Yes, they can eat tomato soup if it is not made with heavy cream, dairy or chicken stock. Plant based soups are vegan friendly. For my recipe, I used coconut milk and juices from the roasting. If stock is needed, I always go with coconut water first before using stock. Canned tomato soups are not vegan friendly because many use dried milk powder and/or other dairy products. Also, some will mention that they use chicken stock which is not vegan friendly