Spontaneous primary intrathoracic, extrapulmonary hydatid cyst in a broiler rabbit

Echinococcus granulosus, a zoonotic tapeworm with a dog-herbivore life cycle, is known to use ruminants, horses, pigs, etc., as intermediate hosts. Natural infections of hydatid cysts have not been documented in small animals like rabbits in India. This paper records spontaneous intrathoracic, extrapulmonary hydatid cysts of E. granulosus in a cage reared rabbit. The presence of non-invasive unilocular cyst with typical protoscolices containing rostellar hooks favoured the diagnosis of E. granulosus over E. multilocularis, the only other Echinococcus species found in India. The presence of fertile hydatid cyst points to the fact that rabbits can also act as natural intermediate hosts for E. granulosus. The significance of the findings in relation to public health importance is discussed.