羊肺炎持续困扰南澳大利亚州的生产者，但澳大利亚肉类与畜牧业协会（MLA）资助的研究，包括在可能的情况下尽量减少应激和管理环境因素。
该项目由Dynamic Ag公司的史蒂夫·科顿（Steve Cotton）博士和Joan Lloyd咨询公司的琼·劳埃德（Joan Lloyd）博士牵头，旨在更好地了解该疾病的流行率、潜在风险因素以及最大限度减少其影响的策略。
最新结果
史蒂夫表示，初步研究结果已于去年分享（可查阅MLA网站2025年冬季版《Feedback》），但进一步的采样和分析表明，该疾病仍然普遍存在，其流行率随季节或年份而变化。
“2024年，约22%的受检绵羊对羊肺炎病原体——绵羊肺炎支原体（Mycoplasma ovipneumoniae）呈阳性。最近的检测表明，流行率有所下降，2025年仅有14.8%的动物检测呈阳性，”史蒂夫说。
他指出，这一减少可能反映了部分地区季节条件的改善和营养应激的降低。
虽然不同牧场之间的发生率存在差异，但研究证实，该细菌在维多利亚州西部的绵羊种群中仍然广泛存在。
该研究在2024年至2025年间每年对750只母羊和阉羊进行了采样，发现同一羊群内也存在显著差异。在所研究的受感染羊群中，肺炎影响了7%至93%的绵羊。
重要的是，该研究未发现肺炎与品种、性别或地理区域之间存在明确的关联。
史蒂夫表示，早期数据表明复合品种绵羊的感染率较高，但这可能与品种本身无关，而是与管理因素有关，例如在更年轻时让母羊羔参与配种或采用更密集的饲喂系统。
该研究还支持了先前的发现，即感染可能在羊群内广泛传播，一些动物作为慢性携带者，在羔羊出生后不久即将细菌传播给它们。
应激仍然是主要的诱发因素
研究中最明显的规律之一是应激与肺炎发展之间的关联。
据史蒂夫称，羔羊断奶后被处理的次数似乎会增加感染的可能性，正常的牧场作业（如聚集、赶入畜栏、剪毛或驱虫）引起的应激，可能使细菌得以增殖。
环境条件也可能起作用。温度的突然变化、不利的季节条件或营养限制可能会减少采食量并增加动物的应激水平。
“这些细菌通常存在于绵羊种群中，但应激事件可使它们增殖并导致呼吸道疾病，”史蒂夫说。
多尘的环境也会刺激呼吸道，使动物更容易受到感染。
识别症状
肺炎的临床症状可能不明显。成年绵羊可能出现咳嗽、喘息、流泪或流涕、运动后呼吸困难或生产性能下降。
在羔羊中，咳嗽、流鼻涕、吸吮困难以及偶尔出现的膝关节肿胀等症状可能在1至2月龄时出现。
然而，在某些情况下，该疾病可能保持亚临床状态，仅表现为生长速度低于预期。
羊肺炎——需要注意的症状
肺炎的临床症状可能不明显——以下是一些需要注意的症状：
成年绵羊的症状：
咳嗽
喘息
流泪/流涕
运动后呼吸困难
生产性能下降
羔羊的症状：
咳嗽
流鼻涕
吸吮困难
膝关节肿胀
生长速度低于预期
减少对牧场的影响
虽然治疗方案仍然有限，但若干管理策略有助于降低疫情暴发的风险。
这些措施包括尽量减少不必要的赶入畜栏操作、保持充足的营养和饮水供应（包括尽可能确保水槽清洁），以及避免在育肥场或围栏区域过度拥挤。
监测羔羊的生长速度也有助于识别可能受影响的动物，生长较慢的羔羊可能需要更密切的检查或管理调整。
未来研究方向
当发现感染时，抗生素疗法是目前最常见的治疗方法，但研究人员仍在继续探索减少对抗生素依赖的长期策略。
目前的项目主要侧重于了解与羊肺炎相关的流行率和风险因素。随着更多数据的出现，预计这些研究结果将为未来的研究和生产者的管理策略提供参考。
降低羊群肺炎风险的八项措施
生产者可以通过采取减少应激和支持动物健康的实用管理措施，来降低羊肺炎的发生概率和影响。
1.尽量减少不必要的操作
在可能的情况下，限制羔羊断奶后被聚集或赶入畜栏的次数，并将管理任务（如称重、驱虫或分群）合并进行，以减少操作次数。
2.在关键管理环节管理应激
在断奶、剪毛、去臀毛和运输等操作过程中（运输前的准备工作至关重要）注意应激管理，特别是在季节条件不利的情况下。
3.保持良好的营养和饮水供应
确保绵羊能够获得充足的饲料和清洁的饮水，特别是在干旱、牧草生长不良或营养需求较高的时期。
4.避免过度拥挤
在围栏区、育肥场或畜栏内遵循推荐的放养密度，以减少应激和疾病传播。
5.监测羔羊生长速度
识别生长速度低于预期的羔羊，因为生长减缓可能是呼吸道疾病的早期迹象。
6.留意早期临床症状
留意咳嗽、喘息、流鼻涕、流泪或呼吸困难等症状，尤其是在1至2月龄的羔羊中。
7.尽早寻求兽医建议
如果怀疑发生肺炎，请及时联系兽医以确认诊断并讨论治疗方案。
8.审查羊群生物安全
考虑购入动物的健康状况，并对新入群牲畜进行监测，以降低将呼吸道病原体引入羊群的风险。
消息来源：MLA
Sheep pneumonia? Here’s how to protect flock health
Sheep pneumonia continues to challenge producers across southern Australia, but MLA-funded research including minimising stress and managing environmental factors where possible.
