Hi Everyone, 

I purchased a 3 yeard old Brookston Bay(First down dash)/Deans Miracle colt this winter. He was thin when I got him and have really been putting the hay to him. He has a great appetite, eats, drinks however he won't gain a pound. He looks lanky and thin and even sucked back in the flank area. His teeth are good. Does anyone know if this is just the body type? I have zero experiance with horses that are not cow bred and my mares are all twice his size. Any helpful comments or advice would be great. 

Could be a number of things, could be uclers, need to be dewormed, better feed or could be just the way he is, one thats just a lanky looking colt untill he hits that age where he'll stop growing and start filling out..But I would look into uclers just to make sure his gut is good. The sucked in flanks kinda tells me its uclers..

Do you have any pictures?

Agree. Rule out ulcers and get on a good gut supplement.

But in my experience they start to look good and then grow again and look lanky and ridiculous, and then start to look good and then they start to grow again..... And the cycle goes on lol 

I agree. Check on ulcers and maybe get him on a good probiotic. Worm him again (maybe powerpack?). Once those things are done, if they haven't started to put on some weight in 3-4 weeks then starting looking other places. And it never hurts to talk to vet if you are just worried about it.

Ive had several FDD grand get and a daughter of Dean Miracle.  All were easy keepers. 

I agree with everyone else on a good gut supplement. THE Gastroplus is wonderful and affordable if you suspect ulcers. Forco is good for gut health.

Thanks everyone..I will check for ulcers. He's going to be a beauty eventually. He's tall and has good bone structure. Here is a picture I snapped last night although it doesn't really show what I am seeing. It is quite possible I'm just over thinking which isn't uncommon lol

from what I can see he looks in good flesh to me, since hes only 3 hes probably just in a growing spurt.. What are you feeding him and is the hay good quality? 

I would treat for ulcers, like other posters said.

However, I would also take a side photo today, and another one in 30 days. If you look at a horse every day, its hard to see the changes.