Few more details: if possible, I'd like to do an introduction in the cage before its all made up with fleece, with all its proper toys and food and hay, administer it, and if it goes well take them out and prepare the cage with fleece and new toys and stuff. In a cage neither guinea pig has been in or seen before.
Is this at all possible or does it have to be in a truly neutral territory?
Is this at all possible or does it have to be in a truly neutral territory?