Melbourne Cup-winning Hunter-based syndicators Australian Bloodstock may focus more on NSW features in the wake of new Racing Victoria restrictions on runners in their premier event.
And Australian Bloodstock director Luke Murrell fears the rules will lead to no overseas-trained runners in the Melbourne Cup.
A raft of changes were announced on Wednesday after Racing Victoria endorsed 41 of 44 recommendations of a review into the race's high injury and fatality rate, especially among imports.
The rules include restricting international horses to one lead-up run in Australia and capping their numbers at Werribee International Quarantine Centre to 24. In 2018, 42 were at the centre.
The internationals must also have "full body scintigraphy and CT/MRI of their distal limbs at the expense of their connections two to six weeks prior to entering pre-export quarantine". They must also "be available for a further pre-export test from an RV-appointed vet, before having to comply with a number of pre-race tests while in quarantine".
Australian Bloodstock, which claimed the 2014 Melbourne Cup with German-bred and trained Protectionist, have long focused on buying proven overseas stayers to target the race but Murrell said the changes may force a "slight rethink".
"It won't affect us from a business point of view, we will continue to buy them, and there's plenty of races to run in here," Murrell said.
"If anything, we might look to run a few more of them in Sydney. Melbourne might drop off in terms of interest. Sydney is trying to take Melbourne on and they have put on a number of rich races, so we might go that way."
He said his company usually had "one or two, and another fringe player" on the chartered flight to Australia each year chasing the Cup but "this will affect that because they are cutting the numbers to 24" at Werribee.
He said Australian Bloodstock already "do over and above" the most stringent tests when buying horses but the new rules provided further uncertainty for owners.
"Previously you could buy them and have certainty you will be in the race," he said.
"Now you can have, as has been the issue in the past couple of years, the horse's vet or treating vets in other parts of the world saying this horse is sound, then the Racing Victoria vets say the horse is not right for our race and you're not in it. It's just an uncertainty from an owners' point of view."
He said it would be impractical in some cases to have the required scans done before buying a Cup hope.
"I wouldn't let a potential buyer pick up my horse, put it on a float and take it somewhere and do those tests," he said. "These horses are in work and if I don't buy it, they are probably running in two weeks, so you don't want, in some instances, a 16-hour round trip to do them."
Given the new rules, Murrell said "I'll be staggered if any European-trained horses come" for the Cup.
As for the required scintigraphy and CT/MRI scans, he said: "I don't know if there's a horse in training that would pass them."