The $500,000 production hit a snag when principal Alex Derbie, of Queenstown, pulled out last week because of ill health.
Director Stephen Robertson contacted Auckland performer Paul Ross to play the roles of Old Gus and Bustopher Jones.
"I hadn't seen Cats for years and only had three days to get it all down," Ross said yesterday.
"But the company has been great to work with and I can't wait to get on stage now."
Dunedin Operatic had sold only a quarter of its ticket allocation - about 4200 - to the musical by late yesterday, which was creating uncertainty about future productions.
"If we lose money on this we won't be able to absorb the loss and put on new shows over the next couple of years," marketing manager Lynda Wright-Sear said.
"When you've got such a big budget for a show like this, it really puts the pressure on to get people along."
Dunedin Operatic plans to stage Miss Saigon in 2010.
"But we need to spend a lot of money soon to secure the rights to Miss Saigon," Dunedin Operatic stalwart Gladys Hope said yesterday.
"We need to know that people still want these big musicals in Dunedin. Are they going off theatre?" It wouldn't be Cats without some drama.
The Andrew Lloyd Webber musical had a troubled start when it premiered in London's West End on May 11, 1981.
Dame Judi Dench (Grizabella) ruptured a tendon and had to be replaced by Elaine Paige.
Cats went on to become London's longest-running musical, until Les Miserables in 2006.
