Aidan O’Brien said at York on Thursday that the virus that has played havoc with his season is as bad as he has suffered during his 20-plus years at Ballydoyle.
O’Brien saddled a world record 28 Group One triumphs last season but this campaign, despite achieving another eight winners at the highest level, has been affected by sick horses in all three yards that make up his stable in County Tipperary.
And he is conscious that if the bug resurfaces then his season would effectively be over.
“It’s probably as bad as we’ve got [had] in Ballydoyle, but it happens,” he said. “I’m not complaining because it happens to everybody [at some stage]. It just got in and got through the place.
“There are so many variables that everyone has to deal with - and that’s what makes every year and horse different. You have to play it the way it comes.
“Sometimes the ducks come all in a row and sometimes they don’t, but you have to be patient. The lads are all patient and there’s no pressure.”
Explaining the nature of the problems he has faced, the champion trainer said: “They weren’t scoping clean. It went right through all the yards and everything got it.
“It’s like phlegm or pus in your throat, an upper respiratory thing. It went through the whole place and it’s the same as a human having the flu. Some you can work your way gently with and some you have to pull back and go easy.
“We were lucky in that they worked away, but at the time you have to be easy on them to let them get over it. And when you are being easy they might not be as fit as you would like.”
Some of O’Brien’s horses have run to form and on Thursday he achieved his first Lowther triumph via the tenacious rally of Fairyland. However, others have run well below-par and the sequence of unpredictability has been going on for some time.
“It’s not one size fits all,” O’Brien said. “Some can be fine and some don’t do as good as others.
“We do everything in our power (to prevent it) but it’s a thing that will carry in the air. If you are 50 or 100 yards it will blow with a sneeze.
“I think we are at the other side of it now but because we were very gentle on the horses for those months they’ve probably lost a good bit of fitness that they’d usually have at this stage of the season.
“They are coming back and the year is not over yet. There’s plenty of racing but we have be patient - take it race by race and then horse by horse.
“And the important thing is that it does not relapse because if that happens the season is over.”