Upholstery thread is pretty much the strongest thread you can buy. Usually the fabric will rot/fail before the thread does.

I also have to occasionally do sewing 'surgery' on my sheltie's stuffy toy when she goes overboard in playing with it. She waits uneasily for me to bring it back every time!

If you have a larger needle and it's not hard to use... Use it.. but for thread, Nothing works so well as dental floss!! I've used it for so many things... if you use a hidden stitch, it don't show, and it won't ever break... You can't break it with your hands... and it holds tight. It's waxed and slides thru with ease