story identification - Book about a man transported to a desert world. Buildings are made from salt and urine might be eliminated as solids

Kind of a longshot, because I have fuzzy memories of this at best, really only the beginning of it. A man from our Earth somehow gets transported to a desert world where buildings are made out of salt because there's so little water. He thinks he's entirely human until he tries to urinate and finds that he excretes crystals instead, all water being retained in his body. I want to say that he compares himself to a kangaroo rat at that point.

I read this in middle school or so, so it's late 80s at the least, and probably older. I read it as a paperback in my brother's sci-fi/fantasy collection.

Answer

That's the first book in the Gandalara Cycle, The Steel of Raithskar.

The main character is on a cruise ship, talking to a lovely young lady, until he sees a meteor coming at them. The next thing he knows, he wakes in a desert. He seems human enough, but later discovers very prominent canines, and that his body is adapted to conserve water. (He first notices when he urinates and it almost instantly turns to crystals.)

Most people don't live in salt buildings, but there is a group that maintains oasis type camps that do; they are able to acquire water in the middle of the desert through means that our Hero comes to understand in one of the later books.