What causes a hairless, scab-like patch under my bunny's chin?
Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry to hear about Donut. It appears that she may have some dermatitis (inflammation of her chin) and resulting infection. With chin dermatitis, oftentimes it is caused by drooling from some form of dental disease. It would probably be warranted for your veterinarian to take a good look at the teeth under anesthesia/sedation. Most likely regardless of the cause there is a bacterial infection occurring now. I would recommend culturing the lesion. If antibiotics are indicated, many pharmacies do flavoring which can really help with oral compliance.
Also, I would try to keep the lesion dry with an astringent or manually just keeping the area dry with a clean cloth. Overall a good exam and history (any new changes in bedding, food area, detergents, caging), with some other diagnostics if possible including x-rays, blood work and oral exam will probably be helpful toward determining the underlying cause. This could be very easy to treat especially if due to misalignment of her teeth. Good luck with Donut.
Updated on September 23rd, 2025