i have a 30 year old qh gelding that is loosing weight and acts like he cannot swollow. ive had him wormed regularly and had his teeth floated. i feed him senior care pellets and have tried mashes but he wont eat them. a vet told me his muscles in his neck collapse his throat so he cant swallow. he told me i should just put him to sleep because he was TOO OLD. what do you suggest?