Talk to your vet. He or she might know of a better food that won't cause vomiting and one that's good for your cat's urinary problem. My kitten got terrible crystals and UTI when he was only 7 months old. It was bad. We had to source an antibiotic from the human pharmacy his infection was so bad. Now he's on one of the Science Diet foods for life. If I change him off, his stones could come back pretty quickly.
Again, your vet should be able to give you options for foods. And besides, with a 14 year old cat, you really don't want to take chance and get them sick. They are more prone to UTIs and they are more delicate.
