Mulesing

Ratification date: 16/07/26

 

Purpose 

To provide a platform for AVA to advocate for the phase-out of mulesing, and to emphasize the role of veterinarians in assisting producers to transition. 

Policy 

  1. It is important that mulesing is phased out as soon as a sustainable transition to flystrike-resistant sheep can be achieved.
  2. A sudden ban is not advocated, due to the devastating effects and suffering caused by flystrike; it is essential that a phase-out period is established during which accelerated breeding for flystrike resistant sheep is prioritised. 
  3. Industry, veterinarians and government extension officers should all work together to achieve this outcome in the shortest possible time frame.
  4. During the transition period, non-surgical and non-painful procedures to reduce the risk of breech strike should be used in preference to mulesing wherever practical and effective.
  5. In cases where mulesing is performed during the transition period, the welfare impacts must be mitigated through use of appropriate technique and mandatory multi-modal analgesia.
  6. The Animal Welfare Task Group should expedite the review of the Australian Animal Welfare Standards and Guidelines for Sheep, particularly the chapters on mulesing and other surgical husbandry procedures. 

Definitions 

For the purposes of this policy, ‘mulesing’ includes any painful breech modification procedure, including surgical and non-surgical methods (clips, freezing and intra-dermal injections to cause skin necrosis and sloughing). 

Multi-modal analgesia refers to the use of multiple methods or medications to manage pain more effectively, such as the combination of local anaesthesia and systemic non-steroidal analgesics (NSAIDs).  

Background 

Flystrike (cutaneous myiasis) is a severe disease of sheep which causes considerable suffering and is usually fatal if left untreated (Hemsworth et al, 2009). Surgical mulesing was developed to reduce the risk of flystrike on the breech area of highly wrinkled Merino sheep, as they are especially prone to flystrike.  It involves the excision of sufficient perineal, caudal thigh and tail skin to result in a healed surface with reduced skin wrinkle; this smoother skin is less prone to soiling and a less attractive environment for flies to deposit their eggs. 

The mulesing procedure causes acute pain, distress and altered behaviour for up to 3 weeks after the operation (Hemsworth et al, 2009). Controlled studies report strong pain-related behaviours (reduced feeding and walking; increased head-down postures; abnormal standing/lying) and heightened wound sensitivity relative to untreated lambs. Physiological indicators and behavioural ethograms confirm marked acute pain behaviours and longer  duration of pain with surgical mulesing compared with non-surgical alternatives or controls (Hemsworth et al, 2009; Edwards et al, 2011).  

Pain relief options include topical local anaesthetic (containing lignocaine, bupivacaine, adrenaline and cetrimide) and NSAIDs (e.g., meloxicam); these are most effective when administered together (multi-modal analgesia) but will only reduce, not eliminate, pain-related behaviours (Small et al, 2018). From a welfare perspective, removing the need for the procedure is preferable to mitigating its consequences (Inglis et al, 2019; Small et al, 2018). 

Industry have previously attempted to phase out the practice of mulesing, but in 2026, only approximately 25% of the wool sold at auction is derived from unmulesed sheep.  Approximately 45% of wool auctioned comes from sheep that have been mulesed with pain relief; approximately 7% mulesed without pain relief; and about 20% of the wool is sold without mulesing status declared. Some Australian wool is sold through other channels, so it is not captured in the above figures.  

An MLA study in 2023 indicated that 71% of producers who mulesed were unlikely to cease mulesing (MLA, 2024), presumably because their flocks are still vulnerable to fly strike. This indicates a need for stronger industry and government support for producers to transition their flocks to be genetically less susceptible to fly strike. Of those who have ceased mulesing, the main reasons recorded were breeding for less body wrinkle, animal ethics, and industry and consumer pressure (MLA, 2024). 

There has been significant research investment by industry into alternative breech-modifying procedures. Trials of non-surgical breech modification methods, such as plastic breech clips and injections of intradermal sclerosing agents, have shown lower acute pain responses when compared with surgical mulesing (Edwards et al, 2011; Hemsworth et al, 2009), however these alternatives still involve pain and risk to the animal, so are not the preferred solution from a welfare perspective.  There has been variability in success rates and field durability, so these methods have not achieved widespread adoption. 

