I would only use a vet nutritionist for home cooking. You can get a free diet at
www.balanceit.com It is run by a vet nutritionist and they are VERY helpful if you need to telephone them. You do need to set up a profile on their website and they will contact your vet for an ok to formulate the diet. You do have to purchase their supplement, but you need supplements! .. and the bottle lasts for about 3 months for a yorkie.
As to Hill's RX foods. I have pups on their RX foods...I have long trusted this company. I checked the lot numbers and continued to feed these foods that do save lives! I have a foster on Hill's UD (he likes it, but I have heard that some don't), a personal pup on Hill's Ultra ZD and a foster on Hill's Low Fat ID. It is the first time I have seen Hill's have a recall with their dog foods. It was unfortunate but I trust they have fixed the problem.