"We were coming off the farm and I still wanted that contact for Charlie because he enjoyed being around animals.
"That was one of the reasons. But animals have healing powers, and also physically it helps with his mobility, his core strength and all his co-ordination."
The benefits don't stop there.
"It breaks down barriers for communication. His language has developed and he's more confident giving verbal instructions to the horse and also in communicating with the staff and other riders. There's also the freedom that riding gives you - he really enjoys it."
Sharon says Charlie is a confident rider.
"He sits on his horse very proud and I have to say he's got a very good seat - he is quite a good rider and I would like to see if it was something we could take further with him. I think he would fit into regular riding lessons with his ability."
Sharon says Charlie is very capable and wants to be part of everything that's happening around him.
"Last year he played tackle rugby. He's into everything and wants to have a go at everything. Yes, he has Down's syndrome, but he's very capable and enjoys life and being part of what goes off."
Sharon says as Charlie gets older there is an increasingly noticeable physical gap between him and his peers.
"He adapts things so he can join in, but with riding he doesn't have to do any of that, so I think the riding breaks down any physical barriers too."
RDA's Jo Grace, who is in charge of fundraising and marketing, says the organisation is desperately in need of volunteers to maximise its work.
She says Tauranga RDA is currently running with two thirds of its normal volunteer numbers. From a normal base of around 120 volunteers, there are now 80.
They are essential to keep the programmes running.
"Depending on how many rides we have on in each class - we could have four or five riders in a class - and they may need, depending on their disability, up to three volunteers per horse," she says.
Classes are run five days a week and about 150 riders ride each week.
Currently, because of the heavy demand, riders are there once a week on a term on, term off basis "so everyone gets a chance", and there is a "massive" waiting list.
Because of the lack of volunteers, adult riding is currently on hold.
Jo says volunteer don't necessarily need to be "horsey" people.
"A lot of people say they don't know anything about horses, but volunteers need to just be someone that's reliable who wants to be part of a really good team and just be able to turn up.
"It's a little bit physical because they do need to be able to walk around a lot of the day and help with the children sometimes mounting and dismounting, but the biggest things are being reliable and having empathy."
Jo says there is a mix of volunteers from those who are still at school, retired people and people who are between jobs.
"Some people don't actually want to be working on the rides either - they may want to go out the back and help with stable work and we have one volunteer that does admin work.
"They find it's a real community. They have lunch together and quite often they go away at the weekends and do things together, so it ends up being quite a nice community feel."
Jo says volunteers can be at the complex for as much time as they can give.
"If they can do a day, that's awesome, but half a day is great as well. Mostly they need to be here at least half a day to get the most out of it."
Programmes only run during term time.
"We always invite people up here to have a look around, watch a ride and see if it actually suits them."
• Anyone interested can email admin@taurangarda.org.nz or call 07 544 1899.