Alastair Graham was looking after Bruno, a Staffordshire Bull Terrier cross, for a friend when he snapped after the animal bit his finger.
He tied Bruno to a tree in Kirkcaldy's Dunniker Woods and initially attempted to slit its throat and stab it to death.
But when he failed, Graham went to a nearby petrol station and filled up a jerry can before pouring it over the terrified dog.
He then set the dog alight - causing horrific burns to the defenceless animal.
A sheriff told Graham the attack was a "grotesque act of savagery".
In accordance with the Animal Health and Welfare Act under which he was prosecuted, Graham could only be jailed for a maximum of a year - and his early guilty plea meant only nine months of his 45-month sentence is as a result of the brutal killing.
However, he was jailed for a further 36 months over an attempted robbery committed with his friend Steven Gourdie days after the fire attack.
Fiscal depute Susan Dickson told Kirkcaldy Sheriff Court that a post-mortem examination on Bruno revealed the animal had still been alive when Graham had set him alight.
She said: "At around 2pm on April 25 a dog walker saw a black object around 10 metres from a path - he looked more closely and saw it was the remains of a dog."
She said the police were initially unable to trace the owners, but later received information about their identity.
She continued: "On April 28 the owner met Mr Graham and brought the story about the dog being found up on the TV.
"The accused initially said 'that's sick'. They went into the kitchen and Mr Graham then said 'it was me'.
"A post-mortem on the dog was carried out which revealed the burning was concentrated over the neck, head and thorax areas, with the right side badly burnt to full thickness.
"There was a thick black deposit round the neck consistent with the harness - the metal parts were burnt on to the neck. There was inhalation of smoke in the dog's airways which indicates it was alive when it was set on fire.
"The accused, when interviewed, said he had taken the dog for a walk but it had run away."
Graham, 23, a prisoner at HMP Perth, pleaded guilty on indictment to causing Bruno unnecessary suffering by causing his death in the fire on April 24 or 25.
He further admitted an attempted knife robbery committed alongside Gourdie, committed on May 2 at High Street, Leven.
Larry Flynn, defending Graham, 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."
Sheriff James Williamson jailed Graham for 45 months in total - nine months for the dog attack and three years for the robbery.
Gourdie will be sentenced for the robbery on August 1.
He 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."
Bruno's owners, Christopher McMahon and Chermaine Letham, branded Graham "evil" and the maximum sentence "disgusting".
Ms Letham said: "Alastair Graham is an evil man. If he can do that to a helpless dog then what can he do to a child or elderly person?
"His maximum sentence is a joke. He tortured and murdered a family pet simply because he bit his finger.
"That's disgusting. He should be left to rot."
She added: "When I found out about Bruno and the terrible way he had passed, my heart was broken. Bruno was a very loving and caring dog who enjoyed long cuddles. He was so gentle around children and was also good around other dogs."