Bunny losing weight

Question
A few months ago, I decided to let my bunny run loose in the house all day instead of just a few hours in the evening.  I noticed that she was eating Iams dog food out of the dog's bowl, but did not think much about it.  Then, I noticed that she was getting exremely thin.  Since I noticed her losing weight, I have kept the dog food away from her, keeping her in he pen most of the time and putting the dog food up when she is out.  However, she is extremely thin, and I want to give her something to help her gain weight again.  She acts fine, and is active, and eating her pellets, hay, and fresh veggies.  She has no diarhea, but is literally "skin and bones".  I bought her some Critter Be Better at BusyBunny.com, and she loves it.  I feed her some every evening with her evening meal  She will be 5 on Feb. 11, 2011, and she was born here, so I know here exact age.  She has been on the same diet of pellets, hay, veggies, all her life and has been fine until she started eating the dog's dry food.  How can I help her to gain back the needed weight?

Answer
Dear Marlene,

First, you need to be sure that she is actually swallowing the food she is eating.  Sometimes a rabbit with severe molar spurs will eat eagerly, but not be able to get the food down in sufficient quantity.  It's certainly not normal for her to be skin and bones if she's eating well.

Another possibility is renal disease, which can cause wasting and weight loss in its later stages.  If your bunny is drinking excessively and urinating copious, dilute urine, then it would be wise to have a good rabbit vet draw blood for a complete blood chemistry and blood count so her renal function (and other major organs) can be tested.  The blood count will tell the vet if there is a cryptic infection that could be contributing to the problem.  

A diet very high in protein can tax the kidneys, but I think unless she was eating the dog food over a very long period, this would not be enough to do that much damage.  Still, this is something to consider.  If she had borderline renal function before eating the dog food, then the high protein food might have pushed her farther over.

You can find a good rabbit vet here:

www.rabbit.org/vets

who can examine and diagnose your bunny in person, which is really what's needed at this point.

Hope this helps.

Dana