I don't have a pet, but I often knit for people who do. A knitting group that I belong to had a request for snuggles to donate to animal shelters. This is my interpretation, a thick blanket to line a kennel.
I used rug yarn, doubled, and knit a garter stitch rectangle. Then I picked up stitches along all sides and knit in the round, increasing 2 stitches at each corner. After a couple of inches, I stopped increasing and knit a few more rows before binding off. You can see where I used up a lot of different colors. I don't think the animals will mind.