Jinx, our 7 year old cat would not chase his new 4 month old friend Casey (AKA Pinball) who for 1 year bounced around the house, off of walls, up the stairs and down again. Casey ran into jinx, over Jinx, under Jinx and could not get him to play. When I saw Jinx run around on his own, and chasing his brother for a couple of days I told my husband, who said two weeks earlier he’d started Jinx on SierraSil pet chews without my knowledge! I would never have believed the difference it made if I had not seen it with my own eyes. Jinx was having fun again!