Dennis received his BS degree in biology from Bluffton College where he was a Pi Delta honor student, and in his senior year was the recipient of the A. C. Burkey Athlete of the Year Award and May Day king honor. He later received his Masters Degree in botany from Bowling Green State University.
He taught biology for five years in high schools and a junior college in Ohio and Maryland. He later taught real estate principles and practices at University of Findlay.
After teaching biology, Dennis and his wife Jan managed real estate rentals in Findlay, and with his father-in-law Dr. Kandel owned and operated Bishop-Kandel Realty which they sold in 1981. Today he is involved with the ownership and management of over 300 residential and commercial properties in Findlay.
In 1986 Dennis and his son Bruce began a grain farming operation and currently own and farm 4,000 acres. He is also co-owner of DLM Plastics which is a dielectric heat-sealing plastic and vinyl company located in Findlay.
Dennis has been involved in many community organizations. He is past president of the local real estate board and Findlay Rotary, as well as past chairman of the board of Blanchard Valley Regional Health Center.
Dennis and his wife have done extensive traveling and have invested in real estate in Nicaragua and Panama. His wife is a professional harpist and they have three married children.