Hydatidosis is a widespread zoonosis infecting a large number of
   animals and humans. Human hydatidosis is a common disease in different
   parts of Iran especially in Hamadan province. Many cases of cysts are
   operated every year in regional hospitals. Animal echinococcosis
   prevalence was determined by necropsy examination of viscera from
   domestic slaughtered animals, including sheep, goats and cattle.

          After inspecting viscera for hydatid cyst, unilocular cysts produced by
   E. granulosus were recovered from 212 out of 2000 domestic herbivores
   (1547 sheep, 333 cattle and 120 goats) slaughtered  in Hamadan abattoir.
   The number of cyst of different organs was counted and their diameter was
   measured. Thereafter, by dissecting the cysts, the volume of hydatic fluid
  was measured, and their fertility was determined by finding protoscoleces
   and the number of protoscolex per/ml fluid was counted.  

          The frequency of presumptive liver/abdominal, lung, and liver-lung
   hydatid cyst was 15.3% (51/333), 10.6% (159/1547) and 1.7% (2/120) for
   cattle, sheep and goats respectively. The fertility rate of hydatid cysts in
   sheep, cattle, and goats recorded as 35.2.%, 23.5% and 0% respectively. The
   huge dispersed slaughtering of sheep for various purposes  and the large
   number of dogs allowed access to the offal coupled to the hundred
   thousands number of sheep slaughtered in Haj Pilgrim days, indicates that,
   the sheep is the most significant host for  maintaining the life cycle of the
   parasite in Iran.

          We demonstrated a high prevalence of animal echinococcosis in this
   mountainous , agricultural province of Iran.