"This means that people with the heavier style of horse, which would not be viable in a modern show ring, can take part in our events, because we use 'typing' to separate the different styles of miniature horse into their own classes."
The show will include all three "types"; foundation, classic and modern, and the competitions cover handling, grooming and turnout, registered and unregistered classes and in-hand and harness dressage and trail classes where the horses are led over and around obstacles.
The miniatures also compete in in-hand jumping classes, with the handlers running alongside.
"There's been a resurgence of interest in miniature horses of late, and with the new classes including the older-style horses, people are getting out again and competing and having fun," says Jackie.
"It's fun to watch - these little horses can do anything a big horse can do, but to scale. It's a great day for people to come along and watch, ask questions and maybe consider joining the club."
Jackie became a miniature horse owner when she retired from riding horses.
"I thought 'what am I going to do now?' and I did some research and bought my first mini. The first of 22. They are addictive and once you start, you want to collect the set," she laughs.
"They are great for people who no longer want to own a huge horse, they are a perfect way for children to learn about horses and gain confidence and they become part of the family. Minis are very trainable and you can work with them as much as you want."
The East Coast Miniature Horse Club Summer Slam Show starts at 9am on Saturday and Sunday, March 25 and 26, at Golden Oaks Equestrian Centre, Mangaroa Rd, Hastings. Spectator entry is free.