The patient suffered from severe pneumonia and tissue wounds.
But now, he has a clean bill of health.
Even his flipper wounds have healed.
On Thursday, the patient — a Kemp's ridley sea turtle — returned to the sea, joining other marine animals that were airlifted to Central Florida and later rehabilitated at SeaWorld Orlando.
A U.S. Coast Guard airplane flew the turtles into Central Florida in 2012 after they were were rescued off the coast of Cape Cod, Mass. while suffering from cold stress.
SeaWorld Orlando returned the juvenile Kemp's ridley sea turtle at Canaveral National Seashore on Thursday after more than a year of extensive treatment.
The turtle released Thursday was the final one to be returned from the group of 24 brought to SeaWorld Orlando in December 2012.
"As a result of the cold stress, the sea turtle developed severe pneumonia and suffered from tissue wounds on his neck and flippers," SeaWorld Orlando said in a statement. "Upon arrival at SeaWorld Orlando, the sea turtle underwent extensive treatment, including laser debridement for tissue wounds and a bronchoscopy to examine the lungs."