Friday has a hyper thyroid. We recently discovered it and started him on meds. Prior to this, he was urinating and defecating outside of his box. His vet theorized that as he's aged, it's more difficult for him to get into and out of his box so I bought him a box with very low sides and added it to our growing collection of cat boxes. Once we started him on the meds, he resumed using his box with no trouble. He seems like he feels a lot better and is more active. But now, about two weeks later, he's pooping out of the box again. It can't be that it's painful to step over the sides because he jumps up on the wall behind our shower which is higher than my head and he still has the low sided box. Also, for urination, he uses the box with the highest sides that we have so I'm thinking there may be something else going on. We're due to go back to the vet's next week to weight him again, etc. and I'll ask the vet about it again but I wondered if anyone had any other ideas.
