Sometimes they just make the dog sick. I came home one day to find one of my dogs had broken into the Almond Roca Christmas gift that was in a bag on the floor. All sorts of tinfoil wrappings all over the floor when I came home.
I found out it was Gromit later that evening when he left a big nut encrusted chocolaty puddle on my brother's hardwood (thankfully) floor that evening for Christmas.