It is acknowledged that a sudden ban on mulesing is not desirable and would have negative consequences for animal welfare, due to the significant adverse effects of fly strike. A phase-out period is necessary to achieve permanent genetic change to low-wrinkle-flocks. A combination of integrated management in the short-to-medium term, with planned multi-trait selection for flystrike resistance can allow a phase out in Merino flocks in a commercially realistic timeline, while maintaining or improving productivity (Edwards et al, 2011; Brien et al, 2021).  

 

Current legislative situation  

The Australian Animal Welfare Standards and Guidelines – Sheep require that sheep must not be mulesed if they are less than 24 hours old or older than 12 months. Pain relief is mandated for sheep over 6 months of age. (Note that the AVA policy Use of analgesia for painful husbandry procedures says that analgesia must always be used, irrespective of the age of the animal).  

In Victoria, Tasmania and NSW it is now compulsory to use some form of pain relief for mulesing at any age. The AVA advocates that a requirement for multimodal pain relief should be mandated in all jurisdictions, and that the Sheep Standards should be reviewed as soon as possible to reflect this community expectation.  

 

The genetic pathway to phase out mulesing in Merinos 

Large, multi-flock studies demonstrate that the predisposing breech traits — breech wrinkle, breech cover (wool coverage), and dags (faecal soiling) — are heritable, genetically correlated with breech strike, and can be improved without unacceptable penalties to key wool and reproduction traits when included in a balanced index. Key findings: 

  • Heritability & indicator traits. Breech strike itself can have low to moderate heritability depending on environment, but its indicator traits (wrinkle, breech cover, dag score; sometimes urine stain, neck wrinkle) are consistently heritable and predictive across environments. Selecting against these traits reduces strike risk. (Greeff et al, 2014) 
  • Lifetime risk & correlations. Some work shows moderate genetic correlations in strike risk across ages, supporting culling of animals struck when young. (Greeff et al, 2021)  
  • Rate of genetic gain. Modelling and open-access trials indicate substantial reductions in breech flystrike incidence are achievable and many farmers and researchers have phased out mulesing within 10 years (see list in Appendix A). Gains are larger where strike heritability is moderate (e.g., summer-rainfall zones) but are still possible in lower-heritability environments (Brien et al, 2021; Brien et al, 2019). There is potential for a more rapid genetic gain through the use of advanced breeding techniques such as artificial insemination and/or embryo transfer. Rate of genetic gain can be further improved by selecting sheep with only low wrinkle for enrolment in breeding programs.  
  • There is no single “major gene” for flystrike. Flystrike susceptibility is polygenic; genomic selection can assist, but progress relies on whole flock/multi-flock recordings and index selection rather than a marker for a single locus. (AWI, 2019) 

Short-to-medium term management strategies during genetic transition of a flock  

The peer-reviewed consensus is that breeding sheep that do not require mulesing is the most sustainable and welfare-friendly option, supplemented by integrated management while genetic change accumulates (Fisher 2011; Brien et al, 2021). There are a range of methods with the potential to manage breech strike risk while a flock transitions genetically: 

  • Diligent breech hygiene and husbandry to reduce scouring and dag score: More frequent crutching, strategic shearing, targeted chemical protection during high-risk periods, and good management of nutrition and intestinal parasites will reduce strike pressure. It should be noted that repeated crutching can also be a welfare concern and can cause significant trauma to the breech area in highly wrinkled Merinos, so this needs to be conducted judiciously using appropriate technique. Attention to tail docking length is also important, as there is evidence that the practice of short tail docking is widespread, which increases flystrike risk (Woodruff et al, 2024). Shearing more frequently than once per year can also assist with reducing risk, see: https://flyboss.com.au/management/shearing-and-crutching/  Best outcomes are achieved by consulting a sheep veterinarian to get a program customised for the individual plan. 
  • Multimodal analgesia (if mulesing is still used during the transition): Randomised controlled studies show topical anaesthetic (containing lignocaine, bupivacaine, adrenaline and cetrimide) and buccal meloxicam can each help to reduce the pain response; however, when used in combination they provide the most consistent reduction in pain-related behaviours and wound sensitivity. Both an NSAID and a local anaesthetic should be used whenever any painful breech/tail procedure is unavoidable (Lomax et al, 2008; Small et al, 2018; Inglis et al, 2019). 

