Many of the artificial coloring agents used in dog foods have been associated with potential problems. FD&C Red No. 40 is a possible carcinogen but is still widely used to keep meat looking fresh. Blue No. 2 is thought to increase dogs' sensitivity to viruses. Another color that is commonly used but that has not been fully tested is Yellow No. 5.
Both Red No. 2 and Violet No. 1 were banned by the FDA in the mid-seventies as possible carcinogens but prior to that were widely used in pet foods.
It's important to remember that artificial food colors or dyes used in pet foods are not for the benefit of dogs or cats — they're simply added to satisfy the pet owner's ideals of how a pet food "should" look.
Flint River Ranch premium pet foods and treats for cats and dogs contain absolutely no artificial colors or dyes.