Is that behind his ears? Gus has something similar and the vet keeps looking for flea dirt. I told him at the last visit I knew he wanted it to be fleas. He politely laughed. Perish the thought!!
Anyway, the fur just isn’t growing back right and people at the vet keep looking at it and then moving on because they can’t find anything. The vet thinks it’s growing back, but I’m not convinced. But he’s way smarter than I am.
So, sorry, not help here, though I’ll be curious to hear how it does.

honestly that looks like normal regrowth under shedding. the new fur is always going to feel thicker because it’s not going to flex like the longer fur. i cant speak for the roughness because i can’t see it, but if its an area he frequently scratches, then that could certainly have made a starter spot for shedding as well as give him a possible scab if he did it too roughly

So, LHM, we need to figure on, like 3-4 months for it to regrow?
I guess I should add that my Gus was recently found to have a roaring ear infection. perhaps he’s been scratching it and not letting it heal?

I’m with LHM, especially since it seems to match the fur color but darker. Marlee’s fur is white at the base but orange as it extends outward. A few months ago I found a few small bad spots and just knew it was mites. When I got a magnifying glass on it, it looked like darkish brown-orange very short stiffer thick fur with the spots varying from dime size to nickle size, buried in a ring of white fur of her undercoat. Took her to the vet to find that it was normal fur regrowth — new growth can start out darker than the regular fur color.

Another vote for it being regrowth. When the new fur is dark, it can give the skin a bluish tinge before it comes through too.

Some rabbits will get dry skin and some flakiness. But has your vet checked for fur mite in the past?

Wooly has this short jet black stripe going right down the middle of his back right now. It’s so funny.