I have two 50 pounders and they are not long enough, nor are the "tuck in flaps" long enough, after two jumps up on the furniture they are in total disarray.  I am constantly retucking and straightening them.  The material is sturdy enough, better than the last couch covers I bought which makes me happy but they are not practical for my needs.  They would be great for little dogs maybe 20 lbs or under but big dogs forget it.