Low-Cost Methods For Deworming Goats and Sheep
10.17 -Low-Cost Methods For Deworming Goats and Sheep
Olivia Dailey, University of Guelph, Canada
Related video(s): Stocking fingerlings in a nursery pond (Source: Access Agriculture)
Suggested citation for this chapter.
Dailey,O. (2026) Low-Cost Methods For Deworming Goats and Sheep, M.N. Raizada, University of Guelph, Canada. farmpedia.org
Introduction
Goats and sheep are common on smallholder farms (Devendra, 1980), however all herbivorous grazing livestock (ruminants) will contract a form of parasite at some point in their life (Merck Veterinary Manual, 2023). These parasites can reduce the ruminant's health and productivity by weakening them and slowing growth, lowering milk and meat production, and affecting coat quality, leading to increased veterinary costs and fatalities (Taylor et al., 2016). As a result, parasitic infections in ruminants cause significant economic losses for farmers globally (FAO, 2018). Traditionally, farmers control parasites using chemical deworming drugs (anthelmintics), but repeated and heavy use has led to drug resistance in many regions (Chandrawathni et al., 2003). In addition to this, commonly used dewormers, such as Ivermectin and Albendazole, are becoming increasingly expensive and/or difficult to access, especially for smallholder farms. Therefore, developing affordable and practical low-cost deworming initiatives is vital in order to help farmers manage parasites effectively while managing healthy ruminants.
Common Parasites in Goats and Sheep
Goats and sheep are commonly affected by internal parasites that live in the digestive system, lungs, or liver (Taylor et al., 2016). These parasites are especially common in grazing animals because they are frequently exposed to parasite larvae while feeding on pasture (Merck Veterinary Manual, 2023). The following are some of the most common parasites affecting goats and sheep worldwide:
Figure 1. Haemonchus contortus (Barber Pole Worm) found in the abomasum of a sheep (Source: Merck Veterinary Manual).
One of the most harmful parasites is Barber Pole Worm (Haemonchus contortus), a parasite that lives in the stomach (specifically the abomasum) of small ruminants and consumes their blood, potentially causing severe anemia. Infected animals may become weak, lose weight, and show pale mucous membranes in the eyes and gums. Another common visible sign of severe infection is “bottle jaw”, which is swelling under the jaw caused by fluid accumulation due to protein loss (Taylor et. al., 2016). Young and weak animals are particularly vulnerable, and infections can quickly become fatal if untreated (Merck Veterinary Manual, 2023).
Figure 2. Trichostrongylus (Source: Wikipedia).
Another group of sheep and goat parasites belong to Trichostrongylus spp. and Teladosagia spp. which are gastrointestinal nematodes that infect the stomach and small intestine of small ruminants (Taylor et al., 2016). These types of parasites damage the digestive tract and interfere with nutrient absorption, which can lead to poor growth, diarrhea, reduced appetite, and weight loss.
Figure 3. Liver Flukes in Sheep and Goats (Source: Wormboss).
Liver fluke (Fasciola hepatica) is a flat parasite that infects the liver and bile ducts of grazing animals (Mascoma et al., 2019). This parasite is common in wet or marshy grazing areas and infections can damage liver tissue leading to reduced growth, poor body condition, decreased productivity, and anemia (FAO, 2018). In severe cases, liver damage can cause death. Chronic infections may also reduce the value of livestock products because affected livers must be discarded during meat processing (FAO, 2018).
Figure 4. Lungworms in Goats and Sheep (Source: Worm Boss).
Lastly, Lungworms (Dictyocaulus spp.) are parasites that infect the respiratory system. These worms live in the airways of the lungs and cause irritation and inflammation which in turn affects breathing (Taylor et al., 2016).
Life Cycle of Parasites
Figure 5. The life cycle of Haemonchus contortus in sheep (Adducci et al., 2022).
Adult parasites living inside a ruminant can produce eggs that are passed in the feces (Bowman, 2014). These eggs hatch in the pasture and develop into infective larvae under suitable environmental conditions, particularly in warm and humid climates. When ruminants graze, they accidentally ingest these larvae along with grass or vegetation. Once inside the animal, the larvae develop into adult parasites and continue the cycle (Taylor et al., 2016).
