Swollen nipple/ lump

Question
Yesterday I was rubbing my dwarf bunny's tummy and noticed that one of her nipples is swollen with a lump behind it.  There is no discoloration of her nipples, but their skin is dry and crusty, and there is a tiny dark dot on the end of her swollen nipple.  She is five years old and has never been fixed or bred.  She lives in a cage with wood chip bedding.  We recently adopted a kitten, but other than that there have been no changes in her surroundings.  Can you please help me figure out what's going on?  Thanks!

Answer
Dear Laura,

Signs like this definitely warrant a trip to an experienced rabbit vet.  Unspayed, unbred female rabbits have a very high risk of uterine adenocarcinoma (cancer) and mammary tumors, and this could be an early mammary tumor.  I would not let it get any bigger before getting her to the vet to find out.

If the lesion is still small, it's possible that surgical removal *and* a spay will solve this problem for good.  Mammary tumors are most often estrogen sensitive, and unless she is also spayed, her chance of the cancer recurrence will be pretty high.  

You can use the list linked here to find a good rabbit vet:

www.rabbit.org/vets

but I'd get her there ASAP for examination and scheduling of a spay, even if the mammary problem isn't a cancer.  At her age, she's a little ticking uterine cancer bomb, and spaying will improve her overall health and longevity.

I hope this helps.

Dana