In general, selective breeding has made great improvements in increasing the padding/fur/wool on the feet of most rabbit breeds. So sore hocks isn't quite as common as it once was. However, some breeds like Mini Rex, Rex, or heavier breeds are still more prone to it. Sometimes it's a genetic quality (they're from pet breeders or backyard breeders) and sometimes it's just the environment.
Preparation H clears up sore hocks quickly. Bag balm is also great for keeping the area moist and helping it heal.
Some rabbits will always have a rough, sometimes hairless, callus on their heel or toes. This is something to keep an eye on, but not necessarily something to worry about. You only need to put medication on if the area seems to be painful, inflamed or has open wounds.
Sore hocks may be prevented by housing your rabbit on a solid floor, but it doesn't always help. A lot of times, the rabbits that are prone to it will have difficulty on really any surface. Some say that wire floors cause sore hocks, but I haven't seen that to be the case. Usually sore hocks are related to weight or body structure. So it will be trial and error to see what works best for your bun.
