Our big goofy lab and two long hair cats sleep on every quilt in the house. They hold up just fine. The way I see it, the quilts are made to be used and loved, washing frequently just helps to age them, and if they wear out, then I am justified in making more.
I agree that keeping the pet nails trimmed is helpful. And we brush/bathe/groom our pets frequently to minimize the need to wash the bedding constantly.
RST
We have 2 Shibas and a kitty and this is my practice too....they appreciate quilts so much, I make them to cover the furniture, wash them, 'de-hair' them when the dogs go through shedding, and rotate them for different seasons. The quilts too special for pets are hung as wallhangings or on quilt racks. Quilts hold up through many washings (I use a Shout Color Catcher for a time when first being washed). And, as you said, when the quilts get old, they'll be replaced! And, I bathe the dogs every 4-6 weeks or so and keep their nails trimmed too.