dirty/stained bunny bottom

Question
We have had our bunny, Steve, for about 7 months.  My boyfriend found him outside at his work and brought him home, we believe he was about 8 weeks at the time.  I say "he" but we aren't sure if he is a boy or girl.He is kept indoors(in his hutch when we aren't home and he has free reign of the livingroom when we are home).He is litter box trained and the box is kept outside his hutch, he will do his thing in his hutch when he has too but prefers the box.The problem is he is an all white bunny but always has a brown bottom and crotch.We have bathed his bottom a few times, which he doesn't mind at all, and it does help clean up the mess but doesn't get rid of it completely.He appears to be healthy and his poop looks normal.He doesn't smell at all and there is no actual poop stuck to him, so I'm not sure if it is a poop problem, urine problem or maybe a sex gland problem.We don't have much money for a vet otherwise we would have taken him long ago and had him fixed, etc.I'm hoping its more of a cosmetic thing since he does like to sit in his box and maybe it is staining his fur, but if it is something serious we would certainly take him to the vet.He is very social, loves to go camping and to the park and doesn't appear to be bothered by his stained bottom.He always has timothy hay, alfalfa, pellets and water avail to him.Can you give me some advise on what the most probably cause could be and the best way to remedy it?  

Answer
Dear Maureen,

A white bunny will often have yellowish stains on the bottoms of his feet, and that's normal.  Sometimes if s/he dribbles urine, the fur around the vent can become stained, especially if s/he's not spayed/neutered, and is spraying.  Please see:

www.bio.miami.edu/hare/spay.html

and in case it might be urine leakage, please read:

www.bio.miami.edu/hare/urinary.html

If he has a messy bottom, please also see:

www.bio.miami.edu/hare/poop.html

and

www.bio.miami.edu/hare/buttbath.html

But if he's just a bit yellowish on areas where he stands/sits, it's probably just standard staining,  and nothing more than a cosmetic problem.

You can find a good rabbit vet here, in case you need one:

www.rabbit.org/vets

Hope that helps!
Dana