Skin disease/infection. Vets stumped

Question
I've got a very poorly rabbit who has stumped 3 different vets and online rabbit communites, maybe you can help diagnose this problem.

I've attached some links to pictures of the rabbits skin disease.

http://myrabbitbunnies.com/images/pika2.jpg

http://myrabbitbunnies.com/images/pika4.jpg


The rabbit has had this skin disease for about a year (slowly getting worse, starting underneath her and now moving onto her back), has seen 3 different vets (first two were clueless, 3rd new vet seems to be trying different treatments but is stumped).

Shes been on 3 different types of antibiotics (beytryll, deposilin and septrin paediatric) with no success in clearing it. What happens is her skin will go very red and very hot (even though it's 15c outside approx) the next day it'll go cracked and extreamly dry then the flakes turn yellow and slowly fall off after a week leaving soft healthy skin if we are lucky. The cycle then repeats itself.

Shes happy running around, eating and drinking LOADS but has lost some weight. A steroid injection helps pick her back up but the vets wont give it to her on a weekly basis for obvious reasons.

She has had skin biopsys that came back clear and is now booked in to have a blood test and an xray to find out what it is. The skin under her fur is fine, it's only the exposed skin mainly.

She is clear of mites and had panemic injections the last few weeks. We put bunny friendly aloevera cream on every day but it doesnt seem to do much.

Finally she is limping on her back foot as she has a large swelling that wont go down even with 4 weeks of antibiotics.

Everyone we speak to has no idea what it could be.

(We've (the vets) determined it's 99% unlikely to be an allergy, mites, ringworm, mange etc)

Thanks for your time and help.

Answer
Dear Marc,

We have a rabbit (also black, interestingly enough) who has a similar condition and the progression is also as you describe.  It has gotten quite bad lately, and the people who adopted him from us have brought him back to be hospitalized with us because they just couldn't handle it.

One strong possibility is sebaceous adenitis.  This is an auto-immune disorder, and if this is the primary culprit, then only corticosteroids will keep it at bay.  

I have a suspicion that there may be a fungal copathogen causing Bartok's problems, so we are now treating him with two different antibiotics (which seem to be helping secondary bacterial infection that was horrific, but is now merely awful), and are also treating him topically with clotrimazole cream, which does seem to help.  It's interesting to note that while lime-sulfur dip, nizoral shampoo, and various other types of fungistatic medications didn't work, the clotrimazole seems to be helping--at least so far.

I wish I had better news for you. But if your bunny has what Bartok has, then we're both in for a lot of work with no clear results. :(

If I find something that works, I'll let you know.  Hope you will do likewise!  

Dana