I don’t like diatomaceous earth. The critters actually have to walk through it in order for it to work, and it is toxic to breath in. So if you were to work it into your rabbits fur, the only way to get the fleas to walk through it, then you and the rabbits would be breathing it in. If you do use it – you want to be wearing a dust mask so you don’t breath it in. It comes in two forms – crystalline and amorphous. Mostly it is amorphous which are larger particles and easier to breath out. But All DT has some degree of crystalline form, which gets trapped in the lung tissue. Long term exposure causes silicosis, a non-cancerous lung-tissue-scarring disease.
It’s probably a better idea to just take them for a checkup, get them dosed, keep them quarantined for a month, clean your pet areas, and check yoru other animals for fleas. But if they don’t have fleas, then you don’t have anything to worry about. To check them, spotting a flea is obvious. But another way is to look for flea poops. It’s easier to see on white hair rabbits…