Yes, double knit makes great utility quilts. Cut it in larger squares, maybe 8 to 10, and tie or tack it. Do not use knit for the backing unless you are just laying it flat on a table or floor to tie. It will stretch way out of shape if you put it in any kind of frame. (Ask me how I know!) Flannel or other woven fabric that you don't know what to do with make great backs for a knit top. Not sure that I would use it with any animal that could catch it's claws in the knit.
Great floor quilts for babies (since knits are often brightly colored) or picnic quilts. Nice to keep in the trunk for those unexpected times when you need something to throw on the ground or snuggle under when outdoors.