It sounds as if Wishbone was a dog watching boys play basketball. He was comparing them to what dogs do. Speedy= fast kibble= dry dog food which is used to reward dogs to do tricks. Attaboy= a word used by pet owners to encourage their dogs after they have done the right thing, after they have been rewarded with a handful of kibble .

Kibble : To bruise; to grind coarsely; Attaboy: Used to show encouragement or approval to a boy or man. Attaboy! That's the way to hit a home run!