The five-time GRAMMY winner, who was recently diagnosed with a respiratory infection, cancelled her Oct. 6 show in Manchester, New Hampshire and her Oct. 7 show in Albany, New York.
The news was shared on Twain's Facebook page on Tuesday. According to the post, the singer's doctors "have advised her to rest for several days."
The bad news gets worse for Twain's fans -- the cancelled dates can't be rescheduled due to her "current touring schedule," but tickets will be refunded.
"Shania Twain apologizes for any inconvenience this may cause her fans and greatly appreciates their understanding," the post explained, adding that the tour will resume Oct. 9 in Quebec City.
Here's more on Twain's farewell concerts: