See Spot Run (2001)

Plot

A skilled drug-sniffing dog becomes the target of a ruthless mob boss, prompting the FBI to relocate him for his safety. When a single mother is left without a babysitter, she reluctantly leaves her young son, James, in the care of her unreliable neighbor, Gordon, who happens to be a mailman. Chaos ensues when the dog, now known as Spot, escapes an assassination attempt and inadvertently hides in Gordon's mail truck, alongside James. Together, they embark on an unexpected adventure filled with humor and heart, as they try to evade the goons sent to finish the job.