A few years ago I had a cat who squirted every tiny hole he could find in my computer. Eventually, after God only knows how many repair bills, I found that a plastic cover worked wonders, also kept out dust. My daughter's present cat likes to piddle on her keyboard, the top of her tv, and the computer monitor. Plastic covering would help her, too, but will she use it? No. She bought a new keyboard last week.
They used to make keyboard trojans you could type through. It never seemed the same to me though.