Urgent - Ive already been to the vet but dont have a proper explanation for hind leg weakness and continued incontinence!

Question
Dear Dana!

I live in Denmark where there's a lack of rabbit savvy vets so I turn to you hoping that you can be of assistance.

My neutered rabbit who will be 7 this summer has suffered from incontinence and hind leg weakness for a couple of months. X-rays showed a severe case of bladder sludge which has been treated with Baytril and Metacam. Also, I went to the health food store where they suggested an all-natural product called Resium which is supposed to be very effective when it comes to kidney-, gall-, and bladder stones in humans. After having consulted my vet, we agreed that it wouldn't do any harm to give 1 ml. per day to a 2.0 kg. rabbit. As his water intake has already increased during these past couple of months and I make sure his veggies are wet, we didn't find subcutaneous fluids necessary. After one week on these meds, the vet said that his bladder was almost half the size it was before and not nearly as tense, so we went home with more Baytril and I continued with the Resium for a few more days.

He's going back for a check-up on Tuesday and what really worries me is that his incontinence hasn't improved at all and that his hind leg weakness seems to be getting worse. His blood test came back normal, his kidneys are fine, and from feeling his legs the vet doesn't suspect arthritis. I suppose another x-ray focusing on his legs would be a good idea though. His appetite is as good as ever(he's bonded with two other bunnies and he's always the first to "attack" the food bowl when their dinner is served) and he doesn't seem to be in pain although he's a bit more quiet than he used to be. Also, he's obviously lost weight.   

I would very much like to know what you think the vet should be looking for and what kind of further tests should be done to give an exact diagnosis. I know that paresis is quite common in older rabbits but on the other hand I think he's a bit too young to be suffering from that. Besides, do you suggest other kinds of meds for the bladder sludge and would it help his leg weakness to start him on a non-steroidal anti-inflammatory drug?

I really hope you can help as I just want my little guy to feel better and the vet's lack of knowledge about rabbit medicine is quite frustrating. Thank you so much in advance!

Birgitte Dahl Jensen

Answer
Dear Birgitte,

Has the vet considered the possible contribution of Encephalitozoon cuniculi?  This protist parasite resides in the central nervous system and kidneys, and can cause damage to both.  Hind limb paresis and urinary tract problems are some of the first signs of infection, and problems usually start to show up when a rabbit is five or older, even if the bun has harbored the parasite since a very young age.  (This is very common.)

The parasite can be treated with ponazuril (toltrazuril sulfate) and/or fenbendazole (NOT albendazole), but damage done to nervous tissue and kidney may not be reversable.  Just arrested.

Please also see:

http://www.bio.miami.edu/hare/paresis.html

and read the link on that page to the article by Dr. Susan Brown on that topic.  I hope it will give you some ideas.

Good luck,

Dana