Oskar Lang's heritage was German-Hungarian. He was born in 1921 in the town of Neu-Werbass in Austria Hungary. His early schooling was there and later in a boarding school in Tuzla, Yugoslavia. The Lang family owned Zoologische Handlung, a business in Belgrade handling many species of exotic animals. It followed logically that Oskar would attend veterinary school and then integrate his profession with his family's interests and activities. To that end, he attended the School of Veterinary Medicine at the University of Vienna during and after World War II, his choice of profession exempting him from military service.

Many things changed after the war. Neu-Werbass became Novi-Vrbas as the area was incorporated into Yugoslavia, the family enterprise was confiscated by the Yugoslavian government, and Oskar found himself cut off from his family. He and fellow students were reduced to killing and eating horses from the school to survive. In 1948, fate intervened in the form of an American named Lillian Metz who had joined the new Marshall Plan program being organized in Europe. Oskar and Lillian were married in Vienna and after several years moved to San Francisco where Oskar worked in a veterinary hospital and honed his English language skills.

In 1961, the Langs moved to Davis where both obtained career positions with the University. Oskar took over the Animal Science small animal colony revitalizing it and expanding it to include breeding colonies of rats, rabbits, mice, and guinea pigs. The colony became known on campus and beyond as one with the highest standards of animal care, providing quality animals for researchers in endocrinology, genetics, and nutrition. Oskar held a Lecturer title for much of his 23 year career and played a major role in teaching laboratory animal care and use to undergraduate and graduate students. He was highly regarded by all who knew him, not only for his professional dedication and skills but also for his unfailing courteous and warm personality. His many friends were saddened by his death at the early age of 63 following long-standing heart problems. A scholarship for Animal Science students interested in laboratory animals has been named in his honor.