I made this for my cat, I really didn't know if he would use it because he trutly believes he is human and doesn't need silly pet toys or paraphernalia. However, he loves it!
I used worsted weight yarn, 2 strands held together to make it thick enough I used a K hook as well.
Make a magic ring, and crochet 10 sc inside of it.
R1 ch1 2sc ,* sc, 2sc * *around* and join with a sl to the first sc.
Every row after this just copy R1, except each row add 1 more sc in between your stitches with 2sc's...so row 2 looks like this:
R2 ch1 2c,* sc, sc, 2sc* *around* and join with a sl to the first sc.
Any questions? Just ask!
Keep going until it is big enough for your pet. My cat is a big boy, and his rug is 16" in diameter.