"We had a rider yesterday that was very upset that Tinks was away because we can't operate with her because she's sore so she's out of the programme, so we've had to use other horses," Benson said.
Mann said the horses at RDA were all assigned to certain riders by their body types, meaning the riders scheduled for Tinks on Wednesday had to be assigned to a different horse.
That change was not always easy for some kids, she said.
"Something as simple as a dart going into a horse, it's changed a few lives because they can't ride their horse so now we have to explain and redirect that, and for a child who doesn't understand what's happened it's really hard, and it's like a domino effect because it affected their day," Mann said.
The two RDA staff said the dart incident had made Tinks more apprehensive towards humans.
"She [used to] go up to anybody in a loving way, and to have someone do that, it does kind of make them a little wary, so today she was a little wary of us coming near her, so it's affected her," Mann said.
RDA doesn't know who was responsible for injuring Tinks, as it happened either on Tuesday night or the early hours of Wednesday morning when the grounds were unattended.
"We're going to be looking at doing some fundraising to get some additional cameras, maybe in some blindspots, we didn't think we'd ever need them but now, maybe," Mann said.
Benson said they had contacted the police about the incident.
Between April and June, the horses at RDA were disturbed by a drone flying at a low level over their grounds, sometimes when children were riding them.
