Most common sheep health conditions revealed
A recent analysis has identified the most common health conditions affecting sheep in Australia. The study provides critical insights into the prevalent diseases and disorders impacting sheep flocks, helping farmers and veterinarians improve management and treatment strategies. The findings underline the necessity of proactive health management to reduce losses and enhance animal welfare.
One of the most commonly reported conditions is internal parasitism, particularly from gastrointestinal worms. These parasites can cause weight loss, anaemia, diarrhoea, and even death if left untreated. Worm burdens can be particularly problematic in warm and wet conditions where larvae thrive in pasture. Farmers employ rotational grazing and strategic drenching to manage these parasites. However, resistance to some anthelmintics (worm treatments) is an ongoing challenge that requires careful monitoring.
Another significant health issue in sheep flocks is flystrike, a condition caused by blowfly infestation. This problem is particularly severe during warm and humid seasons, when flies lay eggs on the sheep’s fleece. Fly larvae then burrow into the flesh, causing pain, infection, and in severe cases, death. Preventative measures such as mulesing and shearing at appropriate times help reduce the risk. Flystrike prevention strategies also include chemical treatments and breeding programs to improve fleece characteristics that resist infestation.
Footrot remains a persistent problem in many sheep-producing regions. This bacterial infection affects the hooves, causing lameness, swelling, and tissue damage. Wet conditions often exacerbate footrot, as bacteria thrive in muddy or waterlogged environments. Farmers combat footrot through footbathing, culling of chronically affected animals, and vaccination. Strain typing can help determine the best control approach, as different strains of the bacteria respond to various treatments.
Lamb mortality due to environmental, nutritional, and infectious causes is another significant issue for sheep producers. Hypothermia and starvation are leading causes of death in newborn lambs, particularly in colder regions and during adverse weather conditions. Ensuring adequate nutrition for pregnant ewes supports the birth of stronger lambs, while providing shelter can improve survival rates. Management strategies, including better ewe nutrition and supervision during lambing, have been found to reduce mortality levels.
Johne’s disease, a chronic and incurable bacterial infection, affects sheep by causing gradual weight loss and diarrhoea. The disease spreads through contaminated pastures and remains difficult to diagnose in the early stages. Control measures include purchasing livestock from accredited-free flocks, maintaining strict biosecurity, and culling infected animals. There is no effective treatment, so prevention remains the best approach for managing this disease.
Ovine brucellosis is another serious condition, primarily affecting rams. This bacterial infection leads to infertility and reproductive failure, significantly affecting flock performance. The disease is transmitted through mating, and infected rams continue to spread the infection. Testing and culling of affected animals remain the primary control methods, while biosecurity measures help prevent new infections from entering flock populations.
Caseous lymphadenitis (CLA), also known as cheesy gland, is a bacterial infection that results in abscesses in the lymph nodes and internal organs. The condition can lead to economic losses by reducing wool and meat quality. CLA spreads through shearing cuts and other wounds. Vaccination helps reduce prevalence, and shearers are encouraged to maintain strict hygiene to limit transmission between sheep.
Nutritional deficiencies also contribute significantly to health issues in sheep. Low levels of essential minerals such as selenium, copper, and cobalt can result in poor growth, reproductive issues, and weakened immunity. Farmers conduct soil and pasture testing to identify deficiencies and provide supplementation where needed. Providing balanced nutrition is key to improving overall flock health and productivity.
Pregnancy toxaemia, or twin lamb disease, is a metabolic disorder that affects ewes carrying multiple lambs. It occurs due to inadequate energy intake during late pregnancy, leading to fat breakdown and toxic ketone production. Ewes affected by the condition display weakness, reduced appetite, and neurological signs. Treatment is only effective in the early stages, so prevention by ensuring proper nutritional management during pregnancy is vital.
White muscle disease, caused by selenium deficiency, affects lambs and results in muscle weakness and difficulty moving. Severely affected lambs may die if the condition is not addressed promptly. Providing selenium supplements to pregnant ewes helps prevent this disease, and some farmers inject young lambs with selenium if symptoms appear.
Management strategies to reduce these health conditions involve an integrated approach, combining vaccination, biosecurity measures, genetic selection, parasite control, and nutritional management. By closely monitoring flocks and implementing best-practice animal husbandry, farmers can reduce disease prevalence and improve sheep welfare. Continuing research and collaboration between producers and veterinary professionals will be essential in tackling emerging health challenges in the sheep industry.
References:
1. Farming Ahead – Most common sheep health conditions revealed: [https://www.farmingahead.com.au/sheep/news-analysis/4409714/most-common-sheep-health-conditions-revealed](https://www.farmingahead.com.au/sheep/news-analysis/4409714/most-common-sheep-health-conditions-revealed)
2. Agriculture Victoria – Sheep health and disease management: [https://agriculture.vic.gov.au/livestock-and-animals/sheep/health](https://agriculture.vic.gov.au/livestock-and-animals/sheep/health)
3. Department of Primary Industries and Regional Development, Western Australia – Common sheep diseases: [https://www.agric.wa.gov.au/livestock-biosecurity/common-sheep-diseases](https://www.agric.wa.gov.au/livestock-biosecurity/common-sheep-diseases)
4. Meat & Livestock Australia – Sheep health and welfare resources: [https://www.mla.com.au](https://www.mla.com.au)