True story.
My neighbor got a greyhound puppy this year. Though very hard to get, he has rescued greys before and had a good relationship with the rescue group. I saw his pup at just 8 weeks and asked whether it was a girl or boy and he said they didn't now yet and would have to wait to find out definitively when neutered. But they think it's a girl.
How can this be? Well, the pup was born to a female at a racetrack. Apparently, the females are given testosterone shots to keep them from getting pregnant, but this mom was already pregnant when given the shot. I didn't see the puppy's anatomy but I'm guess the hormones gave an intersexed appearance.
Strange, but interesting. And a darn cute pup, it is.