Have you ever wondered how many heartbeats an average person has in their lifetime? What about for cats or dogs or other animals? Turns out because of metabolic rates and size of different species, each animal gets around a billion beats.
Around being the operative word, of course. Humans and chickens are outliers in that we get 2.21 billion and chicken gets 2.17 billion beats (I wonder how many actually see that much). But a lot of other animals sit on the 1 billion line: horses, pigs, rabbits, elephants, cats, whales, etc. Animals big or small, fat or strong, fast or slow -- it seems like there is a magic number for us all. Other than small dogs. They got the short end of the stick.