Is tuna good for a dog?

Tuna fish is OK for dogs - it is a good source of protein and unsaturated fatty acids that help support muscle development. However, tuna are predatory fish at the top of the food chain, so there is a risk of Mercury poisoning if you feed too much tuna fish to your dog. There is also a slight risk that your dog may have a food allergy to tuna fish - if your dog develops unexplainable skin rashes, you should ask your veterinarian about this.