When I was little, my mother worked at arestaurant, so our rabbits were fed vegetable scraps and entire head oflettuce as well as the piles of green grass I picked for them in themorning. Our rabbits were used to these feeds, as they wereraised on them.
A sudden change in diet can be fatal!
Gorging on a particular food can result in a terrible tummy ache oreven fatal chemical reation in a rabbit who's gut flora is notacclimated to digesting that particular food. Some animalsare more suseptible than others. Studies have resulted intheories statingthat gorging on certain foods creates achemical response that slows the gut down, resulting in proliferationof harmful bacterias in the gut including C. botulinum. (In otherwords, in some cases, botulism is the suspected cause ofdeath). This chemical reaction has been studied extensivelyin search for the cause of "grass sickness" in horses.
I would not take a chance -- throw the lettuce away and don't risk yourrabbit's health. Small amounts of vitamin packed fresh darkleafy greens are a far better choice. Good rule of thumbabout what to do with that old food in the fridge"If youwouldn't eat it -- don't feed it too your pet".
I may have already shared this story . . .
Years ago, a lady bought a bunny from us for herson. I advised that greens not be fed, as the bunnywas on a pellet diet. The little boy gave the bunny greensfrom a carrot top and the poor creature died and had been foaming greenfrom the mouth
Pam N.