The fire broke out just after 2 p.m. PT in the large barn near the All Seasons Mushroom farm on 224th Street.
Jackson Wittup, the executive director of Harness Racing BC, said JJJ Stables owner Rick Mowles and Bill Davis, the horses' driver and trainer, are devastated.
"Rick breeds his own horses, so most of these were probably all home bred that he raised, picked the matings to be born and saw some of them born, and probably has watched them ever since their career started," he said.
"So this is going to be very very tough on him financially and emotionally. And Bill Davis too, he was making a very nice living with those kind of horses."
Wittup said the industry is already short of horses in Western Canada and North America.
"So when you take 17 quality horses like this right out of the mix too, it's not good for the industry, but again it is so much worse for the horses' owner and trainer and all their connections."
Possible electrical fire
Wittup said investigators are working on the theory that it was an electrical fire, but a definitive cause is far from being established.
He said the two men are "really shook up" and hopes they can recover and remain in the industry.
"The biggest thing is the standardbred industry and all horsemen of all breeds are very very strong and resilient, he said.
"They try to beat each other every night on the race track when they are racing. But if somebody is out and needs some help, they will all be there for them then. I know I haven't been near the phone for an hour or so, but I know there will be all forms of fundraising and different kind of things to help out."
At the height of the fire, about 11 trucks and more than 40 firefighters were on the scene as thick black smoke could be seen from several kilometres away.
Google maps: 3300 block of 224 St., Langley, B.C.