It sounds like she may have peed and gotten litter or pee or poo stuck once she was wet. It happens, but sometimes they can’t quite reach every place to clean themselves once it’s dried. It can mask a problem (like if she isn’t urinating properly, or has an illness or can’t get into the litter pan.) I would clean her in that area and see if it comes back later in the day.

1. To clean her, start by holding her and taking a warm, damp soft washcloth and wiping the area to free it of the caked stuff. Only use a drop of unscented soap, or a baby shampoo. Do not submerge her in a bath, and never wash her head/face/ears area.

2. If that didn’t do it, take some plain corn starch – the kind they sell in grocery stores for cooking – and dust the soiled area with it. It soaks up any pee. Gently try to comb or work the mattes out with your fingers or a brush. Don’t pull the fur out of her skin. Stop if it isn’t coming loose. Let her try to remove it with the help of the corn starch for a few minutes next, in case she can get it clean.

3. If it still isn’t coming clean, you can run about an inch of warm water in the tub, set her in it, hold her firmly (she’ll try to jump out) and wash the area with your other hand. Then put her iin a towel and blow dry her from a distance. She’ll clean and dry the rest. If you set her in the sink she risks falling when she jumps out, so tub is awkward but safer. A young bunny will squirm so you need to keep the bathroom door closed, and do this on the floor. You can use a litter or a dish pan for the butte bath instead of the tub if that’s easier to use on the floor.

Once it’s clean, watch for a reoccurance. Clean her litter pan out, put a couple of poos in it so she knows she goes there, and see if she returns to clean litter habits. If she gets clumped up again, take her to the vet.

Yes, a white one shows the dirt more. Samantha is all white with just gray accents and spots, so she’s really, really clean too. I think the white ones ultimately groom themselves quite well.