This is Ira Glass of This American Life.

Each week on our show, we choose the theme, tell different stories on that theme.

All right, I'm just going to stop right there.

You're listening to an NPR podcast.

Chances are you know our show.

So instead, I'm going to tell you, we've just been on a run of really good shows lately.

Some big, epic emotional stories and some weird funny stuff, too. Download us,

this American life.

You're listening to Shortwave from NPR.

In the United States, we count how many humans live in our country. We also know how much

livestock like cows, chickens, and pigs are here.

And we even have estimates for wildlife populations like birds and bears.

But for pets, not so much.

We have no idea how many dogs live in the United States.

That's Audrey Rupple, a veterinarian and data analyst at Virginia Tech.

She says that not knowing how many dogs there are means we have a huge knowledge gap on health and disease trends and even how long dogs live.

She's trying to change that.

The goal of the dog aging project is to help us understand what really makes a healthy lifespan for our dogs.

And for Audrey, health and lifespan, there are really two different things that both need care and attention, even if it's easy to take that first word health for granted.

I think that for all of us, when we talk about wanting our dogs to live a long lifespan, what we really mean is we want our dogs to live a long healthy lifespan.

And I think that we don't often differentiate between those things.

But with the dog aging project, she and other researchers can start to.

...