DANE COUNTY, Wis. (CBS 58) -- Dane County authorities have issued a Silver Alert for Robert Joseph Aeschbach, a 77-year-old man who left to pick up medication at a pharmacy in Waunakee on Friday, June 5 at around 12:10 p.m. and has not been heard from since.

His family suspects he may have Alzheimer's disease.

Aeschbach is described as a white man, 5 feet 9 inches tall, 180 pounds, with green eyes, gray balding hair and a mustache. He reportedly has difficulty walking and scars on his knees from knee replacement surgery.

He is believed to be driving a blue 2017 Ford Escape with Wisconsin license plate AHN7000.

Anyone with information is asked to contact the Dane County Sheriff's Office at (608) 255-2345.