Police have stepped up patrols on Tooting Common following a savage dog attack which left a dachshund fatally injured when it stepped in to protect its pup.

Joanne Jones' dog Lily, 3, and her pup Leo, nine months, were being walked on Tooting Common on Sunday, July 3, by her housemate Nicole Mony, when they were set upon by a pit bull type dog.

The dog bit Leo before his mother jumped in to protect him.

But Lily sustained multiple injuries protecting her pup that she died the next day.

Ms Jones, 36, from Laitwood Road, Balham, is so traumatised by what happened to her beloved pet that she has decided to leave London.

She said: "She was just walking them past the Lido and she heard it coming towards them.

"It went for Leo and then Lily tried to defend him. But it let go of Leo and just turned on Lily.

"The owner came over and held the dog down on the floor. But it escaped and went for her again. He then just picked it up and said to the dog 'What did you do that for?' and walked off towards Aldrington Road without saying anything."

Lily was taken to the Queen Mothers Hospital for Animals in Potters Bar and had an operation to stabilise her injuries which included a ruptured pancreas and intestine and a punctured lung.

But before having a second operation, she went into cardiac arrest and died.

Ms Jones reported the incident to the Metropolitan Police and Wandsworth's dog warden, and attempts to find the owner of the attack dog are continuing.

Sergeant Eric Ostrowski of Bedford SNT said: "We are aware of the incident and are currently working with Wandsworth Council's Parks Police in order to trace the owner of the dog responsible for the attack.

"We have stepped up patrols on Tooting Common in order to reassure dog walkers in the area."

Ms Jones also told fellow residents of the attack on local website Streetlife asking to help find the dog's owner.

She said: "I am devastated in losing her, she was only three and literally came everywhere with me.

"Leo is as sad as anything. He has still got two bite marks and stitches around his chest.

"I'm not having her dying in vain. These issues seriously need to be looked at."

She added: "I just want this guy caught."

Anyone with information about dog attacks on Tooting Common or in the borough to contact Bedford Safer Neighbourhoods Team on 020 8721 2424 or Wandsworth Parks Police on 020 8871 7532.