The Jack Russell terrier got into difficulty at Whipsiderry, Newquay.
After failing to rescue the dog, the three managed to make their way back to shore to waiting paramedics and were treated at the scene.
Both of the town's lifeboats were launched - one of them picked up the dog, which was then taken to a local vet for an examination.
After the three people managed to get back to shore, the dog was still in the water and swimming frantically in circles.
As the Newquay D-class lifeboat Valerie Wilson rounded a corner, the dog spotted it and started to swim towards it.
The lifeboat came as close to the dog as was safe but was still a few metres away.
A crew member entered the water and swam to the dog. He then swam back to the lifeboat with the animal.
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©