After the Simpsons regret paying for an expensive surgery for Santa's Little Helper, he runs away from home and is trained by Mr. Burns to become an attack dog.
Lottery fever hits Springfield, but the Simpsons are forced to forgo a lottery ticket, and many other luxuries, to pay for a life-saving operation for their dog, Santa's Little Helper. All their personal lives are affected negatively by the sacrifice, and they come to resent Santa's Little Helper. He runs away and is captured by Mr. Burns, who trains him to be a guard dog.—Anonymous