Strategic Deworming Techniques and Their Effectiveness
Effective parasite control in goats and sheep requires more than routine administration of deworming drugs. “Modern” parasite management pivots towards strategic treatment and improved pasture management and hygiene to reduce parasite exposure while maintaining ruminant health. These approaches are important because excessive use of chemical dewormers can lead to anthelmintic resistance, causing immunity in many regions (COMBAR et al., 2022). Studies have shown that parasites can reduce small ruminant productivity by 10–30% in meat and milk production, particularly in tropical and subtropical regions where parasite survival is high (FAO, 2018). Strategic deworming methods aim to reduce these losses while slowing the development of drug-resistant parasites (COMBAR et al., 2022). These are described below.
Targeted Selective Treatment (TST)
In many regions such as Africa and South Asia, limited access to veterinary care makes early parasite detection difficult (FAO, 2018). One effective strategy that allows farmers to be self-reliant is Targeted Selective Treatment (TST), an approach that allows farmers to treat only animals showing signs of infection, rather than treating the entire herd, lowering drug costs (COMBAR et al., 2022).
A widely used tool within this system is the FAMACHA scoring method, a simple and low-cost way to detect anemia caused by parasites that consume blood such as Haemonchus contortus. Farmers examine the color of the animal's lower eyelid and compare it with a color chart that indicates the severity of anemia, animals with pale eyelids are more likely to be heavily infected and should receive treatment (Van Wyk and Bath 2002). Research has shown that TST programs can reduce dewormer use by up to 60–70% in tested regions such as South Africa, while maintaining the ruminants health and productivity (COMBAR et al., 2022).
Figure 6. FAMACHA: A guide to assessing anemia in livestock. (Source: Northwest Livestock).
Rotational Grazing
Rotational grazing is another strategy for reducing parasite infections by moving animals between different pasture areas so that previously grazed fields have time to recover (Taylor et al., 2016). When animals remain on the same pasture continuously, parasite eggs shed in feces can develop into infective larvae that contaminate the grass (Waller, 2006). Some pasture types, particularly short grasses, increase parasite exposure because larvae are concentrated and near the soil surface (O'Conner et al., 2006). Rotational grazing frequency should be adjusted based on environmental conditions with shorter periods in high risk environments (COMBAR et al., 2022). High stocking density increases parasite transmission, so spreading animals across larger areas reduces risk (Waller, 2006). Returning to previously grazed pastures is safer after dry periods as larvae survival declines in dry conditions (Taylor et al. 2016).
Feeding and Holding Pen Hygiene
Maintaining good livestock hygiene is also a low cost method for parasite control. Parasite eggs are typically passed in animal feces and develop into larvae in the pasture environment (FAO, 2018). Cleaning and removing manure from areas where animals congregate, such as feeding areas and holding pens, can reduce contamination. Manure should be stored at least 10-20 meters away from livestock areas to reduce reinfection risk and prevent contamination in grazing zones (FAO, 2018). Studies in smallholder farming systems in Africa and Asia have shown that poor pasture management can increase parasite burdens by more than 50%, leading to significant productivity losses (FAO, 2018).
Low-Cost Alternative: Copper Oxide Wire Particles (COWP)
Another low-cost method for controlling parasites is the use of Copper Oxide Wire Particles (COWP) (Burke & Miller, 2008). These small copper particles, typically containing 2-4 grams of fine copper wires, are administered orally using a dosing gun (Burke & Miller 2008). Once inside the digestive tract, the copper is slowly released and damages the internal structure of the parasites, reducing their survival (Burke & Miller, 2008). Studies in the United States and South Africa have shown that COWP can reduce parasite burdens by 60-90%, particularly against barber pole worm (Vatta et al., 2001). COWP is typically administered every 4-6 weeks during high-risk season (Burke & Miller, 2008). Compared with many commercial dewormers, COWP can be much more affordable. In some cases, treatment costs are approximately $4 per animal, while commercial deworming medications may cost $45 or more per treatment (Burke & Miller, 2008).
