my bullmastiffs have never ever gotten past chucking the bedding out. I dont know anyone that has sorted that one out .I even nailed mats to a pallet and put them in their houses , lasted two days and then they ripped them off and chucked them out as well. so I bought the extra large plastic beds and they are happy enough with those. I have a heat lamp over each bed . now and thenI pop an old bath towel or sheet in to see if they have stopped no way . So I wish you luck .

mari