I saw the shirt in "Pet Club" -- they have a very good selection of items and generally reasonably priced. I'm not sure how many stores are in the chain: I think it's only a half dozen or so. The one I go to is in Mountain View, CA and in the shopping center next to Costco. (I know there are a lot of Silicon Valley Pet Talkers who might be interested.)

Many thanks to toughCookie who sent me a variety of suggestions for the shirt... Great ideas. Wish I'd thought of them