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What is mulesing and what are the alternatives?

Article ID: 113
Last updated: 20 Nov, 2015
Revision: 4
Views: 51074

Mulesing was developed in 1927 and for over 80 years it has been a routine husbandry procedure for the majority of merino sheep in Australia. Merinos have woolly wrinkles and folds in their skin, which, around the tail and breech area, become moist with urine and contaminated with faeces. Particularly in hot and humid conditions, blowflies are attracted to this moist area where they lay eggs. Eventually the eggs hatch and maggots eat away at the flesh of the live animal — this is flystrike.

Mulesing involves cutting flaps of skin from around a lamb’s breech and tail to create an area of bare, stretched skin. Because the scarred skin has no folds or wrinkles to hold moisture and faeces, it is less attractive to blowflies. This makes mulesed merinos less susceptible to flystrike.

Research shows the pain of mulesing is similar to that of castration, but it lasts longer (up to 48 hours). The RSPCA is opposed to practices that cause suffering or distress to animals and does not accept that mulesing should be performed as a routine husbandry procedure. It should be the last option farmers choose to control flystrike and only when the risk of flystrike is very high.

The RSPCA view on mulesing is that:

  • it should not be done if other humane procedures can protect sheep from flystrike
  • it must only be used as a management procedure in areas where it is known it will reduce the incidence of flystrike
  • it must only be performed by a competent person on a well-restrained lamb that is less than 10 weeks of age and using appropriate pain relief
  • older animals require anaesthesia during mulesing and aftercare to help healing
  • lambs should not be mulesed if they are sold at an early age for meat.  

Alternatives to mulesing

Public pressure to improve sheep welfare has led to the wool industry researching alternatives to mulesing. The RSPCA supports work on safe and humane ways to reduce flystrike and encourages industry to give this priority. Various studies are underway, including:


Breeding offers the only long-term solution. The genetic traits that can be bred out of sheep to reduce flystrike have been found. They are: wrinkles; a bare area around the breech and tail; resistance to worms; susceptibility to diarrhoea; and the amount of wax and moisture in the fleece. Results of breeding trials over many years are positive and the work is being scaled up.


Clips give a result similar to mulesing, but without an open wound and with significantly less pain. They prevent blood flow to the skin that would be removed by mulesing. This skin and the clips fall off within a couple of weeks leaving a bare area around the lamb’s breech and tail. Some producers report they feel confident they could stop mulesing and use clips to control flystrike.

Injection into the skin

An injection kills the skin cells, a bruise forms, followed by a scab which falls off. This leaves stretched and bare skin around the breech and tail. The technology is not yet fully developed.

Gene mapping the sheep blowfly

This project involves mapping blowfly genes to find ones that could be useful for fly control. Mapping will be the basis for future work on insecticides or vaccines. There is also the potential for mass release of male blowflies that are genetically altered to be sterile.

Other initiatives

  • There is a project on the control of worms, lice and flies to reduce reliance on chemical control. It uses natural enemies or other biological agents, as finding alternatives is important because pests are becoming resistant to chemicals.
  • The National Mulesing Assurance Program trains and assesses mulesing to a national standard. It is aimed at all contractors and owners who mules sheep. Accreditation teaches operators how to achieve the best health and welfare standards until an alternative to mulesing is found.
  • Woolgrowers now have a simple form when selling wool to certify they do not mules their sheep.
  • There is a post-mulesing topical spray available for the relief of post-mulesing pain, however it is only used on approximately 60% of all sheep being mulesed.

What can be done now?

The key to effectively managing flystrike in the absence of mulesing is an integrated approach to blowfly control. Such an approach includes animal husbandry and farm management practices that take into account the timing of shearing and crutching, the timing of tail docking (should that be required), strategic application of chemical treatments (should they be required) and, importantly, regular inspection of the flock. While ever mulesing is conducted, it should be accompanied by the use of topical pain relief.
Accompanying these strategies with a breeding and selection program that aims to reduce wrinkle and increase the bare area in the perineal region and remove susceptible sheep from the flock, will have a cumulative effect on the flock’s overall resistance to flystrike.

This website provides general information which must not be relied upon or regarded as a substitute for specific professional advice, including veterinary advice. We make no warranties that the website is accurate or suitable for a person's unique circumstances and provide the website on the basis that all persons accessing the website responsibly assess the relevance and accuracy of its content.
Attached files
file Research report - Prevention and control of flystrike August 2011.pdf (166 kb)

Also read
document Why are painful procedures performed without anaesthetic?
document Can the RSPCA prosecute farmers for performing painful husbandry procedures without anaesthetic or pain relief?
document RSPCA Policy B4 Farm animal husbandry and management

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