So I'm the owner of a high end doggy daycare and we buy gifts for dog parents when the dog's birthday rolls around. I've seen it all, and in terms of what gift get's the best reaction from our clients, I can definitely recommend getting a Custom Movie Poster made for your dog, and if movies aren't your thing, you could get a custom magazine cover. Outside of custom and unique gifts, you could go for one of those cheap unbreakable chew toys. Which is more of a gift for the dog, though less enjoyable for the family to enjoy also.