A dog belonging to the leader of a dog fighting gang was forced to fight for 45 minutes, suffering horrendous injuries in the process, a court heard.
John Knibbs, 55, was convicted in his absence at Lincoln Magistrates' Court on Tuesday of keeping and training dogs for fighting.
He was also convicted of causing unnecessary suffering to two dogs.
The RSPCA said one of his dogs, Baddy, "suffered severe puncture wounds fighting a much larger dog".
"Although we never found Baddy's body, the pictures and subsequent text messages about the fight revealed there were severe puncture wounds to his head," Insp Kirsty Withnall said.
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The court heard videos found on Knibbs' phone showed dogs being forced to fight, and another running on a treadmill - a common technique used to build up strength for fighting dogs.
Another video showed two dogs ripping each other apart, with text messages talking about "the crushing of bones".
Insp Withnall told the court Knibbs was also trying to breed "the ultimate fighting dog" from the largest and most aggressive animals he could find.
Knibbs, of Polyanthus Drive, Sleaford, Lincolnshire, was first prosecuted for dog fighting by the RSPCA in 2009 when he was disqualified from keeping animals for life.
He was convicted of breaching his ban in 2016.
On investigation of a second breach, premises in Sleaford were raided in September 2017.
Eight dogs were found, including an American Bulldog, a Presa Canario, and a pitbull.
Further raids followed in Bloxholm, Lincolnshire, and one in Anglesey, Wales, where another of Knibbs' dogs, Panther, was found with fighting scars.
Kimberleigh Steele, 29, also of Polyanthus Drive, Sleaford, was convicted in her absence of aiding and abetting Knibbs.
Adam Scott of LLaneilian, Anglesey, who appeared at court for trial, was convicted of keeping two banned dogs.
He was ordered to carry out 100 hours of unpaid community work and pay costs of £3,000.