Plato Pet Treats Salmon Thinkers are FREE from added sugars, artificial preservatives, by-products, artificial colors, protein-meals, soy, wheat, corn, fillers, and freeze-drying. Slow roasted in our own US Facility, these treats can be snapped into pieces for training dogs of all sizes or to share. Plato Thinker Sticks are grain-reduced with gluten free brown rice being the only grain ingredient. Brain-nourishing natural DHA and EPA helps support brain function in your dog.