Our 10 year old, 165 pound Great Dane, Bob, has degenerative myelopathy, which causes loss of coordination in the hind limbs. His back paws wobble and knuckle under, and he started to drag his feet which was causing bleeding from the nails. He is now on his third set of Pawtrexx boots and his mobility has imporved considerably!! The cutest thing is that he hops like a bunny when running with the boots on. These boots have been a godsend!!