Grain-Free Soft Liver Dog Training Treats - Real Liver Recipe - 56 g Great Jack's Soft Liver Dog Training Treats are 100% Canadian made and sourced all-natural dog treats. These amazing treats contain 60% human grade pork liver, so you can be sure your dog is eating only the very best there is to offer. Ideal for use as reward treats, featuring a low-calorie formula to allow you to feed without guilt! With an amazing flavor that canines love, Soft Liver Dog Training Treats are a great way to teach your dog some new tricks.