Discusses the role of dogs in research, considering their use in studies related to: behavior; aging; anesthesia; gastrointestinal surgery; the brain; organ transplants; radiobiology; trauma and shock; arterial diseases; hemophelia; ophthalmology; diabetes; nutrition; cancer; lupus; cyclic neutropenia; thyroiditis; hepatitis; skeletal system, fracture, and related studies; pharmaceutical testing; and other areas. (JN)