getting confused

when looking up what rabbits can and cannot eat I am getting mixed messages, some say they CAN have Lettuce and Cucumber and others say that that CANNOT have either, so where am I supposed to get a list that I can follow safely.

So far I know they both love
apple -small amounts-
celery
one likes carrots the other does not

I want to give them a healthy diet but get worried what to give them, we had a guinea pig but he passed away after having an opp to grind his back teeth done, I think he ate too much lettuce, carrot, cucumber and other things rather than hay, so now I limit anything other than hay and pellets to be safe, but we do like to give them a treat once every few days.

Please can I have some advice on what they can and cannot eat.

OOOOOOpppps just noticed I put this in the wrong section sorry

all mine bar 1 LOVE cucumber, I have alwys given it to them, spring greens is another favourite as if brocoli, and bell peppers!

Things like apple and carrot are high in sugar (all fruit is) and should be fed sparingly. Herbs are a great thing to feed, most are fine except chives, though check on a list first. Cucumber is fine, I'm unsure on lettuce, I've never fed it myself, with some there is too much of a certain thing in it so to be safe I just don't feed any.

http://www.rabbitwelfare.co.uk/resources/content/info-sheets/safefoods.htm

thank you for the info