Livestock parasites

Parasites are a major cause of disease and production loss in livestock, frequently causing significant economic loss and impacting on animal welfare. In addition to the impact on animal health and production, control measures are costly and often time-consuming. A major concern is the development of resistance by worms, lice and blowflies to many of the chemicals used to control them. 

Planned preventative programs are necessary to minimise the risks of parasitic disease outbreaks and sub-clinical (invisible) losses of animal production, and to ensure the most efficient use of control chemicals.  Integrated parasite management programs aim to provide optimal parasite control for the minimal use of chemicals by integrating pre-emptive treatments, parasite monitoring schedules and non-chemical strategies such as nutrition, genetics and pasture management. 

The Department of Primary Industries and Regional Development provides recommendations for the most effective approaches to the control of the major parasites of livestock

Articles

  • The impact of parasites on sheep can range from being virtually undetectable, through to obvious clinical signs or even death.

  • Sheep farmers can save money and time eradicating new lice infestations by taking simple biosecurity measures that become part of normal management programs.

  • Itch mites are small, barely visible parasites of sheep; they live on the skin surface and cause rubbing and fleece chewing in a small proportion of infested animals.

  • A summer drenching program for sheep worm control is now recognised as a key cause of drench resistance in Western Australia.

  • Gastro-intestinal worm infections in sheep are a major cause of lost productivity to the Western Australian (WA) sheep industry and control has become more complex due to widespread drench resistan

  • The most common lice affecting sheep are body lice (Bovicola ovis).

  • Barber's pole worm (Haemonchus contortus) is a potentially harmful roundworm parasite of sheep which can cause a disease called haemonchosis.

  • Flystrike is a significant health and welfare risk to Australian sheep and costs $280 million annually.

  • Nasal bots are the maggots or larvae of the sheep nasal bot fly, Oestrus ovis.

  • Hydatid disease is a serious human health concern, caused by cysts of the tapeworm parasite Echinococcus granulosus.