The attack took place in Morse Close on October 8 last year when 53-year-old Desmond Francis was taking the dog out for a walk without a muzzle on.
Without provocation the dog bit a man as he walked past, prosecutor Shelina Khudurun said.
A woman then came to try to calm the dog down, at which point the dog sunk its teeth into her leg too.
Francis, of Sellincourt Road in Wandsworth, was charged with two counts of being in charge of a dog which caused injury and one count of allowing a fighting dog in public without a muzzle.
He pleaded guilty to the three charges in November and appeared at Willesden Magistrates’ Court on Thursday (March 6).
Prosecutor Ms Khudurun detailed the injuries caused to the man and women during the attack.
She said a “large chunk of flesh” was removed from the woman’s leg, whilst the man had puncture wounds from the bite.
The woman, who described herself as a huge animal lover, said: “I’ve been left with a horrifying injury whilst only trying to help.”
She explained that she now questions her safety in the area.
She said: “I truly feel this would have been prevented had the owner followed the right guidelines.”
The man who was attacked said: “I now have to use a crutch to walk around. I live up two sets of stairs and struggle to get up there due to my injuries.
“Psychologically I’m a mess. I’m extremely worried I’ll see the owner again in the area.
“On that road where it happened there are two schools and I dread to think what would have happened if the victim were a child.”
Francis, representing himself in court, said: “When I took the puppy out for a walk without the muzzle, that was my mistake.”
However, he accused the woman who was bitten of “aggravating” the dog.
District Judge Mark Jabbitt adjourned sentencing until April, warning Francis that this was a serious offence which could result in a prison sentence.
