Boost Nat Treat Beef Liver for Dogs 150g. Boost Their Treat. Treats are a big part of your dog's life for training, rewarding, occupying or just showing love. 100% natural, air-dried body part range free from nasties, so you can treat them for all occasions, guilt-free anytime. Supports Immune Function. Liver has high levels of vitamins and minerals, particularly vitamin A and zinc, contributing to a healthy immune system. High Protein Liver is a great source of protein, which helps with muscle recovery. Low Fat Suitable for dogs with dietary restrictions.