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National Sheep Health Monitoring Project

NSHMP Annual Report
2022-23
LAST UPDATED: 19 Dec 2023

Executive summary

The National Sheep Health Monitoring Project (NSHMP) operated throughout 2022-2023 in 10 abattoirs around the country. Meat inspectors inspected 9,822,174 sheep in 42,756 lines from 10,247 PICs for 19 animal health conditions. The 2022-2023 period saw the total number of inspected sheep increase by over 2 million animals compared to the previous financial year.

This report contains a basic analysis of the data from the project, including summaries of the monitored conditions, thus providing a snapshot of the health of a significant proportion of the Australian sheep flock. Of the conditions monitored in the 2022-2023 financial year (FY), bladder worm and pleurisy recorded the highest levels of incidence in inspected sheep throughout Australia at 2.9% and 1.8% of total inspected sheep, respectively (Table 1). 

Table 1: The percentage of inspected sheep that were affected by sixteen conditions inspected for in the 2020-23 FYs.

ConditionPercentage of animals affected
20/2121/2222/23
Arthritis0.60.80.8
Bruising0.40.40.4
Bladder worm2.32.52.9
Cheesy gland1.31.31
Dog bite0.030.050.04
Grass seed0.40.51.1
Hydatids0.01<0.01<0.01
Knotty gut0.090.10.3
Liver fluke0.50.60.9
Lungworm0.20.20.9
Nephritis32.21.3
Pneumonia0.30.50.5
Pleurisy1.21.71.8
Sarcocystosis0.10.20.2
Sheep measles1.31.61.4
Vaccination lesions1.31.41.2
*Abattoirs participating part-time in the project.

Objectives of the NSHMP

  • To monitor sheep for a range of significant animal health diseases and conditions which reduce productivity in the sheep value chain or can impact market access. 
  • To facilitate feedback to producers through state departments and MLA’s Livestock Data Link (soon to be replaced by myFeedback) about the diseases and conditions occurring in their flock.
  • To explore options for a comprehensive and cost-effective animal disease monitoring/surveillance system and post-mortem inspection service.
  • To provide accurate and timely animal health information as a driver for:
    • further improvements in Australia’s sheep health status 
    • maximising market access
    • improving profitability
    • informing future investment into research and development (R & D) 
    • enhancing productivity within the sheep value chain by improving the quality of product entering the chain and therefore reducing wastage

Location of participating abattoirs

A total of 10 abattoirs participated in data collection in 2022-2023 (some part-time) and provided national coverage of the significant sheep producing regions of Australia (Table 2). 

Table 2: Location of abattoirs participating in the NSHMP July 2022 – June 2023

StateAbattoir
New South WalesCowra, Dubbo, Gundagai, Tamworth
South AustraliaLobethal 
TasmaniaCressy
VictoriaArarat, Geelong*, Brooklyn*
Western AustraliaNarrikup
*Abattoirs participating part-time in the project.

Number of sheep inspected

The total numbers of sheep, lines and PICs inspected in 2022-23 have risen compared to the previous two years, especially with regards to the total number of sheep inspected at abattoirs. A new arrangement  came into effect in the SA plant during the 2022-23 year, which significantly increased the data made available to the NSHMP. An increasing Australian flock size over the last few years is also likely to have led to an increase in the number of animals processed this year.

Table 3: Total number of sheep, properties (PICs) and lines inspected in Australia over the past three FYs.

Inspected numbers2020-20212021-20222022-2023
Sheep8,894,1597,758,372  9,822,174
PICs8,7958,53610,255
Lines37,75834,32042,756

Source of sheep

Sheep were sourced from all Australian states. Of the 9.82 million sheep inspected during 2022-2023, 7.22 million were from direct lines and 2.59 million were from saleyards. For the state-specific data described in this report, only vendor consigned (direct lines) sheep are included. This is due to sheep from saleyards (indirect lines) possibly originating from states that differ from the one where the saleyard is located. Previous reports used both indirect and direct data for the below analysis, however a decision has been made to use only direct line data to improve the accuracy of the state figures. This may be changed in future reporting with the mandatory use of electronic identification (eID) in all states commencing in 2025, which will allow sheep to be more easily traced back to their property of origin (PIC).

