Thanks, all of you for your concern and suggestions. Fozzie is still free of fleas this morning.
September, the yard spraying by a commercial company is a good idea. I am holding off on this, however, because of two reasons: I have a garden in the back yard, and I'm concerned with chemical runoff into it. Should I be concerned? The other reason, an immediate one, is that I go today to get my twin grandsons, age 6, who will be in the back yard occasionally. After their visit this week, I will re-assess the problem.
Interestingly, the other night when I first posted about the pup crying, I was doing a lot of research, and someone had misted their grass with Pinesol and said it helped. I went out and did this in the dark with a strong solution. It seems to have helped, but it may just be my imagination!
Patty