Michael Beaumont was convicted of killing his son, Kadan, by a jury at Sheffield Crown Court today.
A six-week long trial heard that Beaumont, 28, of Chapel Street, Hoyland, near Barnsley, claimed that Kadan was injured when he was knocked over by the family dog, Mia.
But prosecutors said this was a story he made up to disguise the horrific injuries he had inflicted.
The jury was told how emergency services were called to the family home on September 28, 2011, following reports that the baby had been unwell after being knocked over by the dog the day before.
Kadan was taken to Barnsley District General Hospital and later transferred to Sheffield Children’s Hospital where he died.
Pathologists later found 34 different injuries on Kadan’s body and said he died as a result of a heavy impact to his head.
Kadan’s mother, teaching assistant Helen Barnes, 28, was found guilty of neglect, the officers said.
Beaumont and Barnes will be sentenced tomorrow at Sheffield Crown Court by Mr Justice Globe.
Detective Chief Inspector Sean Middleton, who led the investigation, said: “This is a shocking case of violence from a parent, which sadly resulted in the death of an innocent young child.
“By blaming the family dog, Beaumont attempted to cover his horrific actions, but the evidence surrounding the cause of Kadan’s death, provided by expert pathologists, was overwhelming.
“Beaumont claimed that Kadan had been knocked over by the dog the day before, however, experts concluded that Kadan had died from head injuries that were likely to have been sustained only an hour before emergency services were called.
“This has been a particularly distressing case for all concerned and hopefully the end of this trial will bring some closure to the rest of Kadan’s family.
“I would like to thank the community of Hoyland for their help and support during this investigation.”