The third phase of the animal research debate started around 1950. After World War II the government became a major sponsor of scientific research, including biomedical research. The budget of the National Institutes of Health (NIH) grew dramatically and has continued to grow, with a few minor retrenchment periods, up to the present time (see Figure 1). This growth led to an enormous expansion in publicly funded research. In the private sector, the discovery of penicillin and streptomycin led to a tremendous expansion in pharmaceutical research and in the size of the prescription drug industry. These expansions in government funding for biomedical research and in private-sector investment in drug discovery created an increase in demand for laboratory animals.
Rowan, A.N., & Loew, F.M. (2001). Animal research: A review of developments, 1950-2000. In D.J. Salem & A.N. Rowan (Eds.), The state of the animals 2001 (pp. 111-120). Washington, DC: Humane Society Press.