Petsmart sells Air Kong Squeakers, X-SMALL size, here's a link :
Air Dog KONG Extra Small Squeaker Balls - Toys - Dog - PetSmart
Our babies LOVE these, they're the PERFECT size for their little mouths (our dogs are 5-6 lbs.), and they squeak. They are just like little tiny tennis balls.
Maybe you can order some..........good luck.