I had a pony that got straighter as he lost weight, and a horse that got more curve as the same happened. No withers and being fat is neither mutually exclusive nor mutually inclusive. Fat can decrease the appearance of a wither the same as lack of topline can make a large/medium wither appear larger. However, some horses and ponies just have no withers AT ALL - my little welsh that I sadly sold a couple of months ago was one such pony, in very hard work (2+ hours EVERY day and he would be dripping with sweat by the end of every ride) - he was only just staying at nice body condition and we were only giving him his suppliments, grass hay, and grass (he used to eat the suppliments straight out of your hand) - and he had no wither no matter what. Tough little blighters, these Welshies. Bred to go all day and they can (and quite often do, if they're school ponies) manage just that.
I would have an equine dentist look at her teeth if you can, that's really the most reliable you're going to get. The equine dentist will know EVERY little marker of age as they will have been trained to look for these things - we don't necessarily know what to look for. I can tell between a young horse and an old one, which is helpful if you have a horse with a brand (you can tell if it's 6 or 16 pretty easily) but if you don't have that definite she IS either this or that, then it's hard to know for sure.
I won't pretend to be an expert but I see a lovely pony there that I would love to have - and I hate managing ponies!!
Last edited by blue eyed pony; 06-27-2011 at 10:59 AM.