A guy is driving about in the sticks of Moray and he sees a sign in front of a broken down, farm house:

 Talking Dog For Sale. 

He rings the bell and the owner appears and tells him the dog is in the back garden

The guy goes into the back garden and sees a bonny looking Labrador retriever sitting there.

“You talk?” he asks.

“Aye,” the Lab replies.

After the guy recovers from the shock of hearing a dog talk, he says “So, what’s your story?”

The Lab looks up and says, “Well, I discovered thit a could talk when I was a wee pup. I winted to help the country cain, so I told MI6. In nae time at a’ they hid me jetting fae country to country, sitting in rooms wi spies an world leaders, because nae one thought a dog wid be eavesdropping.

“I wis one o’ their maist valuable spies for eight years running. But the jetting aroond really tired me oot, and I knew I wisna getting any younger so I decided to settle doon. I signed up fir a job at the airport tae dae some undercover security cain, wandering aboot near suspicious fowk and listening in. I uncovered some incredible dealings and wis awarded heaps o’ medals.

“I got merried, had hunners a puppies, and noo am just retired.”

The guy is amazed. He goes back in and asks the owner what he wants for the dog.

“Ten quid will dae,” the guy says.

“Ten pounds? This dog is amazing! Why on earth are you selling him so cheap??”

“Because the dog’s a bloody liar. He nivir did any of that shit , am fed up listening to his nonsense.”