Technical annual report 2000-01
Dept. of Regional Development, Primary Industry, Fisheries and Resources technical annual report; Department of Regional Development, Primary Industry, Fisheries and Resources technical and annual report; Reports; PublicationNT; Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals
Dept. of Primary Industry and Fisheries
Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295
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Department of Primary Industry and Fisheries 76 PROJECT: Disease Surveillance Project Officers: D. Pinch, Veterinary Officers and Stock Inspectors Location: NT Wide Objective: Provide credible disease surveillance information to support the sale of livestock and livestock products Investigate the occurrence of diseases in Northern Territory livestock Participate in national animal health surveillance programs. There are several areas of activity that contribute to the successful implementation of this project, and they are discussed separately below. Disease surveillance encompasses: the collection of animal health data during disease investigations initiated by the producer (passive surveillance); planned surveys to target a specific disease (active surveillance); providing NT information as part of national programs to enhance Australia's trading status; maintaining a secure and reliable computer system to store and retrieve the data; and communication of results to relevant parties. Hydatid survey DPIF carried out a survey in 2000 to gather information that would determine if hydatid cyst infection, caused by the tapeworm Echinococcus granulosus, occurred in NT-bred cattle. The information can be used to substantiate claims of hydatid cyst freedom in NT cattle for trading purposes. The prevalence of hydatid cysts in the NT has been reported as low. Surveys conducted over 30 years ago in abattoirs reported no evidence in cattle or pigs slaughtered in Darwin and an incidence of 2% in Alice Springs. No surveys have been conducted since then in the NT. Submissions over the past few years to Berrimah Veterinary Laboratories (BVL) have identified hydatid cysts in livers from cattle. Although these have been traced back to animals bred outside the NT, this survey was conducted to confirm that a cycle had not established involving NT-bred cattle. No surveillance has been conducted in the NT for the presence of E. granulosus adults in dingoes or dogs, or for the hydatid cysts in wallabies/kangaroos. As a first step in confirming that E. granulosus does not cycle in the NT, surveillance of cystic lesions in cattle killed at the abattoir in Katherine was conducted between June and September 2000. All cyst-like lesions in the liver and lungs of cattle were collected and submitted to BVL for microscopic and histological examination to determine whether they were hydatid cysts. Records of the property of breeding for the cattle examined were an integral component of the survey, and brand details for each animal were recorded as they entered the killing area. A total of 4,348 animals were examined, 84% of which were NT-bred. The remaining animals were from Queensland or had brands that could not be read. The cattle came from 62 properties, mainly in the northern half of the NT. As expected, the survey found hydatid cysts in cattle imported from Queensland. The prevalence in Queensland-bred animals was 5%. Out of over 3,500 NT-bred animals, only one was linked to a hydatid cyst. Due to sampling problems on the day that cyst was collected, it cannot be confirmed that the cyst came from an NT-bred animal. Follow up work will be conducted to confirm if this is a sampling error. Even if this cyst was from an NT-bred animal, the prevalence would only be 0.03%, which provides strong evidence to support the lack of an established E. granulosus life cycle in the NT. Johne's disease zoning The veterinary committee introduced formal zoning for bovine and ovine Johne's disease (JD) to Australia on 1 August 1999. There are four zones for both bovine and ovine JD: free, protected, control and residual. The NT is a protected zone for bovine JD.