Unknown skin condition--vets are stumped

[heatherbasmagy]

My buns and I have been dealing with some unknown skin condition since May of this year. After about $2,000 worth of vet visits and diagnostics, there is no explanation, and their skin has gotten worse. I know it's a long shot, but I just wanted to share their story in the event that anyone else has dealt with something similar, or has any advice.

In May we noticed some small bumps on my 5 year-old Holland Lop, Harper. I immediately took him to my local vet that sees exotics. We quickly noticed that where it looked like he was molting there were bumps that were more like flaky scabs. He also had a few open sores. The vet did a regular exam and everything appeared normal aside from the skin condition. Did skin scrapes and did not see any mites. He suggested we try an antibiotic and a topical solution (Trimethaprim and Chlorohexadine) for two weeks and shaved his hair where it was coming out. After no improvement, the vet suggested we go the biopsy route. He did bloodwork which was all normal, and the next day, when brushing out my other bun, Delilah (who is probably 7 or 8), I noticed the same scabby skin on her, but not as severe. (She's a mini rex so it was harder to tell since her fur is so densely packed). Both of them have alopecia where this is occuring. Delilah's fur has grown back in older affected areas, but Harper's has not, and continues to flake.

Called the vet, he wanted to see Delilah right away, and put biopsy on the back burner since it was both of them dealing with this issue. We figured it might be something environmental. Took additional skin scrapes from Delilah, and again nothing, so he took a sample to create a ringworm culture. They were put on an antifungal for one month.

After the month passed, they were still experiencing the condition, and Harper definitely got worse. Nothing grew in the culture. I reached out to a friend in vet school and she reccommended me an exotics specialist. Got them an appointment for a week later.

Took them there, they both got full physical exams, everything was normal. Vet suggested we try Revolution which treats mites and other parasites, even though the skin scrapes did not identify any (this vet did their own scrapes as well). Rechecked after 2 weeks. Because of how severe it was on Harper, it was difficult to see if any progress was occuring, so we continued for four doses of Revolution. Rechecked again and the vet was still unsure, but noticed that the flakiness was coming off easily, and the skin looked healthy beneath it. She scraped most of the major flakiness off of Harper and wanted to see if it would improve on its own, so recheck in a week.
Well, the flakiness came right back. Took them back and the vet legitimately said she was at a loss. All the vets in the practice got together for a round table trying to come up with an answer, she scowered through all the existing literature, and nothing. Said she was really surprised it's not mites because it looks exactly like it. She suggested biopsy, but at this point I am out a ton of money (would be an additional $1k for the biopsy), and honestly I have put these buns through so much with all these visits that they now don't like me anymore. I also don't want to put them under anesthesia as that obviously comes with drawbacks, and the fact that they both have it leads me to believe it is something environmental, and a biopsy is not going to give us any more answers. I have switched the room they are in, deep cleaned, bought them all new toys, new hay, new food. And I'm still dealing with this.

At the last vet visit she did some deeper scrapes because maybe the mites were burrowing, but still nothing. We also sent some of the skin off to a lab to test for ringworm and the results came back definitively negative. At this point I am just ready to throw in the towel and let them live crusty. They are acting completely normal otherwise. But I just wanted to put this out there on the off chance that someone else has been in the same situation, and also just to vent because ****, I am exhausted.

photos are out of order but first is today (August 17th), second is July after 2 rounds of Revolution, third is today, fourth is two weeks ago when the vet scraped the skin, fifth and sixth are after 1 month of antifungal (end of June), and seventh is the initial vet visit in May.

 

[JBun]

It does very much look like sarcoptes mange, but if it was, I would expect to see improvement with the Revolution. Ivermectin is another rabbit safe (for most rabbits) antiparasitic to try if mange is still suspected at all.

But ruling out mange as the cause, the other two skin conditions in rabbits that have a similar appearance, are treponematosis (rabbit syphilis) and sebaceous adenitis. Especially if the condition doesn't cause excessive itching like would happen with a case of burrowing mites.

Medirabbit: treponematosis

Medirabbit: atypical rabbit syphilis

https://wabbitwiki.com/wiki/Rabbit_syphilis
Medirabbit: sebaceous adenitis

https://wabbitwiki.com/wiki/Sebaceous_adenitis
Treponematosis typically starts around the genitals, eyes, nose, and mouth, so it would be very unusual to manifest on the back, though it may still be a possibility And it is contagious, so can account for this skin condition affecting your other rabbit as well. Though if both rabbits have the scaling and fur loss on the back area, I would think it very unlikely for rabbit syphilis to affect both rabbits in this way.

But if it happens to end up being this, it's fairly easily treated with a series of penicillin injections, or I think azithromycin can also be used. There is always some risk with antibiotics dangerously disrupting gut microflora in rabbits, but those two antibiotics are generally considered safe for rabbits, though penicillin is only generally considered safe when given by injection.

Medirabbit: safe antibiotics

Sebaceous adenitis is another possibility. In fact I had an older bun that started to have non itchy scaly flaky skin along his back and hindquarters, that I initially thought was due to mites. So he was treated with Ivermectin, but the problem persisted. He also had some other symptoms occur like more labored breathing and weight loss. He then had a scan and it was found that he actually had a thymoma and the skin condition was thymoma related sebaceous adenitis.

Sebaceous adenitis isn't always related to thymoma, it's just something that can commonly occur with it. So it's possible your rabbits could have this independently from thymoma, and in fact likely to not be associated when both rabbits have the skin condition. It's not contagious, so both rabbits having this would likely mean there's some other common environmental or dietary problem causing it.

I don't know if your vets already tested for these possibilities and ruled them out, but these would be what I would suspect with crusting of the skin and fur loss, if mites is ruled out.