Murdoch's - Wildology Logo Ball 4" Mesh Bag 6 Pk. These are the first tennis ball designed specifically for dogs. Petsport has sold these industry leading balls for over 20 years. The 4" Murdoch's Balls have super thick natural rubber walls for extra durability and better bounce. Murdoch's Balls also use polyester felt which is safe on dogs teeth. The completion uses wool felt which can wear a dogs teeth down. Murdoch's 4" Tuff Balls are non-toxic and are safe for dogs and the children that play with them. | Pet Sport Murdoch Tennis Ball 6 Pack in Orange | Size 4"