Testicle infection?

Question
I've been working with rabbits for a number of years, and can usually solve any problems brought to me, but this one stumped me.  While grooming one of my rabbits today, a mini lop buck, I noticed that he had a couple of small white and silver colored lumps on one of his testicles.  They also seemed to be perfect half-spheres.  I've checked all my resources, but I cannot for the life of me figure out what it could be.  Aside from finding a way to give himself horrible hutch stains, nothing else seems to be wrong.  Any ideas?  Thanks!

Answer
Dear Liz,

Rabbit pus can be very pale, depending on what type of bacteria are causing the problem.  The pus is also very thick and cheese-like, so it won't run if the abscess is punctured.  The best option might be to get bun to the vet for a biopsy and culture and sensitivity test, if you think the lesions contain pus.  More information here:

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

And you can find a good rabbit vet via the list linked here:

www.rabbit.org/vets

Are the lesions smooth or rough?  Are they flat/disc-shaped or actual, rounded "lumps" in the testicles?  How big/small are they (in inches or mm)?  Have they changed in size or shape since you first noticed them?  How long have they been there (or how long since you first noticed them)?

If he's an older bunny (or even if he's not), he may have testicular cancer.  Sertoli cell cancer has characteristic lesions consisting of concentric rings, and these grow rather rapidly and noticeably.  If this is the problem, neutering will usually effect a permanent cure.

If you could take a picture, scan it and send it to me, I might be better able to guess what this might be.  

Hope this helps with some ideas, at least.  Please write back if you think I can be of more help.

Dana