Lethargic Mini Lop - Starvation?

Question
Hello, and thank you for hearing my question.  I have taken 1 of our 2 bunnies to the vet, she is still there, being given fluids, etc., trying their best to save her, I believe she was near death.

I just wanted to talk to someone about this.  This morning my daughter and I saw our 2 bunnies we keep in our house and they seemed fine, within about 2 hours I went by the cage and saw that my daughters bunny, a mini lop about 4 mo. old, was lying flat in the cage.  I immediately lifted her out and she look near death to me.  We rushed her to the vet, she was so still, and felt cold.  When the vet examined her we discovered she was still alive, but he said she was sooooo thin, no meat on her bones.  We have had our 2 bunnies for about 2 months, and they eat like horses!  I give them unlimited Timothy Hay and vegetables every other day, no pellets at this time because it gave them diarrhea.  I read that timothy hay was the best thing for them, but now after more investigation I see a little bit of quality pellets should be fed too.  But the way she eats constantly, I can't believe she could be starving.  I haven't had rabbits for a long time and I didn't feel her thinness through her very thick coat, I feel guilty about that now, that I didn't examine her more fully.  Our other bunny is a Lion Head, who is on the same diet.  I examined him and he has muscle around his back bone and I can feel a rounded tummy, so his weight seems o.k., but I will be taking him into the vet after we see what happens with our Mini Lop.
Have you every seen a bunny with similar symptoms as our Mini Lop?  Do you know what might cause her not to put on weight, although she is eating very well?  Thank you for any input.  Please don't scold me at this time, I am truly sorry for anything I have done to cause harm to our bunny, we love her.

Answer
Dear Julie,

Did you actually watch the little one eat? Sometimes a bunny will *try* to eat, and appear to be eating ravenously, but the food falls out if she has severe molar or incisor malocclusion/tooth overgrowth that is preventing her from actually chewing and ingesting the food.  This is more common in lop and dwarf rabbits with short faces.  Note that lionheads are also prone to dental problems, so both rabbits should have regular dental exams done by an experienced rabbit vet:

www.rabbit.org/vets

I hope the vet is able to save your bunny. This is such a terrible, sad thing.  One reason we recommend that rabbits live inside the house with the family is that it's easier to catch on to things like this and address them before they become critical.

I am sending many healing thoughts to your bunny.

Dana