America’s animals, it seems, have very American health problems. More than 20 percent of our dogs are overweight; Pfizer’s Slentrol was approved by the F.D.A. last year as the country’s first canine anti-obesity medication. Dogs live 13 years on average, considerably longer than they did in the past; Pfizer’s Anipryl treats cognitive dysfunction so that absent-minded pets can remember the location of the supper bowl or doggy door. For lonely dogs with separation anxiety, Eli Lilly brought to market its own drug Reconcile last year. The only difference between it and Prozac is that Reconcile is chewable and tastes like beef.