 

Recommendations  

  • Studs which have plainer breeches and/or have bred out wrinkles should be showcased by industry to encourage others to make this change.   
  • Veterinarians and industry experts should be consulted by farmers undertaking transition to a non-mulesed flock.  AWI’s Fly Extension Program includes group and individual sessions with accredited advisors (see Resources below) There should be government funding to support these types of extension programs. 
  • Industry should commit to a deadline, or the government should establish one (to prevent the timeline being pushed out indefinitely). The Animal Welfare Task Group should establish biennial benchmarks to monitor the industry’s progress toward the phase-out. 
  • All states and territories must mandate multimodal pain relief in their legislation for mulesing during phase-out period 
  • Training of contractors – appropriate surgical and non-surgical technique and appropriately administered multimodal pain relief 
  • Industry incentives should be provided to expedite the transition to flystrike resistant flocks. 

 

Guidelines 

A step-by-step breeding plan and realistic phase out pathway 

  1. Define the breeding objective to remove the need for mulesing by prioritising breech strike resistance, balanced with fleece weight, fibre diameter and reproduction. Use a published index [e.g., Australian Sheep Breeding Values (ASBV)-style indexes incorporating flystrike incidence or validated indicator traits). (Brien et al, 2021) 
  2. Commit to a time-bound phase-out flock-wide. Modelled and empirical work shows it is possible to materially lower strike risk while maintaining or improving wool and reproductive performance when using balanced indexes. (Brien et al, 2021; Brien et al, 2019) 
  3. Only buy and breed from rams with high Breech Strike Resistance ASBVs. During the transition, replace routine mulesing with risk-based management if possible. 
  4. Escalate crutching frequency around high-risk weather, use targeted chemical protection, and manage nutrition and intestinal parasites to reduce dags. 
  5. If any surgical or non-surgical mulesing procedures remain during the interim, use both topical local anaesthetic and an NSAID as standard of care. (MLA 2020; Small et al, 2018) 

 

Resources

 To assist producers to transition to non-mulesed flocks:

 

Please see Appendix A for further resources including information on individual farms which have successfully transitioned. 

To assist producers with mulesing technique during the transition phase: 

It is essential that the mulesing procedure is performed by competent operators, and that the minimum amount of skin required to achieve the desired outcome is excised. There are anecdotal reports of operators excising excessive skin beyond the immediate breech area.  It is essential that operators are trained and adhere to best practice technique wherever mulesing is used during the transition period. Industry guidelines are available, such as the below: 

References 

AWI (2019). Genotyping of breech flystrike resource – update. Australian Wool Innovation: https://docslib.org/doc/244367/genotyping-of-breech-flystrike-resource-update 

Brien FD, Walkom SF, Swan AA and Brown DJ (2021). Substantial genetic gains in reducing breech flystrike and in improving productivity traits are achievable in Merino sheep by using index selection. Animal Production Science, 2021, 61, 345–362: https://doi.org/10.1071/AN20248 

Brien, FD, Walkom SF, Swan AA and Brown DJ (2019). Breeding for reduced breech flystrike as part of multi-trait selection. Conference Paper:  https://www.researchgate.net/publication/337019338 

CSIRO, AWI, Department of Agriculture and Food WA (2016). Breech strike genetics, Issue 7, November: https://www.wool.com/globalassets/wool/sheep/welfare/breech-flystrike/breeding-for-breech-strike-resistance/link-collection-2/breech-strike-genetics-issue-7.pdf 

Edwards LE, Arnold NA, Butler KL, Hemsworth PH (2011). Acute effects of mulesing and alternative procedures to mulesing on lamb behaviour. Applied Animal Behaviour Science, Volume 133, Issues 3–4, Pages 169-174, ISSN 0168-1591: https://doi.org/10.1016/j.applanim.2011.05.014 

Fisher, A (2011). Addressing pain caused by mulesing in sheep. Applied Animal Behaviour Science, Volume 135, Issue 3. Pages 232-240 https://doi.org/10.1016/j.applanim.2011.10.019 

Greeff JC, Karlsson LJE, Schlink AC (2014) Identifying indicator traits for breech strike in Merino sheep in a Mediterranean environment. Animal Production Science 54, 125-140: https://doi.org/10.1071/AN12233 

Greeff JC, Schlink AC, Karlsson LJE (2021) Genetic parameters of breech strike, neck wrinkles, dags and breech cover over the lifetime of crutched Merino ewes in a Mediterranean environment. Animal Production Science 61, 1893-1904: https://doi.org/10.1071/AN20415 

