Gloucester lock Slater retires at 33 after motor neurone disease diagnosis
Slater made three appearances for Gloucester last season as they finished fifth in the Premiership. He joined Gloucester in the summer of 2017 from Leicester Tigers, where he was the captain for two seasons.
Gloucester said Slater's diagnosis was confirmed last week following six months of testing and that the club are committed to supporting him and his family.
"With the support of his family, friends and Gloucester Rugby, he has made the difficult decision to retire from professional rugby with immediate effect," Gloucester said in a statement.
"While Ed, his family and the club take time to determine next steps, Gloucester Rugby have opened a JustGiving page.
"The direction of these funds will be determined in due course, whether it be supporting Ed and his family directly and/or a selected MND charity."
World Rugby chairman Bill Beaumont offered his support to Slater and his family.
"The thoughts of everyone at World Rugby are with Ed Slater, his wife and his children at this very difficult time," Beaumont tweeted. "Rugby is a family and we will do anything we can to offer support and comfort to Ed & his family in any way we can."