I seem to have created a monster dog... Mia is now refusing to play with toys other than tennis balls. She loooooves fetch and would play it all day. When she's not playing fetch she is either carrying a tennis ball around in her mouth or rolling it around with her paws or de-fuzzying it. If I pick up one of her balls, she is at my feet just beaming in a crouching position and you can even see her quiver with excitement, and sometimes she will almost do a little excited scream (think tollers almost). If I'm sitting somewhere and I look down there will be 3-4 tennis balls at my feet when I get up. She would fetch all day every day if I let her. I'm wondering if she's too into tennis balls. I knew a pom that was so obsessed with a toy, she would carrying around 24/7 in her mouth. I'm really concerned since she will not play with toys other than balls now. If it's not a ball, it's no good.