I believe bald hocks can happen naturally in old rabbits, but red and scabby hocks sounds much more like sore hocks, especially if they’ve bled before.
If it is sore hocks, a couple of things can contribute to it:
1) Wire floors or any uneven floors (even too soft floors): Wire floors are usually the culprit, but constantly being on really plush surfaces can also cause it and perpetuate sore hocks. Imagine as a human constantly walking on both wire flooring and a bed with lots of pillows. In both circumstances, there’s a lot of weird weight shifting. Are most of the surfaces she’s on pretty solid, rather than very squishy? Unsure of what the mats are like.
2) Weight: Rabbits that are overweight can more easily develop sore hocks because of the excessive weight. Has Sansa been overweight for a while?
3) Lack of movement: Sitting for long periods of time, rather than lounging or running around will increase time spent on the hocks, making them sore. How is her physical activity levels, and how does she usually lounge?
…. You can think of rabbit hocks being exactly like human elbows. There’s literally just one layer of skin/hair, then direct contact with the bone. There’s no fat in between. Just like how easily elbow weight can irritate us, that can happen to rabbits. A rabbits fur density can affect this (someone once told me angoras are less susceptible because their hocks are very pillowy with the fur?). If she already had bare hocks, it may not be you have a set up that gave her sore hocks, but since her hocks never got to heal, they just keep getting irritated.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.