Hemsworth PH, Barnett JL, Karlen GM, Fisher AD, Butler KL, Arnold NA (2009). Effects of mulesing and alternative procedures to mulesing on the behaviour and physiology of lambs. Applied Animal Behaviour Science, Volume 117, Issues 1–2, Pages 20-27, ISSN 0168-1591: https://doi.org/10.1016/j.applanim.2008.12.007 

Inglis L, Hancock S, Laurence M, Thompson A (2019). Behavioural measures reflect pain-mitigating effects of meloxicam in combination with Tri-Solfen® in mulesed Merino lambs. animal. 13(11):2586-2593. DOI: https://doi.org/10.1017/S1751731119000491 

Lomax, S, Sheil, M and Windsor, PA (2008), Impact of topical anaesthesia on pain alleviation and wound healing in lambs after mulesing. Australian Veterinary Journal, 86: 159-168. https://doi.org/10.1111/j.1751-0813.2008.00285.x 

MLA (2020). Fact sheet – Pain mitigation in sheep. https://elearning.mla.com.au/wp-content/uploads/2020/11/20MLA-Pain-mitigation-factsheet_Sheep_v4.pdf 

MLA (2024). National Sheep Producer Survey of Animal Husbandry Practices. Final Report: https://www.mla.com.au/globalassets/mla-corporate/news-and-events/documents/flyers/e.ssf.0001-national-sheep-producer-survey-report-final.pdf 

NWD (2025): https://www.awex.com.au/AWEX-National-Wool-Declaration-Auction-Data.pdf  

RSPCA (2024). Research-report-Prevention-and-control-of-flystrike-in-sheep-2024-update.pdf 

Small A, Marini D, Dyall T, Paull D, Lee C (2018). A randomised field study evaluating the effectiveness of buccal meloxicam and topical local anaesthetic formulations administered singly or in combination at improving welfare of female Merino lambs undergoing surgical mulesing and hot knife tail docking. Research in Veterinary Science, Volume 118, Pages 305-311, ISSN 0034-5288: https://doi.org/10.1016/j.rvsc.2018.03.006 

Woodruff ME, Munoz CA, Coleman GJ, Doyle RE, Barber SR (2024) Sheep producers report docking tails shorter than recommended, knowledge–practice gap, and inconsistent length descriptions: an Australian survey. Animal Production Science 64, AN24142: https://doi.org/10.1071/AN24142

 

Appendix A – Additional resources  

Breeding for Flystrike resistance – https://www.sheepmetrix.com.au/blog/join-the-merino-flystrike-reference-flock-on-the-path-to-genomic-prediction 

MLA on-farm transitioning study over 5 years – https://www.mla.com.au/extension-training-and-tools/search-pds/pds-data/supporting-sheep-producers-transition-to-non-mulesed-sheep/

 

Success stories – farms that have transitioned to non-mulesed: 

Farmers share they can transition in as little as 5 years in some cases to non-mulesed sheep via genetics (note these are farmer-reported timeframes):  https://www.sheepcentral.com/is-the-srs-merino-a-genetic-answer-to-fewer-shearers/ – –  

UWA – transitioned their flock to non-mulesed: https://www.uwa.edu.au/news/article/2021/march/uwa-farm-ridgefield-demonstrates-shift-to-non-mulesed-sheep 

https://www.parkdalesrs.net.au/ – run over 20,000 sheep 

https://mumblebone.com.au/about/ – run over 20,000 sheep 

https://www.rabobank.com.au/insights/2023/the-peters-family-championing-the-modern-merino – 8 year to phase out their commercial farm 

https://www.burbidgefarms.com/about  – 30,000 sheep 

https://woolsolutions.com.au/ashby-farm/ – 20,000 sheep 

https://woolsolutions.com.au/benham-farm/ – 20,000 sheep 

https://woolsolutions.com.au/beaufront-farm/ – 20,000 sheep 

https://woolsolutions.com.au/allanvale/ – 15,000 sheep 

https://woolsolutions.com.au/kenilworth/ – 14,000 sheep 

https://www.droverag.com.au/jobview/farm-manager-fine-wool-merino-breeding-crookwell-nsw/ce6c671b-ccf7-4c3f-b5f6-3dc520fb54ae/expired/ – Markdale Station 10,000 sheep 

https://woolsolutions.com.au/mount-morriston-farm/ – 10,000 sheep 

https://www.aloeburnpollmerinos.com/about – 6500 sheep