Vetoquinol Zylkene Capsules Calming Supplement for Dogs, 30-count; Help keep your furry friend calm during stressful times with the Vetoquinol Zylkene Behavior Support Capsules Medium Dog Supplement 225 mg. The non-drowsy formula uses alpha-casozepine, a natural ingredient found in cow’s milk, to help balance the stress reactions of dogs safely and with no tranquilizing or sedating effects. Milk-sourced alpha-casozepine is known to promote relaxation in babies, and it works in a similar way for your pal, giving him a sense of comfort and contentment to help him cope with stress or adapt to new situations. It’s perfect for most doggie stressors like loud noises, visits to the vet or groomer, as well as unfamiliar people and places. Plus, it’s free of lactose and preservatives, making it ideal for sensitive doggies’ tummies.