Have you put the hay in his box? I know my bun has an easier tiem with litter box if she has her hay to munch on in there.

Welcome Julia
Can you tell us a bit more about Downy? How old is he and how long have you had him? Is he neutered? What sort of litter box do you use? etc Loss of litter habits can be due to health issue, litter too dirty, litter too clean, new animal in house, bunny puberty and many other little things.  The more info you can give the more suggestions we can give.
Bluegrass is fine for bunnies.

Hi, Julia. Welcome.

Until you said he slept in his litter box, I was actually going to ask if it was too small. It may be an uncomfortable shape. (My bunny does better now with a rectangle instead of a corner box as she’s gotten bigger.)

The also may prefer one type of litter over another.
But first, try to get him to associate the box with going in it. When he urinates outside the box, wipe it up with a little paper towel, and put the soiled towel right back in the box. Scoop up all the poos into the box as well. Then put the hay in one end, so he smells where to go in one side and can munch hay while there. If it’s too clean (completely fresh litter at first) they don’t recognize it as their spot for going.
And he may just want it moved over slightly. They tend to pick a favorite corner in their cage, so you need to put the pan under them.
If you post some pictures (we LOVE pix) we can see to help.

It may just be that he doesn’t like the kind of litter. I know my Monkey likes the soft stuff, and wont use pellet like litter. Fussy little thing.

Hi Julia, welcome! If your bun is 7-8 months old, he’s hit puberty. So the problems with the litter box might be because he’s territorially marking. It’s good that you’re planning to get him neutered. Until then, I’d try the suggestions others gave, moving the litter box to a place he likes better, trying different litters.

Are they just poops outside the box, or is he peeing outside the box too? I’ve been told that with some rabbits, if they consistently urinate in the box, and just leave a few poops outside, the rabbit is considered litter trained. It really depends on the rabbit’s habits and preferences though. Leroy has never pooped outside of his box (except when he was territorially pooping when he first met my boyfriend – Leroy is a jealous bun!)

i would have to agree with barbie. it sounds like he’s marking his territory!

He might just not liek a box in his cage. Now that my bun doesnt get closed up in her cage at night, she doesnt use her cage box either. Just the one in her pen

So it’s a poop pile next to his box that’s outside of his cage? Sounds like he’s having an “issue” with box. Maybe try a larger one? As to the one in his cage, he must view it as a bed so won’t soil it too much.

“I haven’t seen him pee outside of the box, but he very well could be. My carpets are very dark so it’s hard to tell, but I think for the most part he pees in the box.” … Walk around barefoot… you’ll find out!

Also, the second litter box could help; some buns just like haveing one for their bed and one for their potty.  Instead of a second litter box in his cage (becasue Leroy’s always been very good about using the toilet and I didn’t want to mess that up) I bought a smallish faux sheepskin cat bed for him.  He LOVES it, does flops in it all the time, and that’s where he sleeps, when he’s in his cage.  I just bought him another one for his corner of the living room, like his own personal couch!