Baby rabbit very lethargic and wont eat

Question
My 12-13 weeks old (not absolutely sure of his age, but this is close)dwarf rabbit won't eat today. This is very odd for him, as he eats constantly when given food--especially carrots. I gave him a carrot this morning and he hasn't touched it. His pellets, either. He is just laying around and I just found him laying on the floor in his pee. He NEVER pees on the floor, only in his cage. He is very well trained.
Please let me know if I should be alarmed or take him to see a vet. This strange behavior just started this morning.
Thank you very much!
Lisa
PS-he has taken to eating/shredding the newspaper in his cage lately. But it doesn't look like he did last night.

Answer
Dear Lisa,

Yes, get him to the vet ASAP.  This behavior could signal a serious illness.  Please see:

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

and go to:

www.rabbit.org/vets

to find a good rabbit vet who can help you.  It's important to find a vet who knows rabbits, and not just dogs and cats!

I hope this helps.

Dana