Calcium crystals or bladder sludge?

Question
I have a lovely, little (sort of) male, mini lop that I love dearly. I had wanted a rabbit for a long time & my husband got this one for me for my 50th b-day 3 years ago. He's a little over 3 years old and was neutered as soon as he was old enough, I think about 8 months, but I'm OLD so that's approximate. We live in northern California, north of Redding and it was not easy to find a vet who would neuter/treat him. Dr. Presleigh is about 40 miles away and though he says he's not a rabbit expert he has no qualms about contacting sources at UC Davis to help him.

About a year ago he diagnosed Bun with calcium crystals in his bladder. We had noticed a change in his bathroom habits and other things that told us to get him in there. He stayed for 3 days on medication and having his bladder expressed (?) manually. Dr. said diet and watching him very carefully might be enough. The only other option being surgery. After $400+ in vet bills so far I know we can't afford surgery and rabbits being somewhat fragile in those ways, he said it would be quite possible he wouldn't make it thru. He came home for more medicatio, a diet change eliminating, or trying to, all calcium and "force" feeding water sometimes. He seems to be doing pretty darn good right now, though I worry about the rubber bits he chews off the backs of throw rugs & door mats!

We started getting newspaper roll-ends because you can make a mountain out of crumbled paper and he loved to hide in there & come leaping out. They have played a more important role lately though. The paper makes it much easier for us to monitor his urine passing! I never thought we'd be so happy about his peeing anywhere and everywhere but hey, the wall-to-wall was old to begin with.

Cut to the chase -  he seems to be peeing plenty but the fur around his bottom is wet an awfully lot. Now that we are aware of it he gets "butt baths" which he's actually getting kinda sorta used to and my husband bought some electric animal trimmers so we can keep his butt shaved without the added trauma of a car ride all the way to the vets.

He gets no pellets anymore. Only greens (dandelion, collard, red romaine, Italian parsley, parsley, cilantro, carrots {can't find ones with tops anymore : ( }, snow peas, a little banana and apple are the only fruits he eats, rolled oats, which he loves, an occasional treat of a small amount of shredded wheat and of course Timothy hay to his stomachs content.

Is there anything we can do to improve his diet, considering his condition, or improve the condition of his damp bum? I think if the paper weren't there he would go in the litter more which wicks the moisture away from him better I'm sure? We use Eco-fresh litter which is a rolled or pelleted paper product (at aprox. $1 a pound I may start rolling some myself!)

He's always been a "free range house bun" (my husband has been retired since before we got Bun) and I'm not going to cage him up now because of a little posterior moisture.  Besides when I come home from work Bun gets way more  excited than my hubby ever has! Vinegar is very handy and doesn't smell that awful when you get used to it!?!

I've done quite a bit of reading on this calcium condition but any suggestions or tips would be very welcome.

Here's to his long life even with a damp butt~
       if only my husband had fuzzy cheeks, a velvety nose    
             and long, furry ears, we can skip the wet bum here!

Answer
Dear Victoria,

It's such a treat to get a note from someone who obviously adores her bunny so much!  And especially from someone who also realizes that there are more important things than having a spotless house. :)  We always have the ol' bleach mop going, too.

Okay, first the sludge.

Is the calcium residue in Bun's urine whitish/ivory colored and relatively chalky?  Or is it more the color of curry powder and the thick consistency of toothpaste?  The latter is true bladder sludge.  The former is normal, as all rabbits excrete calcium salts in their urine.  

If he's leaking urine, though, it's possible that he has sludge *and*/or a urinary tract infection.  Has his urine ever been cultured for signs of bacteria?  In some cases, sludge can promote infection, and it's believed that the reverse can be true, too.  It's wise to have a culture and sensitivity test done to be sure he doesn't have an infection that needs treatment. You can read more about this here:

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

and more about urinary tract problems here:

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

The most experienced rabbit vets I know are no longer convinced that dietary calcium is a contributing factor in sludge.  In fact, reducing dietary calcium to near zero could do more harm than good, if the problem is due to metabolic bone disease.  Such a disorder is probably genetic, and we do see it more often in purebreds (especially Holland Lops) than in hybrids.  If the problem is metabolic bone disease, then the reason for the sludge is not excess calcium in the diet, but rather an inability of the bunny to properly metabolize calcium in the system into bone.  It's also possible that Bun is simply losing bone mass due to this disorder, and could start to show signs of osteoporosis, so that's another thing to be vigilant for.

Weird as it sounds, a bunny with bladder sludge is also often more prone to molar problems.  As osteoporosis thins the already light bones of the skull, the molars can become very slightly loose in their sockets, causing them to move when bun chews.  Because rabbits' teeth grow continually, this can cause molar spurs to develop, which can be very painful.  A good rabbit vet will know how to find and file smooth these spurs.  You can read more here:

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

Keeping Bun's bum dry is a bit more of a challenge, but you're on the right track by regularly expressing his bladder.  This is *very* important to do if he produces a lot of sludge, since in some (rare) cases, the bladder can become impacted with sludge, a condition that can be life-threatening.

To prevent this, be sure Bun gets lots of fluids (subQ occasionally, if the vet thinks it necessary).  When you express his bladder, make sure it's quite full, and before gently squeezing (I'm sure your vet has shown you how to do this, but if not, be sure to learn soon.), *agitate* the bladder as much as possible to suspend the sludge in the urine.  Positioning the bunny in various ways (on his back, upright, etc.) before expressing and after agitating can also help get the sludge into the liquid portion of the urine so it can more easily be expressed.

Once the bladder is relatively free of sludge, it's less likely to "leak," but if the leaking continues, then it's *definitely* time to get him checked for a urinary tract infection, since that, too, can cause leakage.

You can keep his bum dry and clean in the meantime with the following butt bath procedure:

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

I hope this helps! Please write back if you have any other questions.

Dana