I have 2 dogs - somewhat med sized. They both LOVE my quilts. I have one on my Futon in the quilt room and it takes all I have to keep an eye on them. They are good once they settle down, but they like to make "nests" with them and some of the seams have come undone. I don't mind too much - it was one of my firsts and I love that they love them.
Maybe do a smaller quilt - don't put too much time into it, and use bigger seam allowances. :)
I am thrilled when people think enough of my dogs to pick up a toy for them - your friend will be thrilled you make something comfy for them!! :)