BROOKFIELD, Wis. (CBS 58) -- The Brookfield Police Department is asking for the public's help in locating a missing 78-year-old man. 

Police have issued a silver alert for Douglas Dunning, who they say went missing from his residence after leaving for a walk and was last seen by his wife. 

Dunning is described as being 5-foot-8 inches tall, weighing 161 pounds, with brown eyes and brown balding hair. 

He was last wearing a long sleeve burgundy polo shirt, grey slacks, and white Nike tennis shoes. 

Police say Dunning was last spotted near Mayfair Drive and North Avenue on Friday, August 1, at 8:30 p.m.

He is believed to have dementia or some other cognitive impairment. 

If located, you're asked to contact the City of Brookfield Police Department.