The 35-year-old has guided the Cherries from League Two to the Championship during two spells as boss.
Howe, who returned to the South Coast club from Burnley in October 2012, has said that he does not take his job for granted.
"I think you always fear the sack," Howe told Bournemouth's official website.
"From the day I took the job to the day we stayed up against Grimsby, those worries have never gone. I might not be in the job this time next year and I've got to constantly prove that I deserve to stay in the job, to build a team and take the club forward.
"The fear of not doing well and not winning games drives me every day. I think as long as I have that inside me all the time, then hopefully we will be successful."
Howe's Bournemouth side currently sit eighth in the Championship.