To clarify further on Coccidia which I briefly mentioned… A lot of what happens is coincidental.
Rabbit breeders treat their “breeding stock” and the babies with a diluted medication to control Coccidia. The dose is usually too low so it CONTROLS it, but does not CURE it.
Next…
You bring home your baby bunny at 8 weeks and suddenly he/she is no longer getting this low dose medication from the breeder, so the Coccidia is allowed to flourish. Pet store bunnies have been without this medication even longer, that’s why they sometimes seem “sicker”…
Fast forward to 12 weeks old…
Sources say you can start feeding veggies at 12 weeks old. People start feeding iceberg lettuce (or any lettuce). Coincidentally, this is also when the bunny starts showing symptoms of Coccidia (diarrhea, listlessness, weight loss).
Not being aware of what Coccidia is (and not seeking prompt vet care), people assume the illness is due to lettuce and they stop feeding it. The bunny does not get better though (if vet care isn’t provided), and passes away.
Now this person thinks… LETTUCE = DEATH, which is simply not true.
So that is the long version of the misconception about lettuce and bunnies. Hopefully that helps!