The 22-year-old was rushed to hospital on Wednesday after staff at the Lethbridge Correctional Centre in southern Alberta found him trying to hang himself.
Saretzky has been charged with two counts of first-degree murder in the deaths of two-year-old Hailey Dunbar-Blanchette and her father, 27-year-old Terry Blanchette. There is an additional charge of committing indignity to a body involving the girl.
Hailey's body was found last week in a rural area near Blairmore, a day after her father was discovered dead in the southern Alberta town of about 2,000 people. The case sparked an Amber Alert across Western Canada and Montana.
Saretzky is scheduled to appear in court on Wednesday.