I remember a Chwast cartoon from years back, something about either TV or books for cats. One was a ball of wool, and entitled, you guessed it, "Yarn".
But wait, now your cat can do yarn and be yarn too, if you go to VIP Fibers Inc. in Morgan Hill, CA. They specialize in spinning yarn from the silky undercoats of your pets, and your pup too can get in on this fiber action.
Comb your pet, send your fur, get your yarn. And why not? VIP assures us that long ago a garment spun of dog hair was good luck for the wearer. But don't knit your pet fur into socks: socks need to be stretchy, and pet fur is short and hasn't the crimp that sheep and goat wool do. But dog yarn is 80% warmer than ordinary wool, and traces of it have been found in textiles from prehistoric Scandinavia and the Navajo Indians. Nobody's said anything about the relative warmth of cat yarn, but you'd think it would be similar.
Go get your skein on here.