l had to repair my dd'quilt that her puppy chewed holes in.l removed a whole section where the most damage occured, unstitching the front, trimming the batting, then cutting the backing so it had some seam allowance. l remade that top area with similar fabrics in squares cut to size & attatched seaming the usual way ( reaching through that large hole from back. l then basted in batting, and patched the back up, just top sewing it through all layers, and added appropriate quilting lines to go with what existed. Next, the smaller holes l patched as the others have already suggested.