Usually do not provide them in extra amount as it could have a far more adverse effect on their health and fitness than the benefits it carries. If your guinea pigs don’t like tomatoes, it is possible to serve them with other solutions like Cucumber, Broccoli, Zucchini, and so on. https://can-i-feed-guinea-pigs-to42964.bloggactif.com/22483760/can-guinea-pigs-eat-all-types-of-tomatoes-for-dummies