Echinococcus granulosus in farm dogs and dingoes in south eastern Queensland.

Twenty-nine farms with a prevalence of greater than 20% of hydatidosis in cattle were visited in south eastern Queensland between August and December 1982. All farms carried beef cattle but none sheep. Twenty-four had dingoes and wallabies but only 8 had feral pigs. On 17 farms either macropods were killed for dog food or dogs were suspected of hunting macropods or scavenging their carcases. Purge samples were collected from 45 dogs from 23 of the 29 farms visited. The Australian sylvatic strain of Echinococcus granulosus was found in low numbers in purged intestinal content from one dog from each of 2 farms. Also, 50 intestinal tracts from dingoes from southern Queensland were examined between October 1981 and November 1983. The sylvatic strain of E. granulosus was found in 36 dingoes, the Australian mainland domestic strain in 4, and a further 5 dingoes were infected but the strain was not identified. This work indicates that domestic dogs are probably not important definitive hosts for E. granulosus in south eastern Queensland but could be an occasional source of infection for man. Dingoes are the major definitive host and worm numbers can be very high. Small foci of the domestic strain of E. granulosus may be maintained in a cycle involving dingoes, macropods and possibly feral pigs in cattle raising areas of coastal Queensland.