Probably a bit late for tomorrow unless you've got a garden centre or pet shop near you which sells vetbed, but can you get hold of a piece of vetbed (I think original is best but there are other cheaper brands around). Vetbed is soft and fluffy but it draws any wetness to the underside, a bit like a nappy I guess, so any animal wetting the carrier stays dry. I have no idea how it works but I use it in carriers and in the rabbit sheds and it's brilliant stuff!