Walkin' Wheels for Handicapped Pets - Small lets your elderly, disabled, or special needs dog run, play, and get the exercise he or she needs to live a happier, healthier life.Experience the simplicity of Walkin' Wheels for handicapped pets. No more complicated measurements and waiting weeks while carts are built. Walkin' Wheels ships immediately and is adjusted in minutes - no tools needed - with simple snap-locks. Ideal for dogs with rear-end mobility problems including arthritis, hip dysplasia, degenerative myelopathy, disc disease, and more... Small Breed Size Range: Length of dog from back of the front leg to the back of the rear leg 5 to 9 inches. Height of the dog, groin to ground 2 to 5 inches. Width of the dog at the widest point, 2 to 5 inches.