A retrospective survey of hydatidosis in livestock in Shiraz, Iran, based on abattoir data during 1999-2004

Meat inspection records in an abattoir located in Shiraz, a city in southwest Iran and the capital of Fars province, during a 5-year period from 20 March 1999 to 19 March 2004 were used to determine the prevalence of hydatidosis in sheep, cattle, and goats in the region. A total of 844,039 animals (cattle 131,716; sheep 577,090; goats 135,233) slaughtered in the 5-year period and overall 34,856 (4.1%) livers and 123,402 (14.62%) lungs were condemned. Hydatidosis was responsible for 28.7 and 15.4% of total livers and lungs condemnations, respectively. The overall trend for all livestock and in both organs was a significant downward one. The annual prevalence of liver condemnations due to hydatidosis was decreased from 2.1, 1.8, and 1.0% in 1999-2000 to 0.62, 0.33, and 0.20% in 2003-2004 for cattle, sheep, and goats, respectively. The corresponding features for lung condemnation due to hydatidosis were relatively higher than liver, declining from 3.0, 4.6, and 4.4% in 1999-2000 to 1.3, 1.5, and 0.56% in 2003-2004, for cattle, sheep, and goats, respectively. Greater awareness among farmers, destruction of organs containing hydatid cysts, prevention of access of dogs to raw offals and implementation of national rabies control program could be responsible factors. Data showed significant seasonal pattern for hydatidosis in all species. Liver condemnations due to hydatidosis were higher in the spring and summer for sheep, whereas lung condemnations were higher in summer for both sheep and goats. Liver and lung condemnations in cattle were higher in winter. This could be attributed to various factors such as sources of slaughtered animals, changes in management practice and ecological factors. The overall trend was relatively the same when annual condemnations were adjusted for the effect of seasonal variation. The present survey provides baseline data for the future monitoring of this potentially important parasitic disease in the region.