It was unusual to see horses passing Zurella in the closing stages of her race.
"After she cooled off she started coughing," said Ritchie.
"She came back to the birdcage with sand on her belly and Craig had mentioned the track was a bit loose, so what I'm hoping the scan will show is that she might have swallowed some sand and got a raw throat."
Ritchie said it would surprise him if the problem turned out to be a virus because Zurella's vital signs had all been perfect going into the race.
"I was actually quite confident she could win and she just doesn't run bad races like that."
Ritchie said it was nothing new, but it was nonetheless a reminder how quickly you could go from hero to zero in major Australian carnivals.
"When she won the Let's Elope I had 200 text messages of: 'where are you going for dinner tonight?'
"There is nothing more sobering that getting your arse kicked over here.
"This time I had two text messages, from my mother and my wife, and they have to get in touch."
Ritchie said he would now remain in Melbourne this week until Artistic runs at Moonee Valley on Friday night.
"Zurella can run in the Turnbull Stakes next and that will tell us where we are for the spring.
"If it's not the Caulfield Cup then there are plenty of mares' races."
The Naturalism Stakes was won by Folding Gear, a Caulfield specialist.
The 5-year-old by Johar, trained at Seymour by Lee Hope and son Shannon, won the group two Autumn Classic (1800m) in February last year and the Easter Cup (2000m) in April before Saturday's win over 2000m, reports the Herald Sun.
Shannon Hope said the stable had been patient with the gelding and, depending how he recovered from the race, he would be aimed for the Caulfield Cup on October 20.
"He is an underrated galloper. He doesn't need a lot of racing and he may not have another run before the Caulfield Cup," he said.
Former New Zealander Mr O'Ceirin, who looked certain to win in the home straight, ran second with Matamata stayer Single Minded dropping away to beat one home after getting back then working hard to get up to the leaders mid-race.
