Jonathan McRae and Dayle Pike with some of their horses on their Manawaru property.

Two Waikato horse trainers are being forced out of their home and business after years of unexplained attacks on their property and animals.

Over the past 12 years, Jonathan McRae and Dayle Pike have had to put at least eight horses down due to unexplained injuries, including cuts, needle marks, leg tendon injuries, stabbing and poisoning.

They have also experienced hundreds of incidents of vandalism to fences, water troughs, horse covers and their horse truck.

Supplied Jonathan McRae and Dayle Pike's horse Meomyo, was a potential jumping prospect before it was found with fluid leaking from it's left knee from a needle sized hole.

Their Manawaru home has been broken into many times, with jewellery stolen and clothes and curtains vandalised, and fruit trees and vegetables had also been sprayed with poison.

Their dogs, cat and chickens had also been injured in what they call attacks of intimidation, including a shot rat left under the door mat.

Pike said she found her rooster with 2m of bailing twine threaded through its neck, when it was still alive.

Supplied Signs of needle scarring across race horse Meomyo's knee joint were found once the hair was removed.

"It was really frightening," she said.

The pair have no idea who carried out the attacks, which started happening in 2004.

They have reported incidents to police, Ministry for Primary Industries, the New Zealand Racing Board and New Zealand Thoroughbred Racing, but investigations have so far been fruitless.

McRae said he slept in the stable for four months to try to catch the vandals. The pair had installed security cameras, but they only recorded flashing torch lights.

"They knew the camera was there," he said.

The couple said they were now "just about bankrupt" and their reputation as horse trainers was "shot".

"We're going to sell, we're getting out of it. We've been running circles for 12 years, there's no point staying here," McRae said.

The pair have ridden horses since they were children and are "heartbroken" to be forced out of racehorse training.

Pike said the ongoing attacks had been very upsetting for them and other family members.

"It was very stressful. We've been driven off our property, we're heart broken," she said.

"We don't know what to do, this is our life."

McRae bought the property in the 1980s and developed it into a purpose-built, horse training facility, complete with a riding track, lunging ring, horse walker and stables.

"We've got everything we need there but they've forced us out," McRae said.

JUMPING PROSPECT PUT DOWN

The racehorse Meomyo was one of eight horses that had to be put down over a 12-year period due to unexplained illness and injury.

McRae said the potential race mare, owned by the couple, was found with fluid leaking from it's left knee from a needle sized hole in July, 2014.

The thoroughbred was lame, so the knee was shaven at the leakage site a week later because the mare's condition had not improved.

Two circular marks were observed, so hair remover was then used on both knees to determine the extent of the abnormality, he said.

"The left knee had the signs of needle scarring across virtually the entire knee, joint capsule, and the right knee did not display any marks and the skin was unblemished," he said.

Over a period of time, the mare's knee became arthritic with the onset of lameness and had to be put down, he said.

"In July, 2014, our three jumping prospects had their race careers permanently extinguished over two nights due to debilitating injuries being caused."

One horse, Traditio, had needle marks observed on the back of left fore tendon when the leg was shaven in preparation for a veterinary scan.

The other horse, Ira Bean, was struck across the right hind in the stable overnight, causing extreme lameness. A large circular gouge was found at a later date to the outside of the right hind cannon bone.

Neither were put down due to their injuries.