My male cavalier, Cooper, has tennis ball compusions as well!

We have to take his away from him, too, because otherwise it gets ugly. He loves to play with anything (as does Zoe), but those tennis balls...WOW! (He also pulls the fuzz off them at times.)
Did you ever see the movie Spanglish...when she says "DON'T throw the ball!!!"? We quote that hundreds of times.