soft tissue mass

Question
Okay, I have noticed over the last couple of weeks that my 6 month old, nuetered male mini-lop has been less energetic, and not eating very much.  I lost my 7 year old female mini lop to cancer earlier this year so I got a little paraniod and took him  to my vet yesterday.  My vet, while not a rabbit "expert," breeds rabbits himself, so I value his opinion highly.  He felt around on Sasuke (my bun) and found what he called a "soft tissue mass" on his right side beneath his stomach.  He did an xray and the mass is quite large (as big as his fist).  It has a very thick membrane and he said it appears to be full of gas.  You can see bits of food and more gas in his intestine.  You can also see his stomach, and kidneys.  My vet has no clue what it could be.  He has never seen anything like it.  He says I may have to take him to an expert in Berkeley, CA (about 3 and a half hours from where I live).  He has an ultra sound machine coming tommorow to see what the "mass" is conected to.  He says my bunny will have to have surgery.  My question is this: Do you have ANY idea what this could be?  My vet says it might be an absess, but he seems to have his doubts.  I wish I could post a pic of the xrays, but please, if you have any ideas I would (and my vet would) great appreciate it.  I already lost one fantastic rabbit and i can't bare the thought of losing him too.  again, any ideas you may have would be greatly appreciated.  Thank you very much for taking time to read this!

Answer
Dear Nina,

I would *definitely* take the bunny to one of the many rabbit experts in the Bay area before you allow anyone to think about surgery for something like this.  If the vet is not a rabbit expert, and doesn't see many rabbits, I'd wonder if he might not mistake a normal part of the rabbit anatomy (perhaps the cecum?) for something abnormal.

A cecum can become gassy, as can parts of the intestine.  I've never heard of a gas-filled *mass* in the abdomen.  And I'd *really* want a rabbit expert to have a look at the radiographs before I did anything more.  Your vet could even scan and email the radiograph to a rabbit expert vet to get an opinion.

You can find a very extensive list of rabbit-savvy vets in northern CA here:

www.rabbit.org/vets

Please also read:

www.bio.miaim.edu/hare/sickbun.html

and it would not hurt to give the bunny some simethicone to relieve gas pain/pressure.  You can get pediatric simiethicone suspension at any drug store, and give bun about 1cc by mouth (carefully and sideways, so he doesn't inhale it).

I hope this helps.  Please get him to that rabbit-savvy vet as soon as you are able.

Dana