Of the direct lines of sheep, 41% were from NSW, 21% from South Australia, 16% from Western Australia, 9% from Victoria and 7% from both Queensland and Tasmania. The total number of sheep inspected from each state (for most diseases and conditions) as well as those from direct lines only are provided in Table 4.

Table 4: Total number of sheep, properties (PICs) and lines inspected from each state over the 2022-2023 FY.

StateNo. of sheep inspected (direct lines only)No. of lambs inspected (direct lines only)No. of lines inspectedNo. of PICs inspected
NSW2,958,0952,220,85720,6353,253
QLD478,077259,7831,577395
SA1,485,192950,7898,1482,689
TAS478,142408,8493,895787
VIC635,544227,9394,0011,383
WA1,192,400515,3254,5001,748
Total7,227,4504,583,54242,75610,255

Meat inspection

Carcasses and viscera are examined grossly by certified meat inspectors. Laboratory confirmation of conditions is not utilised, except for ovine Johne’s disease. The presence or absence of pathology consistent with diseases and conditions is recorded by inspectors. 

Responsibility for product disposition for market access and food safety rests with the on-plant veterinarian and company management.  

NSHMP feedback and reporting

All producers have online access to feedback via MLA’s Livestock Data Link (LDL). Once producers log on, they have access to information about lines of sheep they have consigned to participating abattoirs, as well as information on prevention methods to help manage any conditions affecting their flock. MLA will soon launch a new system – myFeedback – to replace LDL. 

Regional quarterly reports providing a summary of the main sheep health conditions identified in a region and if the conditions have changed over time are provided to District Veterinarians and others on request.

Research and development activities utilising data

In 2022-23 the data from the NSHMP was utilised for: 

  • A pilot project was finished by Charles Sturt University investigating the increase in lamb kidneys affected by nephritis at an NSW abattoir. Using data from 2018-2021, testing of affected kidneys and a producer survey, the study aimed to understand the prevalence and risk factors associated with the condition, with the aim of developing recommendations for sheep producers and processors. The study found 4% of kidneys being condemned at the time of the study, with some mineralisation in over half of the condemned kidneys and the prevalence of predominant interstitial nephritis, suggestive of an underlying chronic infection. Recommendations were made by CSU including further investigation into the cause of these two findings and it is expected that this will occur in 2023-24.

Animal health information

This report contains a ‘snapshot’ of the health of the Australian sheep flock for the 2022-23 FY using data collected through the NSHMP. Summary data sets from previous years has been utilised for some conditions to provide a comparison.  

The data collected by the NSHMP is stored in the Endemic Disease Information System (EDIS), hosted by Animal Health Australia. 

  • The NSHMP collects information on 20 conditions:
    • Arthritis
    • Bladder worm
    • Caseous lymphadenitis (CLA, cheesy gland)
    • Dog bites
    • Grass seeds
    • Hydatids
    • Knotty gut
    • Liver fluke
    • Pleurisy
    • Pneumonia
    • Sarcocystosis
    • Sheep measles  
    • Vaccination lesions  
    • Lung worm
    • Rib fractures
    • Bruising 
    • Cirrhosis
    • Nephritis
    • Fever/septicaemia 
    • Ovine Johne’s disease (only on request by the producer)

  • Ovine Johne’s disease is not included in this report, as numbers of sheep inspected for it have been significantly lower than for the other conditions.
  • For the purpose of this analysis the information has been obtained from direct (vendor consigned) only. Ages of sheep are recorded in this report as all inspected animals are greater than two years (which includes some mixed age lines), and less than two years of age (mostly lamb). Analysis is at the animal level or by property identification code (PIC) level.

