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Resistance of gastrointestinal nematode worms to anthelmintic drenches has led to new tactics for treatment of worms in sheep. Regional, calendar-based drenching programs have been replaced with programs designed for individual farms, which are based on measures of worm burden, drench resistance and genetic resistance of sheep to worms. To support these new worm control strategies, the Australian Sheep Industry CRC is developing improved on-farm and laboratory tests to measure worm burdens and the genera of worms present in parasitized sheep. Rapid identification of parasitic worm burdens are: Dipstick assay for Haemonchus contortus infection and the use of worm-derived molecules in faeces for diagnosis (presence in faeces of antigens released from parasites: H. contortus, Teladorsagia (Ostertagia) circumcincta and Trichostrongylus colubrifomis). Rapid identification and quantification of worm egg genera are: Quantitative estimation of the number of worm eggs in faeces (worm egg counting) and rapid identification of worm egg genera. Automated systems for measuring weight loss caused by worms and for diagnosis of covert blowfly strike are under development by the CRC. Managing parasites on an individual sheep basis rather than a flock basis is likely to contribute to maximising the efficiency of sheep enterprises as well as assisting in the sustainability of parasite control. A test for diagnosis of Haemonchus worm infections on-farm is currently under field trial in the lead up to commercial release in 2006.