Owners have been advised to keep their cats indoors after a series of gruesome attacks on animals.

Pet welfare experts believe a sharp instrument was used to inflict horrific injuries on Theresa Platts' 13-year-old tabby, Crumble.

Two other cats have been found with their heads chopped off.

Crumble was found lying in Wiston Walk, Brighton, with a 3cm-diameter wound to her internal organs.

Brighton and Hove City Council's animal welfare office had received an anonymous phone call alerting them to Crumble's plight.

Animal welfare officer Amanda Teal, at first assumed Crumble had been hit by a car.

However, staff at the Coastway Veterinary Group practice in Montague Place, Brighton, raised concerns the injuries were suspicious.

Veterinary surgeon Bronwen Eastwood, said: "There were no other signs of injury other than this penetrating stab wound.

"There have been several scientific papers recently on suspicious attacks on animals and this definitely matched those descriptions."

Crumble was transferred to the PDSA Veterinary Clinic in Robertson Road, Brighton, for treatment. She was allowed to return to Mrs Platts' home in Whitehawk Way on Friday.

Mrs Platts said: "She seems to be getting better, considering what she has been through. It has made her very nervous, though.

"It just horrifies me that someone could have done this. They must be really sick.

"I just want other people to be aware of what has happened so they can take extra care of their animals."

Ms Teal said: "Hopefully this is just a one-off, though people should be on the look-out."

Mrs Platts reported Crumble missing on October 23. She was found later that day but was not reunited with her owners until the following week.

One of the headless cats was found in Portslade on Wednesday last week, a few days after a similar grim discovery in Hove.

Sergeant Steve French, leading the police investigation, said: "Finding the bodies was extremely distressing.

"A vet has confirmed the cats' heads were cut off. Whoever did this must have been soaked in blood and we need people who saw anything to contact us."

The RSPCA is also investigating the attacks. A spokeswoman said: "Even if the incidents are unrelated, they are all very worrying to us."

Anyone with information should contact police on 0845 6070999.