A guy walks past a pet store. There is a sign in the window that says TALKING DOG FOR SALE.

The guy doesn't believe it, but is curious, so he goes into the store and walks up the the talking dog and says "Hello". The dog says "Hey. How you doin'?"

The guy says "Wow! You can really talk!" The dog says "Yep. That's right" The guy says "What is it like being a talking dog?"

The dog says "Well, I've lived a very full life. I rescued Avalanche victims in The Alps. I worked as a drug sniffing dog for the FBI, and now I read to people in an old folks home five days a week."

The guy is just blown away. He turns to the owner of the pet shop and says "Why in the world would you sell a dog like this???"

The pet show owner says "Because he's a damn liar! He never did ANY of those things."