I really don't see a problem with people throwing a party for their pets - its' entirely up to them

I guess for everyone saying that the pets' don't understand what the party is about, well ... i figure the thought process of a dog is about the same as a 2 year old - i wouldn't expect a 2 year old kid to understand that its their birthday either, only that they're getting to be the centre of attention, and treats and food. I know I don't remember my second birthday, but i'm sure my mom does.

So, a pet party, while making your pet happy with extra attention and treats, is likely more for the pet parents than the pet itself. Plus, you can get some really cute pictures of your pet in a party hat