Happy birthday, Bo Obama!

The lovable White House Portugese water dog turns four years old on Tuesday -- time flies! -- and he's grown a lot since the Obamas first brought him home back in April 2009. (He's still a puppy at heart.)

In his short spell at 1600 Pennsylvania Avenue, Bo's already chilled with Oprah, worn costumes, gotten his own Beanie Baby, pulled some pranks and made friends with Betty White -- and he even gets to sleep in the bed every now and then.

So, four years in, what's Bo's approval rating? Well, the presidential pup has gotten some very high praise. "He is the smartest dog on the planet," the first lady told David Letterman back in March. "He is my son. I have two girls and a boy ... He's very well-mannered, he's very even-tempered. He has a busy schedule, I mean appearances... we're thinking about getting him an agent."

Below, our birthday tribute to the great Bo Obama: his cutest moments caught on tape. (JUST WAIT until you see Bo's high-five skills.)

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  • Bo High-Fives Michelle Obama & Oprah

  • Bo Shakes Hands With POTUS, Hangs With Brian Williams

  • Bo Bark-Bombs A Press Conference

  • Bo Boards Air Force One Like a Pro

  • Bo & POTUS Go Shopping at PetSmart

  • Bo Works The Crowd Like A Champ

  • Bo Dresses Up Like a Bunny

  • Bo Video-Bombs a TV Broadcast

  • Bo Chooses Playing Over Talking to Reporters

  • Bo Pals Around With Betty White

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