WARNING: You'd better have some tissues handy when you watch this ad - it's a real tear-jerker!
This public service announcement for an Argentinian liver transplant foundation shows a day in the life of an elderly man and his loyal dog. One night, the man appears to have a medical emergency and is taken to the hospital. The dog follows him there and is left to wander outside of the building. After what seems like hours, a woman in a wheelchair leaves the hospital, and the dog races up to her. The implication is that its owner, an organ donor, saved her life (bet you didn't see that coming!).
Although the ad doesn't contain any speech, there are lots of ways teachers could use it in class. The obvious one is to show the ad, but stop it before the 'Become an organ donor' message at 1.20. Get the students to discuss what is happening. If you're a teacher, I'm sure you can think of lots of other ideas, but let me just recommend a book I bought recently by Kieran Donaghy, who runs the award-winning Film English site. The book's called Film in Action and contains loads of suggestions for using videos like this one.