this is what the vet hospital i worked for would sell to pet owners of dogs in casts/splints. its great for protection and has a non-slip bottom.
like all covers though, it cannot be left on all day. only when needed like going outside or pottying. otherwise it creates a warm environment inside the cast.
Dog Bandage Protection | Waterproof Breathable Dog Bandage Cover | Protect Canine Leg Injuries | Keep Dog Paw Bandage Dry| Medipaw Protective Dog Boot