Back to State Outlooks

South Australia worms, flies and lice update - February 2019

SA WormBoss Worm Control Programs

SA WormBoss Drench Decision Guides





Adelaide: Colin Trengove, Sheep Health Lecturer (UA Roseworthy campus) (

Apart from a welcome 20–40 mm in December, the protracted dry spell since last spring has continued across most of South Australia. Bursts of exceptionally hot weather in January and February combined with sparse ground cover should have minimised worm pickup, but mob worm burdens will depend on the preceding drenching/worm management programs. In contrast, time spent on flystrike management will have been minimal.

Recent monitoring has indicated a continuance of the typical wide variation seen over summer in weaners and ewes alike. Perusing over 100 worm egg count (WEC) results from around South Australia during January/February indicates two-thirds of mobs had burdens high enough to warrant a summer drench. Lamb counts up to 2,800 eggs per gram (epg) have been detected in the south-east and older ewes across the State have commonly had counts in the 100s epg. This highlights that seasonal conditions are not a useful predictor of worm burdens and monitoring in individual mobs is an essential strategy for effective parasite management.

Significant worm burdens (>100 epg) in young and old alike should be addressed to limit worm infestations in winter. The choice of drench will depend on the level and spread of drench resistance in particular flocks, however, drenching with at least 2 or 3 chemical actives in a combination is always recommended.

The exceptionally low rainfall in 2018 in most of the State has led to water quantity and quality issues for livestock. Carting water is a common practice in many districts, but water quality also needs to be monitored. Scours in livestock during summer can be indicative of several conditions: worm burden; bacterial infection; liver or kidney diseases/toxicities; or water quality issues such as high salt content, bacterial contamination, high organic matter, stagnation, or algae blooms. When water is scarce, it is essential to check potability to ensure your precious livestock remain healthy and productive.

For February 2019 state outlooks, please follow the links below:
Back to State Outlooks