A pet dog was tied up with electrical flex and set alight, leaving it so badly burned that in some places its bones have been exposed.
Ozzie has a 50% chance of surviving the ordeal
Ozzie, a two-year-old Border Collie, was found by the RSPCA wandering in Bedminster, Bristol, with burns to his face and body.
Owner Pauline Kaines said: "When I saw him I just broke down - I still cry now to see him in so much pain."
The animal has burns to his eyes, ears, genitals and sides.
He has been given a 50-50 chance of surviving the ordeal.
Michael Kaines, Pauline's husband, had gone out to buy fish and chips on Thursday, leaving Ozzie at home.
When he returned the dog had disappeared.
"When I saw him on a drip with all the burns on him I just could not believe it," he said.
Pauline added: "It's just horrific how anyone could do that to an animal, I don't understand it - they're not human, I hate them - they're sick people to do that to an innocent animal."
Glyn Roberts, from the RSPCA, said: "Something like this is deliberate.
"We will take those responsible to court if we find them."