Santa's Little Helper one days collapses in the kitchen and he is rushed to the vet. It turns out that he has a twisted stomach and needs surgery. However, it costs $750.
The family decide to make cutbacks to pay for the operation: Bart must get his hair cut for free at the Barber College, and Marge gives up buying her weekly lottery ticket, and stretches the food budget by using low grade meats.
However, things turn bad for the family: Bart gets shaved bald and Marge's numbers come up on the lottery. The family blame Santa's Little Helper and the dog runs away. He is picked up at the dog shelter by Mr. Burns who is looking for an attack dog.
Bart goes looking for SLH, and eventually ends up at Burns' house. Burns tells Smithers to release the hounds on him, and Santa's Little Helper is about to tackle Bart, but remembers who his owner is just in time. The pair are reunited again.