Top five conditions for each state during 22/23 (direct lines only)

Figure 1: The five most common conditions recorded in each state during 2022-23 based on percentage of inspected sheep (from direct lines) affected by them.

Arthritis

Arthritis in sheep is usually caused by a bacterial infection of the joints. It usually occurs in young sheep when bacteria localise in the joints after entering the body through the umbilical cord (navel ill) or any wound (e.g. at lamb marking). Arthritis causes lameness and a reduced growth rate. 

Carcases affected with arthritis undergo trimming of affected joints and may possibly be condemned.

The percentage of total animals reported to have arthritis is unchanged from the numbers reported in 2021-22 (Table 5). The number of animals <2 years affected by arthritis has increased slightly by 0.2% compared to last FY. The percentage of PICs with at least one affected sheep appears to have increased in Western Australia, New South Wales and Tasmania, but has otherwise decreased in all other states (Figure 2).

Victoria and South Australia recorded the highest percentages of affected animals at 1.37% and 1%, respectively (Figure 3). These two states also showed the highest incidence of arthritis in the previous FY.

Table 5: The number of sheep inspected and affected by arthritis during 2020-23.

 2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected51,106 = 0.6%64,041 = 0.8%77,900 = 0.8%
Total <2yr animals affected18,140 = 0.2%18,602 = 0.2%25,085 = 0.4%

Figure 2: The percentage of PICs inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 3: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 4: Percentage of sheep affected by arthritis in each LGA in 2022-23.

Bruising

Bruising of the muscle in sheep is caused by physical trauma, such as knocks and bumps from other sheep, during handling or during transportation. Significant levels of bruising can be an indication of poor handling techniques and impaired sheep welfare. Bruising can be avoided by practicing calm and safe handling techniques, having well designed sheep yards and not overcrowding sheep during transport.

Bruising is caused by damage to blood vessels in the muscle, discolouring the meat. Affected muscles are trimmed from the carcass, reducing yield and downgrading the carcass. 

The percentage of total sheep and PICs affected by bruising has been consistent over the last three years and remains at 0.4%. South Australia saw the largest percentage of inspected sheep affected, with 0.6% of sheep from this state having the condition (Figure 6). Bruising is generally seen in a relatively low number of animals and from a relatively small number of properties, with the highest state percentages of PICs with at least one case reported from Western Australia and New South Wales at 41% and 30%, respectively. Western Australia has seen a rise in the number of affected PICs compared to the previous FY, increasing by 7% (Figure 5).

Table 6: The number of sheep inspected and affected by bruising during 2020-23.

 2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected32,977 = 0.4%33,020 = 0.4%38,060 = 0.4%
Total <2yr animals affected13,737 = 0.2%12,777 = 0.2%17,824 = 0.3%

Figure 5: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 6: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).


Figure 7: Percentage of sheep affected by bruising in in each LGA in 2022-23.

Bladder worm

Bladder worms are infective cysts from the dog tapeworm Taenia hydatigena and are found in the liver and the abdominal cavities of sheep. Bladder worm has little or no effect on sheep health or production, but occasionally heavy infections can predispose sheep to the fatal bacterial infection, Black disease. 

Affected carcases usually have livers trimmed or condemned.

Bladder worm was the most commonly reported condition during 2022-23 and 2021-22. Compared to the previous year, the percentage of total sheep affected by bladder worm increased by 0.4%, and the percentage of affected lambs increased by 0.9% (Table 7). Bladder worm was most widely observed in Tasmania, with 71% of participating PICs reporting at least one case of the condition (Figure 8). New South Wales had the highest percentage of inspected sheep affected by bladder worm at 4.5%, closely followed by Tasmania at 4% (Figure 9).

Table 7: The number of sheep inspected and affected by bladder worm during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected206,257 = 2.3%194,063 = 2.5%281,370 = 2.9%
Total <2yr animals affected104,264 = 1.2%102,011 = 1.3%126,406 = 2.2%

Figure 8: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 9: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 10: Percentage of sheep affected by bladder worm in in each LGA in 2022-23.

