Published Wednesday, 11 July 2012
The dog - which belonged to Belfast woman Caroline Barnes - has been at the centre of a long-running international campaign to save it, since being seized by Belfast City Council two years ago.
But on Wednesday, the council confirmed that the destruction order had been carried out after a 28-day reprieve period ran out at midnight.
"Destroying a dog that had no history of aggression is folly and shames society," DUP leader Peter Robinson tweeted, having previously told Lennox supporters that he was unhappy with the outcome of the legal battle.
But the council said that, while it regretted that the court action was necessary, the safety of the public remained its priority.
"Whilst there is an exemption scheme to which dogs of this type may be admitted as an alternative to destruction, there were no such measures that could be applied in this case that would address the concerns relating to public safety," a statement added.
"The Council's expert described the dog as one of the most unpredictable and dangerous dogs he had come across."
In a statement on Tuesday evening, Lennox's family said they had been denied the chance to say goodbye to the animal.
"We are sorry to say at the present time Belfast city council seem to be intent on killing our boy," it read.
"Despite previous assurances otherwise, we have been denied the opportunity to say goodbye. We have also been told that we cannot collect his body and bring Len home.
"We have been informed however that we will receive 'some' ashes in the mail."
Lennox's story has grabbed the attention of animal lovers across the world, with hundreds of thousands of signatures on an online petition and protests held in New York and Belfast.
Celebrity dog experts like Cesar Millan and Victoria Stilwell have also shown their support for the 'Save Lennox' campaign.
Animal Rights Action Network director John Carmody described Northern Ireland's Dangerous Dogs Act as a "complete shambles".
He added: "People are today heartbroken, shedding tears and crying out loud with the news that Belfast City Council has murdered Lennox.
"Northern Ireland's Dangerous Dogs Act is a complete shambles and does nothing to protect their guardians, or the safety of the public from possible dog attacks. The legislation needs to be scrapped and completely reviewed with a view to Deed not Breed."
Mr Robinson has also said that he has written to the minister responsible, Sinn Féin's Michelle O'Neill, asking for a review of the law.
Belfast City councillor Pat McCarthy said he understands the family's position.
"I can understand because I'm a dog owner myself and over the years I have had to have dogs put to sleep, and they become part of the family," he told UTV.
"But we had to implement the law - we don't make the law, we are just charged with implementing it."
The council also said its members have received threats from campaigners and that contact with the PSNI in relation to those threats was ongoing.
© UTV News