"I got back from Sydney early June and decided to take on the role as foreman at his Serpentine-based Perth stable. He has around 40 in full training with two pre-trainers providing a continuous turnover of fit horses.
"I grew up attending Petre Pony Club from age 5 to 12. My mother Petrina was a president. I had many riding lessons from the late Ken Cropp before track riding at the Wanganui racecourse for Mr Cropp and my father Bill before school."
After moving to Pukekohe at the end of 2005, Lewthwaite rode trackwork before high school for the likes of Craig Richie and Steve Goodin.
Leaving school on the eve of the 2007 Australian equine influenza, his first full time job was working for Nigel Tiley at the IRT Blackbridge Qurantine Station in Karaka looking after the large backlog of New Zealand-bound horses from Australia under strict MAF qurantine procedures.
"In 2009 I went back to high school to gain the requirements to study a degree in communication which I did not finish due to an opportunity to work in the production of The Hobbit films as a horse wrangler and riding double, travelling the whole of New Zealand playing different roles as dwarfs and elves in many of the riding scenes in the three movies.
"It was a once in a lifetime opportunity that showed me the entire country. It gave me the urge to travel and further boosted my passion of working with horses."
In between filming breaks Lewthwaite spent time working for Hastings trainer Paul Nelson riding steeplechasers at his farm in Hawkes Bay.
In June 2012 he travelled to Europe on a holiday, which included a week in Newmarket and attending the premier July Cup meeting in hopes of witnessing the great Black Caviar. However, she was scratched and returned home after Royal Ascot Diamond Jubilee win.
"From Europe I returned to Perth where I began working at thoroughbred studs focusing on my horsemanship and yearling preps before getting back into my true passion - racehorses.
"Enjoying an eye-opening season working for ex-jockey Vaughn Sigley, I built some great relationships with well-respected owners and veteran trainers that have set my heart firmly in the west.
"The climate for training racehorses here is obviously a lot different, especially in the summer when the state is like a desert. Over the last christmas we had nearly 100 days without rain and nuisances like snakes and huge amounts of flies that change the priorities of managing a horses well-being.
"I really enjoy it here and I'm very excited about joining the Harrison stable. David has a true wealth of knowledge and I'm looking forward to learning more from his experience and the success he has had training horses in this part of the world.
"With the new season beginning in just a few weeks my goal is to do all I can to help the Harrison team climb the ladder towards the top of the 2014/15 Perth Trainers premiership," Lewthwaite said.