Happy Birthday, Arthur! This little dog looks so adorable in his blue harness (or is it a dog bandana?), and he seems completely content on his mama's lap. Whether or not he knew that this party ...

Related: 30+ Dog Birthday Captions for Your Lovable Pup ... Consider a cute hat or fancy bandana if your pup gets stressed out with costumes. Every pawty needs tasty treats! Head to your local ...