No, but you can still give him a great day and he’ll be stoked about it. My kitties get tuna on certain holidays (like xmas). They don’t know why, but that doesn’t change how excited they are.

Sing the song

Your dog will enjoy his special day but then be disappointed it didn’t happen again the next day. Then he’ll get used to normal days until the following year.

I refuse to help until I see a photo of your dog blowing out their candles. Extra credit if they are wearing a party hat.

There’s no bad reason to give your puppy love and attention.

I think there could be some debate about how intelligent dogs are, but let’s brush right past that and assume they’re about as intelligent as humans.

Do you innately know it’s your birthday? Without a calendar, would you be able to tell it’s the annual anniversary of your birth? Let’s imagine further still that a bunch of other creatures (that you trust, but with whom you cannot effectively communicate) suddenly approach you in celebration and give you food, objects and attention. Would you be able to figure out why?

I think if you think it’s important that your dog understands it’s his birthday and you’re celebrating it with him, then, sure, he does. Buuuuut I dunno how realistic an assumption that is.

We always include the dog for Christmas. In my lifelong total of four dogs, they all were uncertain the first year, a little better the next year, and after three were all set to jump in and unwrap their presents. While they have no concept of Christmas and probably no explicit memories of previous Christmases, they do seem to learn year over year

You could start the day by looking at him and saying “birthday” and in 20-40 years he should catch on.

Oh, I’m sure he knows! Later when you’re both in Heaven (he, in Dog Heaven of course), you’ll both hang out at the Heaven Dog Park and you’ll both talk/bark about the good old days.