit back and realise.
This mare is part draft, even she is fatter then I would have liked her and she didnt have much of an apple bum