I have ''made'' pet beds from the thick foam that you buy at Joanns. Measure the space and have them cut it in the store, then use a heavy duck type cloth and make a pillowcase type cover for it....make several as they need to be washed often. Or, you can buy a nice baby mattress ( if you have an older dog who has wet accidents ) and make the same type of pillowcase cover. The cost will be about the same as the foam but way less than the ''fancy'' beds from the pet store!!!!