He attended high school in Feldkirch and from 1796 to 1798 he studied medicine in the University of Freiburg, where he received a master's degree in surgery.

[2] Schädler fought as a member of the 20-man Liechtenstein volunteer corps against the French during the War of the First Coalition, where he was wounded in 1797.

[2] He was the first academically trained doctor in Liechtenstein and opened his own medical practice in Eschen in 1801, later in Nendeln.

Schädler was the first doctor to provide obstetrics and train midwives in the country, as well as treat poor sick people and royal officials in addition to medical examinations for the Liechtenstein military.

[2] In 1842, he retired to Bendern with his son Karl Schädler taking over his medical practice, where he died on 20 November 1842, aged 66 years old.