Thank you everyone for your input I really appreciate it -- I should have added a few more details the bay pony is 25+ years we got her last fall her teeth have been checked and we were told they are very good for her age -- she doesn't seem to drop gain when she chews and does well with her hay (we do wet it for her to help her out a bit). We have switched hay suppliers in April (will never use them again) and she is now on very good quality grass hay which we put down all day for her (unlimited) but I now think that she needs a round bale which she can munch on at night as well? She also has some grazing (it is limited here as our pasture is not very good) She also gets 900grams of Purina Integri-T soaked to a mash (it's the highest protein/fibre/fat) complete feed that we could find in our small town. She is ridden very lightly by my 6 year old daughter maybe once a week. Other than the weight her health is very good -- she runs around like she is a 2 year old and is always happy and bright.
The appaloosa is not in foal (she has been vet checked) because we thought she was too when we got her before the winter she was a little more filled out (I do not like seeing her spine it seems to stick out on the top of her back) and it was not like that in the fall. She is just starting to be ridden/worked as she was a former broomare and not broken when we got her (could be why the belly?) and lack of muscle. She is also on the same hay/grass regimen as the bay and just a couple handfuls of 13% protein sweet feed mix.
As for worming -- they were both wormed twice in the fall/winter using Eqvalan Gold and once this spring using Bimectin and again two weeks ago using Eqvalan Gold again -- I have not seen a 'power pack' in our small town available can anyone explain what this is? As well I am not aware of the sand flushing -- maybe this will be beneficial as well (they are in a sand paddock for most of the day) can anyone explain how to do this as well .. ?
Again thanks for all of your input (any is appreciated as we are new at this)