21 year old mare

Question
There is a 21 year old mare in my barn that I lease out to another party. The mare is theirs. She can not eat regular hay. They have been giving her some sweet grain with beet pulp twice a day, I don't know how much she gets, it takes her probably 20 min to eat. She stays in at night with the other horses, and goes out with them during the day to eat from a round bale of first cut hay. She comes to the gate often during the day and whimpers.The owners say she is just grain crazy. I bought her some second cutting grass hay, I fed her 1 leaf a day which she seems to eat quite well, and seems to keep her happy, they asked me to stop giving it to her yesterday, and I feel so bad to deprive her of it. I can't think one leaf will matter that much. We live in upstate NY and it is below freezing on most days. She has no blanket and since she is so skinny, it breaks my heart to just walk away. They are the horse people, I'm not, but I think I know a hungry animal when I see one. Do you think that she will be okay until spring and green grass. Thanks, Carole

Answer
I am a little confused. You say she cannot eat regular hay, but she eats from the round bale and you were giving her hay? She must be able to eat it..? Older horses can have bad, worn out teeth. The beet pulp is fiber. They are giving her that for roughage. It can take the place of hay. Does she chew the regular hay and then spit it out, or does she swallow it? You can't tell when a horse is hungry because they are always hungry. They will literally eat themselves to death. There stomachs are very small and food travels through their quickly. If they eat too much grain it can cause colic. There is no danger from eating too much hay. I assume there must be a dental problem. There is nothing you can do since she is not your horse. You have to follow the owners wishes. Older horses are also prone to be underweight. She is probably just showing her age.