Cheesy Gland

Cheesy gland (or caseous lymphadenitis – CLA) is a bacterial disease that results in the formation of lymph node abscesses throughout the body. Most commonly these abscesses are superficial, but they can also be found in the lungs, liver, spleen and kidneys. The abscesses are initially puss filled, which over time dries and becomes “cheesy” progressing to multi-layered capsules resembling “onion rings”. 

Cheesy gland causes a decrease in wool production, wool contamination, chronic infection which causes ill thrift, emaciation and can affect reproductive performance. 

Cheesy gland can result in a decrease in carcase weight and increased carcase trimming at the abattoir. 

The proportion of total inspected sheep affected by cheesy gland for the 2022-23 FY has decreased from 1.3% to 1.0% compared to the previous year. However, this remained unchanged for sheep younger than two years of age. 

The percentage of participating PICs with at least one reported case of cheesy gland was highest for Victoria and Western Australia at 57% and 56%, respectively (Figure 11). This has decreased in all states except for Tasmania, which increased by % of PICS for the 2022-23 FY. Victoria saw the largest proportion of inspected sheep with cheesy gland at 2.1%, followed by South Australia at 1.7% (Figure 12).

Table 8: The number of sheep inspected and affected by cheesy gland during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected111,838 = 1.3%100,670 = 1.3%100,630 = 1%
Total <2yr animals affected10,909 = 0.1%9,834 = 0.1%7,947 = 0.1%

Figure 11: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 12: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 13: Percentage of sheep affected by cheesy gland in in each LGA in 2022-23.

Grass seeds

Grass seeds embedded in the carcase due to spear, brome, barley, silver and Chilean needle grasses cause weaner ill thrift, infections and/or death, reduction in wool production and wool value. 

Grass seeds also cause trimming of the carcase and a decrease in meat and skin value. 

The total number of sheep carcasses affected by grass seeds increased in the 2022-23 financial year, growing by 0.6% compared to the previous year (Table 9). This number has steadily risen over the past three years, which may be associated with the higher-than average summer / autumn rainfall observed in sheep producing regions across Australia between 2020 and 2023. With the end of La Niña and progression into El Niño weather patterns, it’s possible that numbers of affected carcases may stagnate or reduce over the next reporting period. 

Figure 14 shows an increase in the total number of PICs affected by grass seeds in South Australia and Tasmania by 3% and 1%, respectively. However, the number of affected PICs in Western Australia has almost halved compared to the previous year. The percentage of impacted PICs is relatively low compared to other conditions, which suggests that grass seeds tend to be concentrated in certain areas, rather than being widespread over many PICs throughout the state. The state with the highest proportion of sheep affected by grass seeds was South Australia, with 2.7% of inspected sheep having the condition (Figure 15).  

Table 9: The number of sheep inspected and affected by grass seeds during 2020-23.

 2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected32,941 = 0.4%39,137 = 0.5%103,455 = 1.1%
Total <2yr animals affected26,144 = 0.3%29,650 = 0.4%79,743 = 1.4%

Figure 14: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 15: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 16: Percentage of sheep affected by grass seeds in each LGA in 2022/23.

Knotty gut

Knotty gut (also called pimply gut) is a condition of the intestines caused by the larval stage of the nodule worm (Oesphagostomum columbianum). These lesions can range from small gritty lesions 2-3mm in diameter, to pea sized cysts. Nodule worm eggs and larvae are particularly sensitive to cold weather and drying out, so tend to only exist in areas with predominately summer rainfall.

Affected intestines are unsuitable for sausage casings.

Although knotty gut incidence remains relatively low at 0.3% for 2022-23, the condition has increased in prevalence for this reporting period (up from 0.1% last year). Knotty gut was only seen on a small number of PICs, the most being found in Queensland with 7% of PICs having at least one case of the condition. Knotty gut was present on less than 1% of PICs for Western Australia, New South Wales and Tasmania. South Australia has the highest percentage of affected sheep with 1.65% of animals having the condition (Figure 18).

