Our senior 12 year old pug Appa started getting weaker in his hind legs, and a year later could barely walk and was scooting around. The vet says he likely has Pug Myelopathy (PM). This size small wheelchair is the perfect size for a pug! He was so excited to be mobile again, both inside the home and outdoors. He was especially happy to walk along the beach again with his favorite ball. The wheels don't work too well on soft/dry sand and tend to get stuck, but the wet and flat sand is perfect. Going over grass lawns is also no issue. I seriously cannot express how happy this made him, it really feels like it gave him a reason to keep living. We tried a cheapo wheelchair off of Amazon a while back, and had to return it because it didn't work because it was made with such cheap materials. This device is hardy, well-designed, and Appa got the hang of it very easily. It's well worth the higher price point if your dog has paralyzed hind legs. Thank you Walkin Wheels!