As with most medications and supplements, the dosage of Valerian root depends on the size of the dog. The general rule of thumb offered by Schnauzerama is to give a dog 4 milligrams of Valerian root per pound if using the pill or capsule form.
Valerian root is used to relax dogs that are stressed due to separation anxiety, vet visits, thunderstorms or other loud, unexpected noises, according to Pet Nutrition Info. Valerian also is available in liquid form. The recommended dosage for liquid Valerian is about one-fourth the human dose for smaller dogs, one-half for medium-sized dogs, and a full human dose for large dogs. There is no known maximum dosage of the supplement, but animal owners may wish to discuss Valerian with their veterinarian before giving it to their dogs, advises Pet Nutrition Info.