Great advice Becky, thats exactly what I would have reccommended.
But do watch your rat when giving ivermectin, I had one I gave it to, to treat mites that would not go away no matter what..and he ended up with neuro problems because of it. I had him on it for 14 days (per vet instructions), and I cannot remember the dose, but I do know it was low because he was a bit uncomfortable using it in rodents unless they had severe issues with mites re-occurring, and he did tell me it *could* cause neuro problems as an after effect depending on how he reacts to it. I have also used ivermectin in a rescue rat and a friends pet rats without any effects at al, so, for my guy, he obviously did not react well to it. All in all, ivermectin is a highly effective way to treat mites.