• I worked at a pet food store for 6 years that focused on education and nutrition was a huge part of that. Looking at the ingredients of that food I would guess it is because it has about 2x as much fiber as most cat foods. It also has added pro-biotics, so that combined with the fiber could really mess up your kitty’s gut. The fact that your vet won’t refill without a visit is odd (especially if the vet knows it is traumatic for your cat), but I can see why Chewy/Amazon won’t sell without a prescription.