Cesar Ruiz, 19, was booked into the Jefferson Parish Correctional Center on one count of attempted first-degree murder in the case.
According to the sheriff's office, the young child had been hospitalized since Oct. 16 with breathing problems and was set to undergo surgery on Oct. 31.
A spokesman said detectives were called to Ochsner Hospital Sunday afternoon to check on a report that a two-month-old in the hospital's pediatric ward had a blood alcohol level of .289.
Detectives said that around 11:30 a.m. Sunday, while undergoing treatment, the child began having seizures and was moved to the Pediatric Intensive Care Unit where his elevated blood alcohol level was discovered.
Under questioning, the sheriff's office said Ruiz admitted that when he and his wife went home to shower, he took one of his son's feeding tubes and upon returning to the hospital, poured rum into the tube when he was alone with the child.
The spokesman said Ruiz told detectives that he poured the rum into the tube to try to ease his son's suffering and not in an attempt to kill him.