An RSPCA officer said he was still in shock yesterday after finding a dog burned alive while tied to a tree.
Simon Davies, West Midlands region RSPCA inspector, described the attack as horrendous and premeditated.
The animal's charred remains were discovered at the edge of Handsworth Golf Club in Handsworth Wood, Birmingham, last Wednesday and reported to the organisation by a passer-by.
The Staffordshire bull terrier was found tied tightly to a tree by his lead on a patch of open land off Silvercroft Avenue.
He was wearing a nylon muzzle, a distinctive black leather harness, embossed with a brass pattern and a tan leather collar with brass studs.
He had a wound on the top of his head and a large can, the same shape as a de-icer canister, was found beside his remains. A large area of ground around the animal had been scorched by fire.
It is thought the contents of the canister - carpet upholstery glue - had been sprayed on the dog and set alight.
The burns suggested it had been set alight on both sides, passed out and fallen onto one side. The uppermost side was found still smouldering.
"What makes this crime so horrible was the fact it was premeditated," said Mr Davies.
"Someone has left their home and taken this equipment with them along with the dog with the full intention of carrying out this horrendous and sadistic act."
He said officers were keeping an open mind as to who may have committed the act but suspected it was probably done by his keeper.
The dog's expensive harness and collar tended to suggest that it was at some stage prized by its owner.
"I have a feeling that the person who did this is the person who was in charge of the dog rather than it being a dog who was stolen," said Mr Davies.
"This is not someone not being able to feed their dog properly or who did not have money to take the animal to the vet.
"That person no longer had a use for it and they have decided to set fire to it."
He said he was still in shock about the discovery. "How many people have burned themselves on a grill pan or a hob when they have been cooking and thought that hurt? Imagine the pain this dog has gone through.
"I find it difficult to put my thoughts into words after removing his charred body. I simply can't comprehend what could motivate someone to inflict such appalling pain and suffering to a living creature."
Revealing further details about the "sickening discovery", Mr Davies said: "It is my opinion that this dog was alive when he was deliberately set alight.
"He was tied to the tree so tightly that I had to use a knife to free him. Particularly upsetting is that I believe the dog was set on fire wearing a muzzle to prevent him from barking.
"I also believe whoever carried out this heinous act knew the dog would be found at this spot as it's often used by dog walkers. A more secluded spot could certainly have been found but this was not the intention of the person responsible."
Mr Davies added: "I would urge anyone with any information, no matter how insignificant it might seem, to please get in contact with me.
"If people know of someone who owned a Staffordshire bull terrier that has not been seen for a while or who recognise the distinctive harness, I would appeal to them to get in contact."
Anyone with information can contact the RSPCA cruelty and advice line in confidence on 0870 5555 999.