In 1974 the Executive Committee of the Vancouver Regional Branch of the B.C.S.P.C.A. began investigating factors that influence the pet population. Specific attention was given to the changing sociological environment of the area as well as techniques for the control of the pet population and its growth. Some of the sociological problems found in the survey were as follows. Massive increases in multi-unit dwellings such as condominiums and apartment blocks had changed the living space available for both humans and animals. In addition, the actual role of the dog in society had changed in many instances. People were choosing larger dogs to fulfill the role of both pet and guard dog. Dog sizes increased over five years from 22.4 pounds to 51.8 pounds.
Homes, Jack, "Comprehensive Animal Control" (1985). Management and Control of Companion Animal Populations. 8.