whiter hair

Question
I have a westie and his bottom os yellow due to constantely pee in her crate. How can I make her hair whiter.
Thanks

Answer
Dogs usually don't pee in their crate, or at least they aren't supposed to.  You should ultimately try to fix that problem.  To whiten her hair there are many different products on the market that you can shampoo her with.  Usually they are blue or purple.  Also, some people use peroxide but you'd need to be very careful to not get in in her face.  Hair stained by pee is very difficult to fix, so your best bet is prevention.