As any librarian knows, weeding the library collection, or pulling books off the shelves that are nasty, outdated, missing pages, etc. is something that every library must do to offer patrons the best information possible. Here at my library, we know it's something that needs to be done but we don't always have time to do it. Luckily, we have the canine program...
One day a handler came to the library with a new dog she was training. They were over in the 600's (we still use Dewey) and I wasn't really paying attention until I heard "AUUUUGHT!!!! NO! BAD!" I looked over and the trainer was frantically trying to clean something up with a towel. I went over to investigate and it turned out, her dog had peed all over an entire row of books on the bottom shelf. Because I have seen it all and nothing fazes me anymore, I asked the trainer if she needed to take the dog outside, and as she was exiting I called the clerks over, gave them gloves and had them bag up the pee books.
After we cleaned the shelves and carpet as best we could, I assessed the damages. 20 books had been affected, but miraculously, all but one should have been weeded anyway because they were fad diet books from the late 1990's.
The next time I saw that patron she said "I am so sorry about my dog, I am never bringing another dog to the library again." "No worries at all," I told her, "because your dog just completed a weeding project for us, and he's hired!"