At a Glance One hundred and eight cats. One hundred and fifty dogs. More than 500 color and black-and-white photographs. The "Harper's Illustrated Handbook of Dogs" and "Harper's Illustrated Handbook of Cats," by Robert W. Kirk, director of the veterinary medicine teaching hospital at Cornell University, and Roger Caras, special correspondent for pets and wildlife for ABC News (really), are the first books devoted exclusively to breeds of domestic cats and dogs recognized and available in the United States. Published by Harper & Row, $9.95.