An exercise guide that recommends everything from sit-ups and ""pumping iron"" to Jacuzzi baths and cha-cha dancing--for pets--is hard to take seriously, even when the authors are noted animal trainer/behaviorist and TV personality Warren Eckstein and wife/partner Fay. The Ecksteins, who share their home with over 50 dogs, cats, and other creatures (including a pet pig who at 500 lbs. had to give up his favorite sport--skateboarding), make a cogent argument for the importance of aerobic exercises, which increase physical endurance. A carefully planned and organized exercise program, we're told, is beneficial to any pet's physical and emotional well-being. Most useful are chapters on how to transform activities that come natural to pets--running, swimming, ball playing--into enjoyable regimens. Given the large number of overweight and sedentary pets, the Ecksteins' many sensible tips, as well as some of their lighthearted suggestions, might well be taken up.