Prothrive is the ideal supplement for maintaining your dog’s joints, digestive system, and immune system. This supplement is specially formulated for adult dogs- but for senior dogs that need additional nutrition, try a sample of Prothrive Senior . If you liked this sample- you can find the full size product for sale here . To order penny sample size, simply add 1 quantity of the item into the shopping cart. *Limit 1 product sample per customer. * Samples are PENNY WITH ANY PURCHASE.