Dr. Marvin and Betty Nielsen

Dr. Marvin L. Nielsen, 91, of Tucson, AZ, passed away peacefully at home on February 19, 2026. Marvin was preceded in death by his beloved wife, Betty, 85, on September 29, 2025. Marvin was a loved husband, father, grandfather, friend, and Veterinarian; Betty was a cherished wife, mother, grandmother, and friend. Their presence will be deeply missed. Marvin was a U.S. Army veteran and graduated with a Doctorate in Veterinary Medicine from Iowa State University in 1962, practicing veterinary medicine in Iowa for 11 years, and another 45 in Tucson. He was equally compassionate with the large animals and pets he treated and their humans who loved them. Marvin enjoyed golf, as well as landscaping and maintaining his property and celebrating family. Marvin and Betty (Rustvold) wed June 22, 1958, in Audubon, IA, sharing 67 loving years together. Marvin and Betty enjoyed spending quality time with family and friends and following University of Arizona men's basketball. Betty was an avid, excellent bowler and athlete, playing forward for the Audubon High girls basketball team; she enjoyed hosting and celebrating family holidays, decorating the family home, and spending time in social settings with her friends.

Marvin and Betty are survived by their son, Rod Nielsen (Connie), daughter Joni Borboa (Beau), both of Tucson, and sons Scott Nielsen (Ann), of Alexandria, VA, and Brett Nielsen (Denise), of Barnes City, IA, sixteen grandchildren, and multiple great-grandchildren.

A celebration of Betty's life was held in October 2025. Marvin's life will be celebrated in a memorial service at the Our Lady of the Desert All Faiths Memorial Park, 2151 S Avenida Los Reyes, Tucson, AZ, on Monday, April 6, 2026, at 11:00 AM. In lieu of flowers, please consider donating, in Dr. Marvin Nielsen's memory, to the Humane Society of Southern Arizona in Tucson.