Medium size Any small dog up to the size of a STAFFIE will be suitable for the medium Hound Sleeper. Two JACK RUSSELL’S, PUGS, YORKIES etc will fit on one medium size together. Large size BULL TERRIER size up to a BOERBOEL, GOLDEN RETRIEVER, ROTTWEILER, GERMAN SHEPHERD, and LABRADOR dog for the large Hound Sleeper. XLarge size GREAT DANES, ST BERNARD’S, IRISH WOLFHOUNDS. Two large dogs can share one of these XLarge beds.