The worst that ever happened to one of my quilts is gross...if you're squeamish stop reading.
I left a sandwiched quilt on my quilting table, ready to do some more quilting the next day. It was was a quilt for my daughter. One of my cats jumped up and vomited on the quilt...not just once. I couldn't wash it at that point. I had to finish quilting it enough that it would hold together through the wash. I finished it using rubber gloves and set the world speed record for straight line quilting.
Now when I'm finished for the day I cover my work with plastic sheets.