Dr. Dennie grew up on a farm in eastern Washington, where he was exposed to caring for horses, livestock, dogs, and cats. He received a BA degree from the University of Washington and he attended veterinary school at Washington State University, where he received his DVM degree in 1984. He moved to Northern California after graduation and worked in a mixed animal practice for the first three years of his veterinary career. He found that he enjoyed the small animal side of practice the most and spent the next 32 years at a small animal practice in Woodland, the last 24 years of that time as practice owner.

He and his wife Angie raised their daughters Emma and Faith in Woodland, and then moved to Truckee in 2020 after retiring and selling his practice. In 2022 he got the itch to practice veterinary medicine again so he joined the team at HSTT, where he does mostly spay and neuter surgeries one to two days a week.  He loves living in the mountains and in his off time he like likes to ski (both downhill and cross country), hike, road bike, work out at the gym, and travel.