The decapitated animal was found by its owner in the Shirley area of Solihull, West Midlands, last Thursday
An RSPCA spokeswoman said: “The owner, who is too distraught to speak to the media, found her 18-year-old cat decapitated in her back garden. The male black cat was very friendly and trusting. His body was found at 5.30am.”
RSPCA inspector Boris Lasserre said: “I am almost lost for words about this despicable act of cruelty.
“Our priority is to warn other cat owners in the area about what has happened and to appeal to people’s consciences if they know who may be responsible.
“It is important to stress vets believe someone has been responsible for this offence; due to the clean cut it is not possible that an animal has attacked the cat.
“I appeal to anyone who has seen anything, whether on a social media site or witnessed anything suspicious, or anyone that has heard something locally, to please get in contact with me. We must catch the person responsible.”