Mud Bay 2750 77th Ave SE, Mercer Island, WA98040 Mud Bay, founded in Olympia, specializes in healthy pet foods, which are high in protein and have no byproducts. The…More knowledgeable staff prides itself on being knowledgeable about everything from the best foods for you particular pet to the toys best for different dog breeds. The store has a treat bar, which your pet can take advantage of as you shop. Your animals are welcome as long as they are on a leash. If you want to learn more about your pets needs, check out the store's informational pamphlets. Although focused mostly on dogs and cats, Mud Bay carries items for hamsters, gerbils and other animals. This store, one of 20 locations in Washington, is environmentally conscious and tries to stock locally made toys.