iluvguineapigs4
Junior Guinea Pig
Who feeds romaine lettuce as their foundation food (food fed everyday)? And have your guinea pigs suffered from it? Liver related? Just curious 
Here is the guinea lynx food chart: http://www.guinealynx.info/chart.html, which is sortable for the vitamin A content if you click on the column second from the right.
Personally, I would not feed any lettuce daily because they and carrots are the foods highest in vitamin A.
Cucumbers and Romaine lettuce are two of the only veggies my boys will eat. They will also eat most fresh herbs so I try to get them those as much as possible.
Nope. They are just as active as ever. I fed my first Guinea Pig Romaine about every other day and he wasn't sick a day in his life and lived to be about 6.5
Don't give them too much of course, anything is bad if given too much of. They usually each get a leaf per day.
Having lost one of my older pigies to liver failure, I have become a bit more cautious where vitamin A is concerned. The ph : ca ratio doesn't take vitamin A into account.