The 26-year-old centre will switch to English Championship side Ealing Trailfinders having made his debut for the Welsh region in September 2016 against Ulster Rugby.
The South African has made 35 appearances for the Rodney Parade outfit to date, scoring six tries.
Dragons Head Coach, Bernard Jackman commented: “On behalf of the Dragons I would like to thank Pat for all of his efforts in a Dragons jersey and wish him well for the future.”
