Echinococcus granulosus in dogs and sheep in central Utah, 1971-1976.

During 1971 to 1976, a survey was conducted to determine the prevalence of Echinococcus granulosus infection among dogs and sheep in central Utah. For each year, the number of dogs positive for adult tapeworms of the total number examined and the percentage infected were: in 1971, 14 of 51 infected (27.4%); in 1972, 13 of 46 infected (28.3%); in 1973, 7 of 36 infected (19.4%); in 1974, 34 of 244 infected (13.9%); in 1975, 13 of 267 infected (4.9%); and in 1976, 14 of 195 infected (7.2%), or a 6-year total of 95 of 839 infected (av = 11.3%). For each year, the number of sheep positive with hydatid cysts of the total number examined and the percentage infected were: in 1971, 103 of 1,007 infected (10.2%); in 1972, 235 of 1,808 infected (13.0%); in 1973, 242 of 2,003 infected (12.1%); in 1974, 105 of 1,406 infected (7.5%); in 1975, 96 of 1,599 infected (6.0%); and in 1976, 96 of 1,171 infected (8.2%), or a 6-year total of 877 of 8,994 infected (av = 9.8%). These results represent a definite decline in numbers of infected animals and suggest that preventive and control measures advocated in central Utah are being implemented.