The 31-year-old had struggled with a knee injury for the whole of 2018 and had been unable to add to his 120-game tally.
"My body sort of let me down a little bit this year. I've had some issues and it was a hard decision," Spurr said.
"I've loved my time at the club. It's really hard to say goodbye and I wish I could play on, but for me, my knee is telling me it's time for me to go, and I've been battling with that all year."