The attack on four-year-old Sally left her lucky to be alive, according to her vet.
Her left ear was torn off, veins in her neck were exposed and she suffered multiple wounds after being set upon in a park in Leeds on January 15.
Owner Christine Graham, 70, has spent £3000 on veterinary bills so far, which could rise to £5000.
Vet Simon Bate said: 'We have seen a number of these types of cases but this is probably the worst I've dealt with.'
Sally was being walked by Sheila Hodgson, a friend of Mrs Graham, in Roundhay Park when Mrs Hodgson began to chat to the woman walking the Staffies.
The trio then pounced on the smaller dog - and another dog walker had to intervene to stop the ordeal.
Mrs Hodgson said: 'Two of them had Sally by the ears and one was at her behind.
'We both tried to get them off her but couldn't. It was horrendous.'
Mrs Graham was on holiday at the time of the attack.
She said: 'I couldn't believe it when I found out what happened. She's a really friendly dog and wouldn't hurt a fly. It's a wonder they didn't kill her instantly.
'She was more dead than alive a week later.'
Mrs Graham called for the Dangerous Dogs Act, where an owner can be prosecuted for allowing their animal to be out of control in public, to be tightened as prosecutions are rare.
(Daily Mail - Feb 7, 2013)