Table 10: The number of sheep inspected and affected by knotty gut during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected7,563 = 0.1%8,165 = 0.1%34,171 = 0.3%
Total <2yr animals affected2,962 = 0.03%3,200 = 0.04%15,621 = 0.3%

Figure 17: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 18: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 19: Percentage of sheep affected by pleurisy in each LGA in 2022-2023.

Liver fluke

Liver fluke are large, flatworm parasites that infect sheep and cattle in high rainfall areas and irrigated areas of eastern Australia. A permanent water source and specific snails are required for the liver fluke life cycle to occur. 

Affected livers are condemned at abattoirs and in some rare cases, whole carcases can be condemned.  

The percentage of total inspected sheep with liver fluke has slightly increased by 0.3% over the last financial year, and by 0.7% for sheep <2 years (Table 11). Liver fluke was not identified in Western Australia and only a very small number of cases were identified in Victoria, South Australia and Queensland. In previous years, Tasmania consistently had the highest percentage of affected PICs, however for the 2022-23 period this has decreased and been surpassed by New South Wales (Figure 20). 

New South Wales also had the largest percentage of total inspected sheep affected by liver fluke, with 2% of all sheep from direct lines in New South Wales having the condition (Figure 21).

Table 11: The number of sheep inspected and affected by liver fluke during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected47,717 = 0.5%44,130 = 0.6%89,784 = 0.9%
Total <2yr animals affected31,563 = 0.4%33,936 = 0.4%63,895 = 1.1%

Figure 20: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022-23).

Figure 21: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Lungworm

Figure 22: Percentage of sheep affected by liver fluke in each LGA in 2022-23.

Lungworm is a condition caused by the ingestion of the lungworm, mulleurius capillaris, that develop in the tissue of the lungs. This species of lungworm has a lifecycle that includes snails and is different from the one that inhabits the bronchi. Lungworm has no impact on sheep health or productivity. 

At the abattoir, lungs of infected sheep are condemned. 

There has been an increase in the occurrence of lungworm during the 2022-23 reporting period, with close to 1% of total animals inspected having the condition. There was also an increase in the proportion of lambs with lungworm, rising by 0.5% compared to the previous year (Table 12). South Australia reported the most PICs with the condition, with 22% of participating PICs having at least one case of lungworm (Figure 23). South Australia also had the largest total number of sheep affected by lungworm, with 4.3% of inspected sheep found to have the condition (Figure 24).

Table 12: The number of sheep inspected and affected by lungworm during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected16,270 = 0.2%14,431 = 0.2%86,002 = 0.9%
Total <2yr animals affected7,000 = 0.1%5,474 = 0.1%35,630 = 0.6%

Figure 23: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 24: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 25: Percentage of sheep affected by lungworm in each LGA in 2022-23.

Nephritis

Nephritis means inflammation of the kidneys. This can be caused by different factors such as infections (viral or bacterial), plant compounds or toxins. It is more commonly reported in lambs and is not normally associated with any clinical signs, although can reduce the growth and performance of lambs.

Affected kidneys are condemned, and in rare severe cases where kidney failure has occurred, whole carcass condemnation may occur. 

The occurrence of total inspected sheep with nephritis for this reporting period has reduced by almost 1% compared to the previous year, and has been steadily decreasing since 2020/21. The percentage of PICs with at least one animal affected by nephritis has decreased for every state, most notably in Tasmania where the percentage of PICs affected by nephritis dropped by 23% (Figure 26). 

Figure 27 shows that the states with the highest percentage of total sheep with nephritis were Queensland (3.05%) and New South Wales (2.72%). 

Table 13: The number of sheep inspected and affected by nephritis during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected267,107 = 3.0%173,038 = 2.2%125,860 = 1.3%
Total <2yr animals affected261,233 = 2.9%159,948 = 2.1 %106,779= 1.9%

Figure 26: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022/23).

