Queensland Derby hopeful Sonntag is literally the horse that keeps on giving.

The Riding for the Disabled Association (RDA) of Australia will benefit from Sonntag's trip to Brisbane for the Queensland Derby via a host of fundraising activities surrounding the horse.

Sonntag's owners will auction the chance to become one of the three-year-old's owners for the day with the highest bidder earning flights, accommodation and members' enclosure passes at Eagle Farm.

The winning bidder will also get a $250 each-way bet on Sonntag while the charity will receive five per cent of any prize money the Henry Dwyer-trained stayer wins in the Queensland Derby.

"They (RDA) do a phenomenal job in Australia and they don't get the recognition they deserve," part-owner, RSN radio host Shane Anderson, said.

"When they idea came up, the owners were very quick to put their hands up and do it, which is terrific."

But Sonntag was a long way from racing, let alone competing in a Queensland Derby, when he suffered a tendon sheath infection soon after Dwyer bought him from Darley at a mixed sale in August last year.

Dwyer had Sonntag gelded soon after he arrived at his stable but a minor wound picked up in the spelling paddock threatened to cost his new owners more than the $58,000 they paid for him.

"He was acutely lame in his near hind leg and they found a small puncture wound in the back of his pastern and that became infected," Anderson said.

"They had to rush him into surgery to flush out the tendon sheath and it was a 50/50 chance that he will be able to come through it."

The operation was successful, leaving Sonntag able to resume racing and recoup his purchase price as well as the early vet expenses in just four starts.

Sonntag scored in dominant fashion at his last outing on May 17 to earn a chance to become the first Group One winner for Dwyer, who has had his licence for less than a year.

"Henry has done an amazing job to find the horse then get him to a stage where we can even think of running him in a Group One race," Anderson said.

Sonntag is a $14 chance to provide a five-figure windfall for the RDA.