Hi. I need help with my stubborn Russian Tortoise (Boris). He will only eat romaine lettuce and occasionally carrots. I've tried commercial tortoise pellets and other leafy greens with no success. I've been reading other posts and sounds like this stubbornness is common. I've never tried mixing up the romaine with the other greens. I'm just not sure how long I should let him go on a hunger strike if he starts one? I don't want him to get sick from not eating. He went to the vet recently and received a good bill of health! Also, is there a reliable source that anyone recommends I use for proper diet and care. Thank you for the help!