The 36-year-old, who had two wins on the feeder Web.com tour in 2008 and played 121 U.S. PGA Tour tournaments, was diagnosed with leukemia as a teenager and suffered a relapse in 2012.
After a second relapse last July, he had a third stem cell transplant before returning to hospital in May.
"Earlier today, Jarrod made the decision to stop active treatment and begin palliative care," Briony Lyle posted on Facebook under a picture of the golfer in a hospital bed hugging the couple's two young daughters.
"He has given everything that he’s got to give and his poor body cannot take any more. We'll be taking him closer to home in the next couple of days so he can finally leave the hospital."
Briony Lyle asked for the media to respect the family's privacy and said she would post details of a memorial service for her husband when appropriate.
(Reporting by Nick Mulvenney, editing by Peter Rutherford)