Figure 27: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 28: Percentage of sheep affected by nephritis in each LGA in 202-23.

Pleurisy

In severe cases of pneumonia, infection can extend to the outer layer of the lung, the pleura, causing a disease called pleurisy. This can cause adhesion of the lungs to the chest wall as the infection spreads in the sheep.

Affected carcasses will require additional trimming compared to pneumonia which can include damage to the valuable rib rack, significantly de-valuing the carcass.

Pleurisy was the second most reported condition after bladder worm, with 1.8% of total inspected sheep having the condition. This number has been steadily increasing over the past three years and has now doubled in sheep <2 years compared to last year. Pleurisy occurs on a relatively high number of PICs, with both Victoria and Western Australia reported to have at least one case of pleurisy on approximately 80% over the past two years (Figure 29). 

Victoria has the highest percentage of affected animals at 3.3%, followed by Tasmania and South Australia with 2.7% and 2.4%, respectively (Figure 30). 

Table 14: The number of sheep inspected and affected by pleurisy during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected109,921 = 1.2%129,824 = 1.7%181,697 = 1.8%
Total <2yr animals affected33,467 = 0.4%40,068 = 0.5%59,054 = 1.0%

Figure 29: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022-23).

Figure 30: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 31: Percentage of sheep affected by pleurisy in each LGA in 2022-2023.

Pneumonia

Pneumonia in sheep is inflammation of the lungs. Pneumonia is initially caused by an infection with a bacterium (especially Mycoplasma ovipneumoniae) or virus, or sometimes lungworm, with secondary bacterial invasion of the damaged lungs. The disease can be limited to isolated cases or can result in outbreaks of disease typically in weaners over summer and is often called “summer pneumonia”. Production losses can be seen on farm with affected lambs being on average 3 kg lighter.

Lungs will be condemned, and any surrounding affected tissue would be trimmed (see pleurisy).

The percentage of total inspected sheep with pneumonia remains unchanged from the previous year at 0.5% (Table 15). However, the percentage of lambs affected by pneumonia has increased slightly from 0.4% in 2021-22 to 0.7% in 2022-23. The condition is most widespread in Western Australia, with 21% of PICs reporting at least one case of the condition in 2022-23, which is also unchanged from the previous year (Figure 32). However, only a relatively small proportion of inspected sheep in Western Australia had pleurisy (0.18%), which indicates that the affected animals are occurring in small quantities across a large number of PICs.

The state with the highest proportion of sheep affected by pneumonia was South Australia, with 1.33% of inspected sheep in this state having the condition (Figure 33). This is followed by New South Wales and Victoria with 0.47% and 0.44% of animals inspected with pneumonia, respectively.

Table 15: The number of sheep inspected and affected by pneumonia during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected26,646 = 0.3%37,814 = 0.5%51,585 = 0.5%
Total <2yr animals affected24,023 = 0.3%32,874 = 0.4%41,563 = 0.7%

Figure 32: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022-23).

Figure 33: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 34: Percentage of sheep affected by pneumonia in each LGA in 2022-2023.

Sarcocystosis

Sarcocystosis is a disease caused by Sarcocystis, a single cell parasite with a sheep-cat life cycle. Cats become infected when they eat infected sheep meat, often through scavenging carcasses. The parasite develops in the intestines of the cat, and they produce large quantities of microscopic spores in their faeces. The life cycle continues when sheep ingest these spores on pasture or feed, eventually localising and developing into cysts in the muscle. Sarcocystosis has no impact on sheep health or productivity. 

At the abattoirs, infected carcases will undergo trimming while carcases with more than five cysts will be condemned.  

