This organ donation video about a man and his dog will make you cry

This touching video about a man and his dog has gone viral and has been watched more than three million times since its release.

The Argentinean PSA is designed to raise awareness around organ donation - and is also designed to make you cry like a baby.

The ad follows the story of an elderly man and his loyal companion. One day, the man has to go to hospital so the dog waits outside for him to come back.

The person that comes back is unexpected but familiar.

There aren't enough tissues in the world.

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