I know Zeke likes tennis balls but what about soccer or basket balls? These are a much much higher value reward to Zac than a tennis ball. I kick the ball around, protect it, pass it, tackle him, Zac growls like thunder while he dodges and catches and generally has a whale of a time.Come to think of it....maybe Treiball is the answer for Zeke!!! Mini-revelation. I know what I'll be researching after work!