Thanks, everyone, for your advice and good ideas. We took him to the vet, as above; he has Advita (a probiotic) to take now and is frisky this morning. I spent yesterday afternoon and evening digging up the approximately 350 Mt. Atlas daisies we have. I've got about 100 done so far, so he can't go outside until we get his exercise area completely free of them. He still has diarrhea this morning just as before, formed and then liquid, but is drinking water and seemingly feeling good. Folks should know about those Mt. Atlas groundcover daisies; they are not on the ASPCA list or any other list that I searched, but there are too many daisy varieties and sub-species for ASPCA to list them all. They are anacyclus pyrethrum var. depressus. This is a great forum, and thanks to all of you!