If your dog won't leave his stitches alone, it is time for an Elizabethan collar. Commercially made Elizabethan collars, known as E-collars, are constructed of hard plastic and come in various sizes. Some are opaque, but recently, clear E-collars have become available. A clear collar allows your dog to see and maybe even get around better. These collars are typically available from your veterinarian or neighborhood pet store. In a pinch, you could try to make a temporary version at home.
For more information, please read Elizabethan Collars