A wonderful addition to a DIY meal for dogs or cats, chicken liver is a good source of protein, fat, vitamin A and other nutrients. Its high fat content makes it especially good for young, growing dogs and underweight dogs. Vitamin A also is awesome for eye health. Make sure you don't overdo the percentage of liver in your DIY meals though, as it is a very rich meat and eating too much of it is particularly risky for cats (who tend to love it!).