The percentage of total inspected sheep with Sarcocystis has remained unchanged at 0.2%, however, the percentage of affected lambs has increased slightly by 0.08% (Table 16). Tasmania has the highest percentage of affected PICs, with 15% having at least one animal with Sarcocystis. Western Australia saw a significant decrease in the percentage of affected PICs, dropping by 9% compared to the previous year (Figure 35). 

Tasmania also has the highest percentage of affected sheep, with 1.5% of inspected sheep in this state having Sarcocystis.  This was followed by South Australia, with approximately 1% of inspected sheep being affected (Figure 36).

Table 16: The number of sheep inspected and affected by sarcocystosis during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected12,479 = 0.1%15,245 =0.2%23,837 = 0.2%
Total <2yr animals affected1,068 = 0.01%1,432 = 0.02%5,739 = 0.1%

Figure 35: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022-23).

Figure 36: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 37: Percentage of sheep affected by sarcocystosis in each LGA in 2022-23.

Sheep measles

Sheep measles (Cysticercus ovis) are infective cysts from the dog tapeworm Taenia ovis, found in the muscles of sheep and goats. 

At the abattoirs, infected carcases will undergo trimming while carcases with more than five cysts will be condemned.

The total proportion of inspected sheep with sheep measles in 2022-23 slightly decreased by 0.2% compared to the previous year. However, the percentage of affected lambs increased by 0.3% (Table 17). Sheep measles is a fairly widespread condition and is seen on a relatively large number of properties. Tasmania has the highest proportion of affected PICs, with 77% of properties having at least one case of sheep measles. This was followed by Western Australia and Victoria with 67% and 65% of affected PICs, respectively (Figure 38). 

Tasmania also has the highest percentage of affected animals, with 2.6% of inspected animals in this state having sheep measles.  This was followed by Victoria and South Australia, which both reported 1.9% of inspected sheep affected with the condition (Figure 39). 

Table 17: The number of sheep inspected and affected by sheep measles during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected115,857 = 1.3%120,455 = 1.6%138,619 = 1.4%
Total <2yr animals affected50,953 = 0.6%50,109 = 0.6%54,347 = 0.9%

Figure 38: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022-23).

Figure 39: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 40: Percentage of sheep affected by sheep measles in each LGA in 2022-23.

Vaccination lesions

Vaccination lesions can be caused by improper technique, poor hygiene or using a contaminated vaccine. The accidental introduction of bacteria or dirt with the vaccine results in infection which can lead to abscess formation. 

At the abattoir, vaccination lesions are trimmed from the carcase. 

The total number of sheep with vaccination lesions has decreased slightly from 1.4% to 1.2% compared to the previous year (Table 18). The proportion of lambs affected by vaccination lesions has increased from 0.8% to 1.4% and has been on an increasing trend since 2020/21. The highest percentage of affected was seen in Victoria, with at least one affected animal occurring on 37% of PICs (Figure 41). 

South Australia saw the highest percentage of total effected animals, with 3.7% of inspected sheep in this state having vaccination lesions. This was followed by Victoria with 2.5% (Figure 42). 

Table 18: The number of sheep inspected and affected by vaccination lesions during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected113,805 = 1.3%111,319 = 1.4%120,620 = 1.2%
Total <2yr animals affected58,059 = 0.7%59,109 = 0.8%82,537 = 1.4%

Figure 41: The percentage of PIC’s inspected in each state that had at least one affected animal in 2020-23 (direct lines only for 2022-23).

Figure 42: The percentage of animals inspected in each state that were affected in 2022-23 (direct lines only).

Figure 43: Percentage of sheep affected by vaccination lesions in each LGA in 2022-23.

Conditions with prevelance ≤ 0.1%

Cirrhosis

Numbers of animals affected has increased in 2022-23 but remain below 0.1%. Cirrhosis is the chronic damage of liver tissue as a result of other diseases and conditions such as liver fluke. Sheep affected by cirrhosis may also have lost condition or show other signs of illness.

Affected livers are discarded at the abattoir.

