Sorry to hear that, and while I love your giving them a fresh diet, I do have to point out that many rat lovers also realize that it's difficult to know you are giving them a nutritionally complete diet when feeding them like this.

Rats are considered omnivores, but I didn't hear anything but veggies and fruits in your short list. Veggies and fruits are good, but I ask you if you give them any sort of lab block or Becky's diet 24/7, and are only supplementing with fresh fruits and veggies?

There is also the Rat Lady's diet...
http://www.ratfanclub.org/diet.html

I strongly feel that you should look into getting a high quality lab block, or mix like Becky's. I really think your on the right track, but need to offer them the choice of eating a nutritionally complete diet with lab blocks involved. Not just the fruits and veggies alone.