THE TOP DOG: Nikita joins his partner, Lt. Thomas Chabot, at the Worcester County Sheriff’s Office on Friday afternoon. Adopted from the Sterling Animal Shelter, Nikita has been working as a drug-sniffing K9. He’ll be appearing in an upcoming episode of the PBS show “Shelter Me.”

FOUR LEGS ON DUTY: Nikita, a dog adopted from the Sterling Animal Shelter, walks with his partner, Lt. Tom Chabot, of Ashburnham, at the Worcester County Sheriff’s Office on Friday. Nikita will be appearing in an upcoming episode of the PBS show “Shelter Me.”
And he seemed to know it, too. When the dog saw himself on-screen, he started barking, as if on-cue.