It isn’t just humans that celebrate their birthdays. Pets do it too.The most adorable picture ever. The dog just can’t contain his happiness. Anymore space cake? Cute walrus becomes shy when gifted a fish cake.When your dog realizes the real potential of her birthday gift.Jia Jia turns 37-years-old, thats 111 in human years. Owners celebrate Margaux’s adoption day. (Meet the cat in black: Cat Nimbus, celebrating his birthday just like a gentleman.  No doubt every dog should be so happy on its birthday.