Deranged boyfriend Sebastiano Mauro went to a stable and slashed his ex-lover's horse in a revenge attack after their affair ended with his arrest for an alleged assault.

Mauro, a surgical nurse, used a sharp bladed instrument to attack the ten-year old bay coloured mare called Jessie.

Sicilian Mauro slashed a deep cut on the inside of the horse's right hind leg that left the bone visible and blood pouring from the wound.

He made off from the farmyard, but later a stable girl discovered the distressed horse bleeding heavily and a vet was called to treat the animal.

But Mauro's campaign of terror against Jessie's owner, Nathalie Kelderman, 36, was far from over.

Two months later, after being released on bail from prison where he had been held following the attack, he turned up outside South African Miss Kelderman's flat.

When given bail, 43-year-old Mauro had been warned he must not go anywhere near her home in St Albans, and stay out of Hertfordshire altogether.

But three days after his release, he drove from his mother's address in Chatteris, Cambs and parked in a side street close to Nathalie's home.

Determined to attack her once more, he was armed with a carving knife, two screwdrivers, scalpel blades, a tourniquet, latex gloves, empty syringes and two syringes containing his own blood.

Luckily, two police officers concerned he might try and get to her discovered him yards from her flat and once more he was arrested.

Today (Wednesday) at St Albans Crown Court Mauro was jailed for five years by a judge who told him: "Given that you were on police bail to then visit the stables was particularly unpleasant."

He was found guilty by a jury of a charge of taking revenge on her by attacking her horse and going equipped for burglary intending to inflict grievous bodily harm on her.

Passing sentence, Judge Stephen Gullick told Mauro, of Heronshaw Close, Chatteris, Cambs: "You had clearly with you a knife or sharp object and you took out your annoyance on that animal, which was very close to the heart of your ex-girlfriend. It was a particularly nasty offence."

The judge said that weeks later, Mauro again flouted conditions of his bail by going to Nathalie's home armed with a variety of frightening items, including a knife and scalpel blades.

He told him: "The jury have decided your purpose in going there was to cause her very serious bodily harm."

In addition to passing the five year sentence, the judge made Mauro the subject of a prohibition order forbidding him from going anywhere near his ex or her horse.

During the trial the jury heard how Mauro met blonde-haired Miss Kelderman through an internet dating agency in early January 2011.

He was a divorcee with two children and within days he and Miss Kelderman had embarked on an intense and passionate relationship.

George Heimler, prosecuting, described the affair as "tempestuous" and said by the beginning of July he was dividing his time between his mother's home in Chatteris and Miss Kelderman's flat off Holywell Hill in St Albans.

The court heard how on Monday, July 4, last year the couple left the flat and went for a walk in Verulamium Park to feed the ducks and play with a frisbee.

Miss Kelderman, an office worker, told the jury they were sitting on the grass talking when a jogger and his dog passed by. Nathalie and the runner had exchanged pleasantries before and he said hello.

She said: "I greeted him by smiling and said hello back to him. He carried on jogging past with his dog and at that Sebastiano got quite upset.

"He said: 'How dare you greet another man like that, how dare you humiliate me like that in public.' He grabbed me by my arm and yanked me and threw me on the floor and pinned me down on the floor, shaking me and shouting at me.

"Then he got up and as he walked past me he kicked me in the right foot and said 'You would make an excellent f****** whore.'

She said as he stormed off he called her a f****** bitch, but the court heard there was another incident outside her flat a short while later when he chased her, and a motorist accidentally drove into him causing a minor injury to his knee.

Police were called to the scene and Mauro was taken to Watford General Hospital where he was later arrested.

While police were waiting at the hospital to speak to him, he sent Miss Kelderman a text message which read: "They want to arrest me. Think about what you are doing. This could ruin my life."

The jury heard that having been charged with assault, he was released on bail with a condition not to have any contact with Miss Kelderman. Even so, he turned up at her flat trying to persuade her to drop the charge against him.

She later informed the police of his visit.

Days later on the afternoon of Monday, July 11, Mauro drove his black Chrysler car to the stables at Little Munden Farm in School Lane, Bricket Wood, where he knew Miss Kelderman kept her horse, Jessie, a bay mare, standing at just over 16.1 hands.

He had been there before with her to watch her ride and knew the stable where the horse was kept.

CCTV cameras caught him making his way to the stable where he was seen to go inside before leaving soon afterwards.

Stable groom Michaela Crossley was in the stable yard later that afternoon and noticed a bag of hay had been moved from outside Jessie's stable and went inside to investigate.

She was shocked to discover the horse was bleeding heavily from a deep finger-length cut that ran vertically on the inside of Jessie's lower right hind leg and exposed the bone.

Vet Christopher Blackmore who was called to the yard described it as an "incisional type wound" with straight edges that was bleeding heavily.

"It gave the impression of being caused by a sharp object," he told the court and he said he used forceps to stop the bleeding before applying stitches and bandaging the leg.

The stable where Jessie had been was checked for any sharp objects and nothing was found.

Tenant farmer Andrew McClelland said: "I went into the stable for a look and in the middle amongst the wood chip was quite a pile of blood. It was as if the horse had just stood there in the middle and hadn't moved the whole time it was bleeding."

Miss Kelderman said when she found out her horse had been attacked she phoned Mauro.

"I wanted to know if he had been anywhere near my horse. He didn't say either way. I told him the yard manager was saying Jessie had a serious cut and he said 'How can you believe that I have cut your horse - you know I love animals," she said.

Mauro, she said, even offered to use his surgery skills to stitch Jessie's wound himself saying she didn't need anyone else.

He was arrested at his mother's home later that day after the farm's CCTV footage had been looked at and he had been recognised as the person going to the horse's stable.

He remained in custody at Bedford Prison until Friday, September 9, when a crown court judge freed him on bail with strict conditions that he have no contact with Nathalie and stay out of Hertfordshire completely.

But three days later police officers checking on Nathalie's welfare discovered Mauro in the street outside her flat with a black bag and an assortment of items including a knife, gloves, a scalpel and blades and blood filled syringes.

There was a large amount of blood on a pair of jeans and T-shirt he was wearing and once more he was arrested and taken into custody.

In the witness box Mauro, a trained nurse who worked as a surgeon's assistant at a private hospital in Bushey, denied assaulting Miss Kelderman in the park.

He admitted he had felt "belittled" when she had greeted the jogger and he agreed he had said she would "do well on the game" because he was annoyed.

Mauro claimed he had gone to the stables hoping to see Miss Kelderman the following week and had taken with him five carrots for Jessie.

He said on finding the horse in the stable he fed her one and stroked her before leaving.

Mauro then claimed that weeks later when he was eventually released on bail from prison, he had "stupidly agreed" during a phone call with his ex to go to her flat and collect an address book of his that was still there.

He said at the time he had been taking samples of his own blood because with his job he had to have his blood screened at a lab every three months.

Mauro said he had got blood on his jeans and T-shirt during the process.

He said when he set off for her flat, the syringes containing the blood were in his car.

Walking up to the flat, he said he had the syringes with him for safe keeping and claimed that Miss Kelderman had met him in the street outside and handed him a bag containing his address book and other property into which he had put the syringes.

He said after she had gone back to her flat he was making his way to his car when the police arrived on the scene and he was arrested.

It was a story the jury rejected and as Mauro was led from court to begin his sentence South African born-Nathalie said Jessie had made a full recovery from the injury.