There were 632 known canine programs in 608 separate forces in the United States between 1907 and 1978. Research since 1979 has identified 188 additional programs, of which 160 remain operational. Overall, 510 police canine units composed of about 3,000 dog-handler teams existed in December 1982. Newly confirmed programs for the 1907-51 period were New Haven, Conn., Englewood, N.J., Ridgewood, N.J., Baltimore, Md., and Babylon Town, N.Y. The 188 new programs serve 6 classes of public agencies: city or local forces who have the most canine units; county forces; State police; units created by the Guam and Virgin Islands territorial governments; harbor, transit, housing authority, and parks police forces, and university police. The Los Angeles Police Department and the Los Angeles County Police both implemented police dog programs in 1980. Maine and Tennessee State agencies started units for special patrol purposes. The New York Transit Authority Police put canine units into service in 1980, and that city's parks department instituted a guard dog program in 1982 to combat vandalism. Although canine programs have never been popular on campuses, they have proved extremely useful in patroling property after dark. Canada has 34 operational canine programs as of mid-1982, ranging from the Royal Canadian Mounted Police's 70-team program to provincial and municipal services. Police dogs assist with parks and natural resource patrols in Nova Scotia, the Parks Canada-Western Region, and New Brunswick. The U.S. and Canadian police dog programs have similar missions and are characterized by rigorous and ongoing training and high morale. Both appear to be implementing more units than are being discontinued. Tables and 24 references are supplied.