Challenges and Limitations of Low-Cost Deworming Approaches
Although low-cost methods are effective, they require additional labour and knowledge. This labour often falls on women in smallholder farming systems, which may increase workload (FAO, 2018). However, the economic benefits can outweigh these costs. For example, goats and sheep may be valued between $50 and $150 in many regions (Devendra, 1980). Preventing parasite-related losses can significantly improve household income (Perry & Randolph, 1999). Additionally, parasites can reduce milk production and growth rates, further affecting economic outcomes (Taylor et al., 2016). Some parasites, such as Fasciola hepatica, can also infect humans through contaminated food or water, posing public health risks (Mascoma et al., 2019). Currently, vaccines for parasites such as Haemonchus contortus are under development but are not widely available (FAO, 2018). Therefore, integrated management strategies remain the most practical solution.
Conclusion
Parasite infections are one of the most significant health challenges affecting goats and sheep worldwide. These infections reduce productivity, increase veterinary costs, and cause substantial economic losses for farmers, particularly in developing regions where livestock production is an important source of income (FAO, 2018). Effective parasite control therefore requires an integrated parasite management approach that combines strategic treatment methods, pasture management practices, and affordable control options.
Helpful links to get started
The FAMACHA System Demonstration
Shows how farmers identify anemia caused by Haemonchus contortus and selectively treat animals.
Dewormers and Dewormer Resistance
This video explains how parasites develop resistance to common deworming medications and why this has become a major challenge in livestock production. It also discusses strategies farmers can use to slow the development of drug-resistant parasites.
Genetic Resistance to Parasites in Goats
Explores how selective breeding can help produce goats that are naturally more resistant to parasite infections. It discusses how genetics may provide a long-term, sustainable solution for parasite control.
References
1. Adduci, I., Sajovitz, F., Hinney, B., Lichtmannsperger, K., Joachim, A., Wittek, T., & Yan, S. (2022). Haemonchosis in sheep and goats. Animals, 12, 2339. Link
2. Burke, J. M., & Miller, J. E. (2008). Use of copper oxide wire particles to control Haemonchus contortus in goats and sheep. Journal of Animal Science, 85, 2753-61. Link
3. Devendra, C. (1980). Potential of sheep and goats in less developed countries. Journal of Animal Science, 51, 461–473. Link
4. Food and Agriculture Organization. (2018). Parasite management guidelines for small ruminants. FAO, Rome. Link
5. COMBAR (2022). Targeted selective treatment of internal parasites in small ruminants. COMBAR Working Group, COST. Link
6. Kaplan, R. M. (2004). Drug resistance in nematodes of veterinary importance: A status report. Trends in Parasitology, 20, 477-81. Link
7. Merck Veterinary Manual. (2023). Gastrointestinal parasites in sheep and goats. Link
8. Northwest Livestock. (n.d). FAMACHA score: A guide to assessing anaemia in livestock. Link
9. O'Connor, L. J., Walkden-Brown, S. W., & Kahn, L. P. (2006). Ecology of the free-living stages of major trichostrongylid parasites of sheep. Veterinary Parasitology, 142, 1-15. Link
10. Taylor, M. A., Coop, R. L., & Wall, R. L. (2016). Veterinary parasitology (4th ed.). Wiley-Blackwell.
11. Van Wyk, J.A., & Bath, G.F. (2002). The FAMACHA system for managing haemonchosis in sheep and goats by clinically identifying individual animals for treatment. Veterinary Research, 33, 509-29. Link
12. Vatta, A. F., Letty, B. A., van der Linde, M. J., van Wijk, E. F., Hansen, J. W., & Krecek, R. C. (2001). Testing for clinical anaemia caused by Haemonchus contortus in goats farmed under resource-poor conditions in South Africa using an eye colour chart developed for sheep. Journal of Veterinary Research, 31, 1-14. Link
13. Waller, P. J. (2006). Sustainable nematode parasite control strategies for ruminant livestock by grazing management and biological control. Animal Feed Science and Technology, 126, 277-289. Link
14. Wikipedia contributors. (2024). Trichostrongylus. In Wikipedia. Link
15. WormBoss. (n.d.). Liver fluke in sheep and goats. Link
16. WormBoss. (n.d.) Lungworm in sheep and goats. Link