A man who set fire to a dog after tying it to a tree and dousing it in petrol has been jailed for nine months.

Alastair Graham, 23, from Fife, killed the Staffordshire bull terrier in late April in a “grotesque act of savagery,” the sheriff said.

The dog, which belonged to his friend, had apparently bit his finger causing Graham to snap.

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He initially tried to stab the animal and slit its throat, the BBC reports, but then was caught on CCTV filling up a container with petrol before taking it to Kirkcaldy’s Dunniker Woods and setting it alight.

Graham pleaded guilty to causing the dog unnecessary suffering by causing his death and also admitted a further charge of an attempted knife robbery on 2 May. He was sentenced to 36 months – three years – for his part in the robbery.

Sentencing, the sheriff said: “He went about this in a calculated manner - it wasn't a spur of the moment thing.

“This was a grotesque act of savagery. You will be disqualified from keeping animals for life.

“The sentences will run consecutively - the total will be 45 months.”

The dog, named Bruno, was still alive when he had been set slight, a post-mortem revealed, the Dundee Evening Telegraph said.

Bruno’s owners, Christopher McMahon and Chermaine Letham said that Graham “should be left to rot.”

“If he can do that to a helpless dog then what can he do to a child or elderly person?” Ms Letham said. “Alastair Graham is an evil man.”

Under the Animal Health and Welfare Act, Graham faced a maximum one-year sentence for the killing.

Defending, Larry Flynn, said: “This was a serious offence but he has co-operated with the process throughout.

“He has a vague recollection of doing this but was abusing alcohol at the time.

“His recollection is that he attempted to kill it with a knife but he failed and he went to get the petrol then returned.”