This is the moment a hero passerby paddled in surging water and rescued a drowning dog from a weir.

Thanakorn Thanasri was walking home with a relative when they spotted the stray pooch struggling to wade back into the banks in Nakhon Sawan, Thailand, on September 9.

Footage shows the good Samaritan wading against the current to reach the exhausted canine and swimming back to safety with it.

He let the mutt climb up first and it crawled up the slope where Thanakorn's nephew Garfield, 14, had been waiting. The pair took the wet pooch home and adopted it as a pet.

Thailand, a largely Buddhist nation, believes that kindness towards animals should be encouraged, with temples sometimes being a safe refuge for stray cats, dogs, and even monkeys that don't have homes.