non-drinking rabbit - high bilirubin

Question
Me again, with the non-drinking rabbit (8 weeks now).  In the last answer you said go ahead with abdominal radiographs, and also asked how her respiration was.  That was interesting, because I have noticed some weird snorting noises from her, both when turning around to groom and when eating very wet things (like water-drenched lettuce and apple).  She also seemed to be short of breath after going up the stairs, and has had some very deep sighs.  So we did radiographs of her abdomen, lungs, and head.  Abdomen showed everything fine, head did too -- clear sinuses and teeth roots and occlusion looked fine too. The vet said he normally wouldn't read dental xrays from an unanesthetized rabbit but these were crystal clear and she hadn't moved a bit (good bunny!).  The side view of the lungs seemed to show something obscuring the heart, so he did a frontal, which showed the lungs clear. He pointed out the kidneys to me, which were barely distinguishable to me in the white mass of her belly, but he said they looked fine too.

The one thing that stood out was in the urinalysis (done with sedimentation this time).  Specific gravity was a bit lower than last time, but not out of normal range.  Everything else was normal but bilirubin was very high. He had a +, ++, and +++ on his chart and had circled the +++.  Any ideas of what could be causing this?  He said it was related to liver, and I mentioned to you that the blood tests a month ago showed the alk phos to be high (though that one was after 4 days of metacam--she hasn't had anything since).  We put some new carpet in their room two weeks ago, and even though we let it air out in the garage for months, it still smells of whatever chemicals new carpet smells of.  She has access to other rooms, so is not in there much.  But could this be causing the high bilirubin?  

We're still wetting greens and giving 125 cc of subQ fluids every 5-6 days and she seems to be doing fine on that.  Meanwhile I have heard from someone online who had a bunny who didn't drink for TWO YEARS, then started drinking again after being bonded with a female.  Mine lost a close companion a year ago, and has some contact with a new  bonded pair through a fence, but can't really interact with them much. Could it just be that she's pining?!  But she still eats with such gusto....Bunnies are so complicated!

Petra  

Answer
Dear Petra,

Elevated bilirubin usually signifies some type of problem with the liver, but just *how* high is high?  Some individuals have idiosyncratically elevated levels relative to the rest of the population, and it's not a problem.

The shadow over the heart is a possible concern, though.  A thymoma (enlarged thymus gland) can cause pressure on the lungs and result in labored breathing.  If it enlarges to dangerous levels, it can be life-threatening.

I know of some people who have had their bunnys' thymomas treated with radiation therapy and corticosteroids, and if your bunny does have a thymoma, this could be something to consider.

But high bilirubin might also indicate a chronic infection, and that means maybe there is a cryptic abscess somewhere in the body (perhaps in the thorax?).  

At the moment, if bun is acting normal, I'd just stay the course and keep monitoring the situation every few months.  And no, it wouldn't hurt to consider letting her bond with a new partner.  The healing power of love should never be underestimated!

Hope this helps, though most of this is still mysterious!

Dana