A medieval cat's paw prints are all over a 15th-century manuscript. However, this particular scribe got off lucky considering that another scribe writing in 1420 had his manuscript doused in cat urine. The page was not salvageable. Interestingly enough, he chose not to rip it out of his manuscript but kept it in and drew a crude picture of the cat and wrote the following complaint in Latin:
"Hic non defectus est, sed cattus minxit desuper nocte quadam. Confundatur pessimus cattus qui minxit super librum istum in nocte Daventrie, et consimiliter omnes alii propter illum. Et cavendum valde ne permittantur libri aperti per noctem ubi cattie venire possunt."
Here's the rough translation:
"Here is nothing missing, but a cat urinated on this during a certain night. Cursed be the pesky cat that urinated over this book during the night in Deventer, and because of it, many others [other cats] too. And beware well not to leave open books at night where cats can come."