A majority of pets exhibit stress. ThunderShirt helps reduce signs of stress such as separation anxiety, travel anxiety, and loud noises such as fireworks, thunder, etc. The ThunderShirt works by applying gentle, constant pressure (life receiving a wonderful hug) to calm all types of anxiety, fear, and over-excitement issues. Thundershirt is offered in sizes from XXS (under 8 pounds) up to XXL (over 110 pounds). You'll love the ThunderShirt's calming effect on your dog.