Not to problematic levels in my experience. When I was boarding, my donkey would lay down in her shavings-filled stall with them on. Anything that got in there would mostly fall out the bottom. A few would get stuck in her long donkey hair, but since the boots fit so loosely, there wasn’t any issue with rubs or irritation. And let me tell you, I don’t know what that donkey did in her stall when she was sleeping. She must have tried to burrow down into the shavings when she slept because she would be COVERED head to toe. :lol:
Now that the horses are home, the sometimes lay down in their straw stalls with them on. That’s not an issue, either.