Hydatidosis of cattle and sheep, its economic importance and <i>Echinococcus granulosus</i> among stray dogs in South Wollo, Ethiopia

Abstract

In this crossectional survey the prevalence, fertility, size of hydatid cyst in cattle and sheep, economic losses due to hydatidosis in cattle, and prevalence of Echinococcus granulosus in dogs were studied in South Wollo, Ethiopia. for the purpose Each animal carcass was inspected carefully, hydatid cysts of each organ were counted, measured and examined microscopically to determine the fertility and determination of infection of Echinococcus granulosus in the dog involved in the study was done by standard post-mortem procedure. Of the total of 312 cattle and 197 sheep examined 56 (17.95%) and 15(7.61%) were found to be infected with hydatid cysts respectively. The prevalence in cattle tended to be high, though the difference was not statistically significant (P> 0.05, X²=1.006). Lung was found to be the most commonly affected organ in case of cattle, liver in case of sheep with a value of 66.25%and 82.36% respectively. Spleen and heart were found to be less commonly affected organs in cattle and lung in case of sheep, cysts were not observed in the kidney in both species. Studies on the condition of the cysts revealed that medium sized cysts predominate in case of cattle with an abundance rate of 54.9%, followed by small cysts (40.8%) and large cysts (4.3%). All of the cysts found in sheep were small and majority of them showed calcification. Cyst fertility rates were 36.2% and 45.5% in lung and livers respectively (z = 0.46, P = 0.643). Out of 10 stray dogs euthanized and examined at necropsy 2(20%) were found to be infected with adult E.granulosus with a mean worm burden of 30. An annual loss of 464,900 Eth.birr was estimated to be caused by bovine hydatidosis from organ condemnation and carcass weight losses. In conclusion this zoonotic cestode need deserve due attention in order to safe guard the public and reduce the economic losses in animals, thus relevant control measures  pertinent to the prevailing socioeconomic factors in the area were recommended.

Keywords: Cattle, Echinococcus granulosus, Ethiopia, Hydatidosis, Prevalence, Sheep