Three rescue groups that specialize in finding homes for large dogs will get some extra dog food for their cupboards after a special benefit Saturday. Vicki Tri, a fitness instructor from south Oklahoma City, invited people to a free boot camp-style exercise class at Earlywine Park, SW 119 at May. About 40 people showed up for the early-morning outdoor class and contributed 750 pounds of dog food, Tri said. The food is being donated to Great Plains Mastiff Rescue of Edmond, Rotts-N-Notts of Oklahoma City and Heartland Great Dane Rescue of Guthrie. For more information or to contact Tri, e-mail email@example.com.