Led by Dr Steve Cotton of Dynamic Ag and Dr Joan Lloyd from Joan Lloyd Consulting, the project aims to better understand the disease’s prevalence, potential risk factors and strategies to minimise its impact.
Latest results
Steve said initial research findings were shared last year (check out the winter 2025 edition of Feedback at on the MLA website), but further sampling and analysis indicates the disease remains common, with prevalence varying depending on the season or year.
“In 2024, around 22% of tested sheep were positive for the sheep pneumonia pathogen Mycoplasma ovipneumoniae. More recent testing suggests prevalence has declined, with only 14.8% of animals testing positive in 2025,” Steve said.
He noted this reduction may reflect improved seasonal conditions and reduced nutritional stress in some regions.
While occurrences vary between properties, the research confirms the bacteria continues to be widely present in west Victorian sheep populations.
The study sampled 750 ewes and wethers each year between 2024–25 and found significant variations within individual flocks. Pneumonia impacted between 7–93% of sheep in the affected flocks involved in the study.
Importantly, the study found no clear links between pneumonia and breed, sex or geographic region.
Steve said early data suggested higher rates of infection in composite sheep, but this may be related to management factors such as joining ewe lambs at a younger age or more intensive feeding systems rather than breed itself.
The research also supports previous findings that infection can be widespread within a flock, with some animals acting as chronic carriers that spread the bacteria to lambs soon after birth.
Stress remains a key trigger
One of the strongest patterns emerging from the research is the link between stress and the development of pneumonia.
According to Steve, the number of times lambs are handled after weaning appears to increase the likelihood of infection, with the stress caused by normal on-farm activities such as mustering, yarding, shearing or drenching possibly allowing the bacteria to proliferate.
Environmental conditions can also play a role. Sudden changes in temperature, poor seasonal conditions or nutritional constraints may reduce feed intake and increase stress levels in animals.
“These bacteria are often present in sheep populations, but stress events can allow them to multiply and lead to respiratory disease,” Steve said.
Dusty conditions can also irritate the respiratory tract and make animals more susceptible to infection.
Recognising the signs
The clinical signs of pneumonia can be subtle. Adult sheep may show coughing, wheezing, runny eyes or nose, laboured breathing after exertion, or reduced performance.
In lambs, signs such as coughing, nasal discharge, difficulty suckling and, occasionally, swollen knee joints can appear from one to two months of age.
However, in some cases, the disease may remain subclinical and be attributed to slower-than-expected growth rates.
Sheep pneumonia – what to look out for
The clinical signs of pneumonia can be subtle –here are some of the signs to look out for:
Signs in adult sheep:
coughing
wheezing
runny eyes/nose
laboured breathing after exertion
reduced performance
Signs in lambs:
coughing
nasal discharge
difficulty suckling
swollen knee joints
slower-than-expected growth rates
Reducing the impact on farm
While treatment options remain limited, several management strategies can help reduce the risk of outbreaks.
These include minimising unnecessary yarding events, maintaining adequate nutrition and water supply (including ensuring clean trough water where possible), and avoiding overcrowding in feedlots or containment areas.
Monitoring lamb growth rates can also help identify animals that may be affected, and slower-growing lambs may require closer inspection or management adjustments.
Future research
Antibiotic therapy is currently the most common treatment when infection is detected, but researchers are continuing to investigate longer-term strategies to reduce reliance on antibiotics.
The current project is focused primarily on understanding the prevalence and risk factors associated with sheep pneumonia. As more data becomes available, the findings are expected to help inform future research and management strategies for producers.
Eight ways to reduce the risk of pneumonia in your flock
Producers can reduce the likelihood and impact of sheep pneumonia by focusing on practical management steps that minimise stress and support animal health.
1. Minimise unnecessary handling
Limit the number of times lambs are mustered or yarded after weaning where possible, and combine management tasks (e.g. weighing, drenching or drafting) to reduce handling events.
2. Manage stress around key husbandry events
Be mindful of stress during procedures such as weaning, shearing, crutching and transport (preparation for transport is critical), particularly during challenging seasonal conditions.
3. Maintain good nutrition and water supply
Ensure sheep have access to adequate feed and clean water, especially during periods of drought, poor pasture growth or high nutritional demand.
4. Avoid overcrowding
Follow recommended stocking densities in containment areas, feedlots or yards to reduce stress and disease transmission.
5. Monitor lamb growth rates
Identify lambs that are growing more slowly than expected, as reduced growth can be an early sign of respiratory disease.
6. Watch for early clinical signs
Look for coughing, wheezing, nasal discharge, runny eyes or laboured breathing, particularly in lambs from one to two months of age.
7. Seek veterinary advice early
If pneumonia is suspected, contact your veterinarian promptly to confirm diagnosis and discuss treatment options.
8. Review flock biosecurity
Consider the health status of purchased animals and monitor new stock to reduce the risk of introducing respiratory pathogens into the flock.
Source：MLA
