The long-serving medical officer of health for Windsor-Essex has decided to retire.

Dr. Allen Heimann, who has worked for the health unit for the last 25 years, will remain on until the end of the year.

Tecumseh Mayor Gary McNamara is the chairman of the health unit's board of directors.

"He's like a walking encyclopedia, medical encyclopedia. (He is a) very knowledgeable individual when it comes to communicable diseases. He's an authority," said McNamara.

McNamara says the board started working on a succession plan four years ago.

It led to the hiring of Dr. Gary Kirk as CEO.

Kirk will keep the title of CEO when he moves into the medical officer of health role.

"He's young, and we foresee him being a long-tenured member of the health unit team, and over the last two-and-a-half years or so, he's been mentored by Dr. Heimann," said McNamara.

Heimann said he'll be returning to private practice.