"He has hunted, played polo and showjumped -- you name it. He's done one-day and three-day eventing, riding club -- everything you can do here, so we come from a very traditional base.
"I'm an ex-chemistry person so I have got an analytical mind that has to understand everything and find a scientific reason for everything," she explains.
The pair's introduction to bit-less riding came about in sad circumstances when a friend died, leaving behind a much-loved, but somewhat unruly horse that became very difficult to ride.
"Toddy was a big beautiful grey Irish Draught, but he was really angry," recalls Trish.
"He would pull at the bit, duck his head down, snatch at the reins and was getting bolder every day.
"He had some serious behavioural issues. In fact, Tom used to say he was the only horse he could look in the eye and still be run away with -- he would turn his head right round and stay galloping away from you.
"We gave him to other people to ride, to make sure it wasn't just me, but he would rush at fences and take off on landing, no matter who was riding him," says Trish.
The first tactic was to change the bit in his mouth. "We used a pelham with a curb chain and a flash noseband -- I had a lot of artillery!" she laughs. "But he still got the better of me."
The climax came one day when Trish hacked out on the beach and, after popping two breakwaters calmly, Toddy dived to the right and took off, head up in the air, heading towards Carlingford and out to sea.
"I was roaring and pulling like a demon and eventually managed to run him into rocks to stop him. I nearly vomited with the fright," recalls Trish.
What followed was a weekend of deep thought, soul-searching and internet research. "To me, Toddy was not logical, there had to be some reason for his behaviour -- that was the chemist in me breaking out," she explains.
Her search brought her to a UK website promoting bitless bridles, as well as the US version, where she read every paper written by Dr Robert Cook.
"There was a questionnaire that examined 10 signs of facial neuralgia [nerve pain] and I could tick eight of the 10 boxes.
"I spent another day studying the information before I brought my 'findings' to Tom, who looked at me as if I was off my head completely!" she says.
Undeterred, Trish ordered two bridles over the internet, one in Toddy's size and the second to use on another horse, almost as a scientific control.
"The first time I rode Toddy in, he didn't put his head down or try to bolt, anything like that," she says.
"I went away and came back an hour later to ride him again. There was no pulling, no chucking at the bit, it was as if someone had turned off a switch."
Gobsmacked by the horse's behaviour, Trish turned to Tom, and the resident riding instructor, and asked them to ride and see if they noticed a change.
"Everyone noticed something -- his head carriage was different, his trot was lighter. There was no rushing into a jump and no running away after the fence.
"My only thought was 'Holy God what's going on here?'"
Utterly converted, the Ridgeways trained every horse in the Dillonstown yard to bitless bridles and haven't looked back.
"It took years off some of the older animals. Suddenly we had 20-year-old ponies jumping a metre -- ponies that would have been narky and contrary started jumping for fun," enthuses Trish.
Soon after, a chance remark about 'the next step' from a UK bitless bridle instructor led Trish to examine the merits of working horses barefoot.
"I looked it up on the internet and discovered a whole barefoot movement in America based on studies by a farrier called Jaime Jackson," she explains. The studies were based on the wild mustang herds of the American plains.
"Anytime we shod a horse for the first time, our own farrier, Ivor Winters, would mutter something about it being the beginning of the end," she says.
It turned out Ivor was also of the opinion that shoeing a horse was compromising the big engineering master plan of nature.
"Ivor has a real respect for the horse's hoof and encouraged my curiosity and research into the barefoot issue."
The pair hatched a plan to experiment on a draught horse, named Charlie, that Trish had bought when he was destined for the factory, after a long period of injury. Ivor trimmed his feet as best he could, and Charlie was given a reprieve of a few months for his feet to toughen up.
In the meantime, Trish's research led her to an expert in barefoot hoofcare not far from home. Remedial podiatrist Dermot McCourt is based in Castlewellan, Co Down, and has worked and trained in Saudi Arabia and with several AANHCP (Association for the Advancement of Natural Horse Care Practices) practitioners in the USA.
Although his initial training was in traditional farriery methods, he now specialises in working with severe foot problems, such as navicular syndrome and laminitis, as well as being an expert in barefoot trimming.
"Dermot came down and looked at what Ivor had done and between the two of them they got Charlie's hooves like marble," says Trish.
Now, Charlie and the other barefoot horses are ridden on every surface from stones to gravel, sand, water, tarmac roads and laneways.
"Don't get me wrong -- it's not like they can be ridden straightaway. They need to go through a transition phase first, to allow their feet to toughen up," she warns.
"They can be a bit 'footy' for a few weeks and the feet need to find an equilibrium.
"We couldn't go ballroom dancing in flip flops, so we have to give them a chance first. The most demanding part of working barefoot is patience and taking expert advice."
Castle Horses have recently moved to Dunany Estate, although the Dillonstown yard is still regarded as home for the AIRE-approved equestrian centre. Both yards feature what must be one of the most unique riding experiences in the country: barefoot and bitless.