Basically she said that as long as your cats aren't having a reaction and you are keeping the bowls really clean like putting them in the dishwasher or washing them in really hot water, it should be ok. She seemed to lean toward stainless steel OR regular china or glass. I have a ceramic bowl that I thought was quite poreous but when I looked at it more carefully last night it's quite smooth on the inside so I'm not going to get rid of that one. I have plastic for all the other dishes and some of them have lids, which I use for travelling. I'm not going to get rid of those either, I'm just going to switch to glass or stainless steel for everyday use.

If your cats are fine and the dishes are cleaned well I don't think there is a problem with the porcelain