I personally wouldn't over think the dry food thing, ideally a can or two might help with the hydration but just do what works best for your cat. All are different and have different needs.
As for urine samples, it's best to have the vet take it directly from the bladder. If your cat is anything like mine he may not like the perler bead stuff and protest by peeing on the living room rug.
As for urine samples, it's best to have the vet take it directly from the bladder. If your cat is anything like mine he may not like the perler bead stuff and protest by peeing on the living room rug.