Yes it is a scam as it happened to me a couple years ago when i was looking for a male fila. I got an email from someone that said that they couldnt take their fila puppy they just got into a certain place they were going and all i had to do is pay for shipping. Well im the biggest sceptic so i kept asking him questions and he kept dodging them and he wouldnt send me any pics, hmmmm. So i did a search like ruth did and yes found out that it is a big scam!
What happens is if you send the money for the flight and the crate, they so called will ship the puppy but then it will get re-routed to another airport were you need to cough up another amount of money to give to a broker of some kind and they just keep doing this but its all for not because there is no puppy being shipped at all, its just them telling you this crap. Once i kept on this guy to send me recent pictures and his contact info, i never got any pics or info, i then told him in my last email that i felt this was a scam and never heard back from them lol. So yes if it seems to good to be true, it probably is.