LIVE ducks were thrown to dogs to give them a taste for blood before they fought to the death, it has been revealed.

Senior police and RSPCA officers last night pledged a major crackdown on the criminals behind the illegal sport.

It follows early morning raids on Teesside yesterday, which saw seven suspected members of a dog fighting ring arrested.

The culmination of a ten-month surveillance operation, it also saw four heavily-built pit bull terrier-type dogs led into restraint cages by specialist RSPCA officers.

Operation Bale is believed to have broken up a gang suspected of using dangerous dogs for social status and organising spectator battles in alley-gated arenas near homes.

An undercover police officer, working on the case, revealed that those involved were believed to have thrown stolen livestock, including ducks, to the dogs to give them a taste for blood before the fights.

Yesterday's raids followed the discovery of a mobile phone video showing an organised dog fight in the South Bank area of Middlesbrough.

It was held behind terraced houses in an arena surrounded by steel gates.

PC Ian Soloman, wildlife officer with Cleveland Police, said: "The footage shows two dogs being baited and encouraged to fight each other. One dog is a skilled fighter and goes for the other dog's throat and tries to rip it to pieces. It is abhorrent and very disturbing."

Acting Inspector Mike Cane, who took part in yesterday's raids, said the mobile phone footage was crucial to the investigation.

He said: "The investigation has intensified in the past two weeks and we are extremely pleased with the end result, which was the culmination of intelligence-led surveillance."

RSPCA Chief Inspector Justin Lemasurier said: "Intelligence suggests this is not an exceptional case and, unfortunately, we believe this type of thing does take place throughout the country.

"I find it extremely difficult to understand, as do all the investigating officers, but when you meet the people involved in this type of activity and realise what sort of people they are, it does, unfortunately, not surprise me."

Five dogs were seized by specialist RSPCA officers yesterday.

As well as the four pit-bull type dogs there was a timid terrier breed, which is believed to have been used to bait the fighters.

Using electric shields, Cleveland Police raided five addresses in the South Bank, Grangetown, Brambles Farm and Eston areas of Middlesbrough.

PC Soloman said: "One particular dog was quite vicious when officers tried to apprehend it and a special noose had to be used to detain it."

The breeds of the seized dogs will be investigated by the RSPCA and if they are found to be illegal pit bulls, they are likely to be put down.

As well as targeting the dangerous animals, officers uncovered an extensive cannabis farm with £10,000-worth of plants.

Three of the suspects were also arrested for drugs offences and a further arrest was made for the illegal extraction of electricity at a property in South Bank.

Acting Insp Cane, who said there could be similar raids in the future, said: "There is a clear link between criminality and this is the start of a major crackdown.

"The dangerous dog avenue would appear to be something on the increase in this area."