7 Dec 2021
RVC research reinforces the conclusion of the Metropolitan Police that there was no human involvement in the mutilation of the affected cats.
Joshua Silverwood
Job Title
New research from the RVC has indicated foxes may have been responsible for a spate of mutilated cats found dead in London between 2014-18.
Published today (7 December) in Veterinary Pathology, the research reinforces the conclusion of the Metropolitan Police that there was no human involvement in the mutilation of the affected cats.
Following the mutilation of more than 400 cats across various locations in London during the four-year period, media speculation suggested a human “cat killer” may have been at large in southern Greater London, within the M25 and, later, across the whole of England. Some feared the alleged killer could become a threat to human safety.
The speculation, driven largely by concerned members of the public, led the Metropolitan Police to launch an investigation into the mutilations, named Operation Takahe.
A team of researchers led by Henny Martineau, head of veterinary forensic pathology at the RVC – alongside both the Metropolitan Police and Hertfordshire Police – examined the bodies of 32 mutilated cats that had been brought to police by members of the public between 2016-18. The RVC veterinary pathology team has previously been involved in a range of high-profile criminal cases.
Dr Martineau and her team took swabs to analyse carcases for the presence of fox, dog and badger DNA, and performed full postmortem examinations of the carcases.
The results found a clear link between cat carcase mutilation and the presence of fox DNA on the carcase.
A clear association was also seen between puncture wounds (consistent with scavenging by carnivores) and the deceased cats.
No evidence supported human involvement in their mutilation, with evidence from puncture wounds suggesting 10 had been predated by a carnivore.
Through a close examination of the carcases, Dr Martineau and her team were also able to establish that the mutilation pattern of the cats examined was similar to the scavenging pattern of foxes on lambs. For carcases not associated with predation, other probable causes of death were also identified – ranging from road traffic collisions, to liver failure, to the ingestion of antifreeze.
Eight of the deceased cats were found to have suffered from cardiorespiratory disease in life.
Dr Martineau said: “As veterinary professionals, we know how difficult it is for an owner when a beloved pet passes away, particularly in circumstances that can seem mysterious or suspicious.
“While the public’s concern around the safety of their pets is totally understandable, our investigation into the deaths of these cats demonstrates the importance of an evidence-based approach to investigating incidents like this.
“The narrative of the so-called ‘cat killer’ was a good example of the human tendency to pick out what we want from data, demonstrating our inclination to stop investigating when we think we have made a major discovery or noticed a particular pattern.
“It is the job of scientists – in this instance, veterinary pathologists – to identify and overcome such confirmation bias.”
Chief Insp Stuart Orton, of Hertfordshire Police, said: “This is of course an incredibly emotive subject and any injury to, or loss of, pets causes a lot of distress for owners. While the subject was a matter of much speculation at the time online, we now believe there was no human involvement.
“I hope that this new analysis provides some comfort to the owners who previously believed their beloved pets had been targeted maliciously. It also provides law enforcement colleagues with the ability to review any future investigations from a scientifically supported and evidence-based approach.”