Table 19: The number of sheep inspected and affected by cirrhosis during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected4,062 = 0.05%2,574 = 0.03%7,370 = 0.08%
Total <2yr animals affected1,355 = 0.02%743 = 0.01%1,987 = 0.03%

Dog bites

Dog bites occur as a result of un-muzzled or incorrectly muzzled dogs with access to sheep, either in the paddock, yards or during transport. Some may have occurred from previous wild dog attacks on farm. Abattoirs require dogs to be muzzled at all times. Dog bites usually occur in the hind quarters, but also can occur on the face or along the back. The Australian Animal Welfare Standards and Guidelines for Sheep states: ‘A person in charge of a dog that habitually bites sheep must ensure the dog is muzzled while working sheep’.

Carcases of sheep with dog bites are usually trimmed to the nearest joint which may be the entire hind leg, resulting in a significant reduction in dressed weight. Occasionally whole carcases are condemned when wounds are infected, and the animal is showing evidence of septicaemia (blood poisoning).

Table 20: The number of sheep inspected and affected by dog bites during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected3,045 = 0.03%3,976 = 0.05%4,053 = 0.04%
Total <2yr animals affected1,833 = 0.02%2,582 = 0.03%2,555 = 0.04%

Fever / Septicaemia

Fever or septicaemia are likely to be signs of other illness or infection somewhere in the body.

As septicaemia is an infection of the body, whole carcasses will be condemned.

The percentage of sheep affected with fever and / or septicaemia has increased from 0.01% to 0.04% in 2022-23. Although still at relatively low levels, this increase is of note as numbers remained unchanged for the two years prior. 

Table 21: The number of sheep inspected and affected by fever / septicaemia during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected1,106 = 0.01%1,159 = 0.01%3,856 = 0.04%
Total <2yr animals affected504 = < 0.01%698 = < 0.01%1,695 = 0.03%

Hydatids

Hydatids are the large cysts from the dog hydatid tapeworm (Echinococcus granulosus) which develop mainly in the liver and/or lungs of infected sheep. 

If infected, sheep organs will be condemned at the abattoir. 

Table 22: The number of sheep inspected and affected by hydatids during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected625 = < 0.01%360 = < 0.01%1,402 = 0.01%
Total <2yr animals affected245 = < 0.01%101 = <0.01%457 = 0.01%

Rib fractures

Rib fractures can be caused by a number of factors and are likely linked to reduced bone density caused by nutritional deficiencies. Most cases occur in SA. Rib fractures can also be an indication of wider animal welfare problems. Safe handling practices and good nutrition will help to prevent rib fractures.

Affected ribs and surrounding tissue is discarded, potentially impacting some of the high value meat cuts, reducing the value of the carcass. 

Table 23: The number of sheep inspected and affected by rib fractures during 2020-23.

2020-212021-222022-23
Total animals inspected8,894,1597,758,3729,822,174
Total animals affected5,570 = 0.06%7,052 = 0.1%13,333 = 0.1%
Total <2yr animals affected4,358 = 0.05%5,481 = 0.1%8,821 = 0.2%

State contacts

StateNameOrganisationNumber
New South WalesDr Dione HowardNSW Department of Primary Industries0428 115 134
South AustraliaDr Jemma HassamDepartment of Primary Industries and Regions, SA08 8429 4348
TasmaniaDr Tahlia RoyceDepartment of Natural Resources and Environment Tasmania0497 354 091
VictoriaDr Alison LeeDepartment of Economic Development, Jobs, Transport and Resources03 5561 9927
Western AustraliaDr Anna EricksonDepartment of Primary Industries and Regional Development0437 801 416
QueenslandDr Lawrence GaveyDepartment of Agriculture and Fisheries0499 860 249

Industry contacts

IndustryEmail
Sheep Producers Australiaadmin@sheepproducers.com.au
WoolProducers Australiaadmin@woolproducers.com.au

AHA acknowledges the participating plants and MINTRAC for helping coordinate the project as well as provide training and validation work at all participating abattoirs.