The six-year-old dog lives at the Canine Defence League in Liverpool.

He's so happy there he couldn't stop his tail wagging furiously every time a visitor walked by.

Unfortunately, he kept hitting it against the side of the kennel and it broke.

The staff tried to fix it by wrapping it in bandages.

The wagometer

But Jake was in too much pain and the vet had to cut off the broken part.

Luckily, he's fine now and looking for a new home.

Strangely, a wagometer's just been invented which could have told if Jake was really in a good mood or not.

The Queen's dog expert Dr Roger Mugford has made the sensor which straps to a mutt's tail.