The Dog Anxiety Vest That Is Already Used by MILLIONS of Dogs ThunderShirt is the original, vet recommended, natural calming solution that may reduce anxiety in dogs in a drug-free way. Like swaddling an infant, our dog anxiety vest's patented design applies gentle, constant pressure to calm all types of anxiety, fear, and over-excitement issues in dogs. The ThunderShirt is recommended for thunder, fireworks, separation anxiety, travel, & vet visits. Treat anxiety, fear, and over-excitement in style! You’ll love the ThunderShirt’s calming effect on your dog.