Raymond Burrell, 38, battered his disabled neighbour Matthew Sheehan, over the dog barks - and he's still in a coma more than seven months later.
The 34-year-old was repeatedly punched and suffered horrendous injuries to his head and body in the attack in September last year.
Matthew is yet to regain consciousness and medics say he is still in a vegetative state.
Prosecutor Michael Jones said: "This was a deliberate, severe, and merciless attack."Burrell - who lived across the street to Mr Sheehan in Adamsdown, Cardiff - became "annoyed" at
his neighbour's repeated complaints about his dog making noise at night.
Mr Jones said a neighbour heard Mr Sheehan shout "shut up" on numerous occasions towards Burrell's flat - and even saw him go over the the flat to complain in person.
He said: "The same neighbour said he was woken by loud banging around 7am coming from Mr Sheehan's flat.
"From his window he heard shouting, screaming and a thudding noise as though someone was being kicked." Cardiff Crown Court heard Burrell appeared outside the flat and was arrested by police after a struggle.
Investigators found Mr Sheehan's DNA on Burrell's shoes after he allegedly kicked him.
Graphic pictures of Mr Sheehan's injuries including bruising to his brain, laceration of his left eye socket and many facial injuries.
Mr Jones said: "He has still failed to regain consciousness and remains attended by medical professionals."Burrell, of Adamsdown, Cardiff, was found guilty of inflicting grievous bodily harm but cleared of attempted murder.
A statement from Mr Sheehan's father Martin was read out in court describing the "heartbreak" of the family.
Martin Sheehan said: "The day Matthew was attacked will forever be etched in our memories.
"We know it was only the actions of neighbours, hospital staff and paramedics that saved Matthew's life.
"He remains in a serious condition in what we would call a vegatative state.
"He will be completely reliant on medical care for many years to come which means he can't do anything himself.
"The life he had has been taken away by Raymond Burrell.
"We spend every day at his bedside hoping he will recognise us or get better. But there's been very little progress since the attack. "We've kept his glasses next to his bed hoping he will wake up and wear them again.
"We couldn't believe what condition he was in at the hospital. We were in complete shock and couldn't take in what the doctors were saying to us.
"His life has been changed beyond recognition. We don't know what the future holds for him. "It's difficult to understand why a person would inflict such horrific injuries on another person. There's no way Matthew could have defended himself. You could blow Matthew over.
"All we can do is sit and hold his hand."
Sentencing Burrell at Swansea Crown Court, Judge Paul Thomas said: "You became irrationally irritated at the minor event of Mr Sheehan ignoring your warnings of complaining about your dogs barking.
"You went to his apartment early to assault him. You knew he was a vulnerable individual due to his medical condition. He used a crutch and also had a tremor.
"You left him in a pool of his own blood, but returned.
"Your intention was to make sure he was never able to say what happened to him by your hands and feet.
"You stamped on his head and then dragged him back into his flat and into his lounge, closing the doors behind him.
"You were indifferent whether he lived or died as long as he couldn't tell anyone what happened.
"Your volcanic temper shows that when you lose it you lose all semblance of human restraint.
"The injuries suffered by Mr Sheehan are tantamount to a mental death.
"He may continue to exist as a shell but will never be able to enjoy life with his family and friends."
Burrell, who served seven years for manslaughter after shooting girlfriend, Amie Miles, 17, in 1993, was sentenced to life imprisonment, and will have to serve at least eight years before he can even be considered for release.