The 47-year-old victim, who was known to the defendants, only managed to get urgent medical help after he escaped from being locked in the bathroom of a house in Hartington Road, Rotherham.
He collapsed in the street on the morning of Friday, February 22, and emergency services were called who took him to safety.
Gemma Muscroft and Nathan Liversidge have now been jailed over the attack for a combined total of 36 years.
In a statement issued after the case was heard at Sheffield Crown Court, Detective Sergeant Matt Jackson said: “The victim was lured to the home of Gemma Muscroft, in Hartington Road on the morning of Thursday, February 21, to take Muscroft some food after she called him.
“When he arrived at the house, Muscroft and her friend Nathan Liversidge, who was also at the house, subjected him to an extremely violent, sustained and unprovoked attack.
“The pair proceeded to assault and injure him with numerous weapons including a belt, scissors and a large serrated piece of metal, leaving him with life-threatening injuries to his neck, hands and body.
“They then locked him in the bathroom, knowing full well how severely injured he was, fleeing the scene and taking the victims 11-week old Staffordshire puppy.”
The following morning, the victim managed to escape the house and was found by members of the public, gravely injured.
He was given immediate medical attention and numerous police officers from Rotherham were deployed to apprehend Muscroft and Liversidge.
The pair were arrested and charged two days later.
They appeared at Sheffield Crown Court for sentence on Friday.
Muscroft, aged 32, of Hartington Road, Rotherham, pleaded guilty to section 18 assault, false imprisonment and theft of the dog.
She was sentenced to 18 years in prison.
Liversidge, aged 30, of no fixed address, pleaded guilty to section 18 assault and false imprisonment. He was also jailed for 18 years.
DS Jackson said: “Both Muscroft and Liversidge have failed to provide any explanation as to why they did what they did.
“The level of violence he was subjected to is appalling and some of the worst I have seen in my many years of policing. I echo the words of Judge Richardson who described the attack as abhorrent, savage and sadistic.
“They have left him with lasting injuries and no doubt the mental impact will stay with him forever.”