Regurgitation?

[Bogertophis]

And it’s ok that the reptile is taking rats as his usual diet. This is a health issue and it’s a rehabilitative approach that’s being taken to get the treatment into the animal that’s needed. It’s a very short term dietary change and probably a one time change and monitor the animal as the OP considers switching to a smaller prey item with less / no fur.

I was just thinking that with some BPs, they get "stuck" on the prey they prefer, so it can be risky to offer mice if they've been eating rats, & assuming the owner wants to keep them on rats.

If it was a rat snake, or one of many other kinds of snakes, I wouldn't think twice about offering a different kind of hairless rodent, but some BPs will be goofy about it.

Another option: The OP could always shave the rat...you wouldn't have to get all the fur off, just some would likely help.