| The juice of citrus fruits contains citric acid. Lemon juice contains approximately 7% of citric acid. Lemons and limes may taste sour but the fruit and juice of all Citrus fruits are safe to feed to birds in moderation. Irritation to the mouth is unlikely with the concentration of citric acid present in the juice. The fruit peels, thorns and other parts of Citrus plants contain limonin, an irritant substance, which can cause an allergic contact dermatitis in humans. Because of the possiblity of an allergic dermatitis, branches of the Citrus species are probably best avoided for perches. | |