How to remove the smell of cat urine from your books

A "friend" asked for my advice on the topic above. It is not only a pile of incunables that makes an enticing cat bed. Any books ill-advisedly left in a cardboard box -- after a move, for instance -- can suggest to cats that there is a new lavatory arrangement in their new home. Unpack those books now! (Then smear your friend's paws with butter. Not only will this reward him for his patience during a trying time, it will establish your cat in his new human-built environment.)

If it's too late, here is the advice of a librarian, which I republish for the benefit of those who need it. I don't mind myself.

But if you don't get the smell out, then you will have de facto a new litter arrangement: on the floor where the book lies, on the shelf, in amongst the shredded paper made by your resident recycler. Bog book not required -- there will be plenty to read for your literate furry friend while he does his business.

How to Get the Smell of Cat Pee [sic] out of Books -- Basic Instructions

It is best to be prepared.

(1) Open the books and sprinkle each page with baking soda. Be sure to cover all areas of the books, including the covers and bindings.

 (2) Place a table in the direct sun on a hot day. Stand the books on their ends, inside the plastic bags, with the cover and pages open to allow to maximum airflow inside the books. Place the thermometer inside the bag, near the opening, and seal the bag with a twist tie.
     
 (3) Allow the books to stand in the sun for two to three hours. Open the bag just enough to fit your hand inside to reach the thermometer. Do not open the bag more than necessary or you will allow too much heat to escape.

(4) Read the thermometer. Once the temperature reaches 140 degrees Fahrenheit the bacteria will be destroyed. {That is 60 C -- very hot.}

(5) Remove the books from the bag and brush off the baking soda with a clean dry cloth.

Glossed by Librarian with Cats 

Best practice - ziplock baggie with book and about half a cup of baking soda.

Try for one of those 2 gallon or "supersize" baggies; you want to be able to open the book while it's in the bag, without opening the bag itself.

Get the extra air out of the baggie (don't go crazy, just don't leave it too puffy with lots of air - smoothing it out with your hands is fine.)

Leave the book + soda in the baggie for a few days, and during those days, every time you walk by, shake up the baggie to get the soda all dusted about again. Open up the book and let the pages flip while the soda is all floating around - flip the pages through a few times per shaking session to really get the soda in contact with the individual pages and the insides of the hardcovers and into the crevices of the spine.

Aim for shake/flipping pages about 4 times a day, and at the end of each day, take out the book, discard the baking soda from the baggie, and put new soda in with the book again.

You're done when you can't smell cat pee anymore. (This could take a day, it could take a week. If it takes more than a week, it's usually a sign that you're not going to win this one.)

As a bonus round, if the book still smells a little "off" but not recognizable as cat pee, follow up the baking soda routine with a day in a baggie with a few dryer sheets. They'll absorb smell and slightly "perfume" the book, to mask a little bit more of the funk. 

Does the baking soda leave any marks or discoloration on the pages?   It won't discolor the pages, and if you have a laminated-cover (plastic-slick feeling) book cover it will be fine there also.

The only thing I can see you having trouble with is an older or cloth-bound book; you might get some lightening effect on the cloth if it is at all damp or wet.

Even then if it is light-colored, there won't be an issue.

Short Version - I would only worry about rich or dark-colored damp/wet cloth covers - everything else will be fine.

☜ A fifteenth-century scribe had no such good advice at hand, only curses and rude drawings.

As I have often said of my self,

cats have a natural affinity for the bookish arts.