What is the RSPCA’s view on mulesing and flystrike prevention in sheep?

Mulesing involves cutting crescent-shaped flaps of skin from around a lamb’s breech and tail. When this painful wound heals, it creates an area of bare, stretched scar tissue which has no folds or wrinkles and is less likely to attract blowflies. This makes mulesed sheep less susceptible to flystrike in the breech area. Mulesing is unnecessary if sheep are bred to be flystrike resistant and are appropriately managed.

What is flystrike?

Some sheep, particularly some types of Merinos, have woolly wrinkles and folds in their skin, especially around the tail and breech area (the back and top of the hind legs near the tail). This area can become moist due to skin folds, urine or faeces build up. Blowflies are then attracted to this moist area where they lay eggs. Eggs generally hatch into larvae (maggots) within 12-24 hours. Maggots then feed off the living flesh of the sheep for days — this is called flystrike, which causes sheep pain and suffering and if left untreated, can be fatal.

What is mulesing?

Mulesing is a painful procedure that involves cutting crescent-shaped flaps of skin from around a lamb’s breech and tail using sharp shears designed specifically for this purpose. The resulting wound, when healed, creates an area of bare, stretched scar tissue. Because the scarred skin has no folds or wrinkles to hold moisture and faeces, it is less likely to attract blowflies. Mulesing makes high-wrinkle Merino sheep less susceptible to flystrike in the breech area compared to unmulesed sheep of the same type.

Mulesing is usually carried out during lamb ‘marking’ when the lamb is between 6 to 10 weeks of age. Lamb marking may include not only mulesing but also a series of other painful procedures that are all carried out at the same time: tail docking (removal), castration (removing testicles in male lambs), ear tagging, and vaccinating. Millions of lambs are mulesed each year in Australia.

Mulesing is performed without any prior anaesthesia (numbing), and pain relief after the surgery is not always used. Where post-mulesing pain relief is administered, it usually doesn’t last as long as the pain caused by mulesing lasts. The mulesing operation is quick; however the resulting pain lasts days to weeks [1], and the mulesing wound takes 5-7 weeks to completely heal [2]. Mulesed lambs will socialise less, lose weight in the first two weeks post mulesing, and exhibit behavioural indicators of pain including prolonged hunched standing and less time lying and feeding. The effect on gait and growth may be apparent for up to three weeks following the procedure. Following mulesing, lambs may avoid humans and, in particular, the person who carried out the procedure, for a period of 3 to 5 weeks. This avoidance behaviour is indicative of fear and the extent to which the animal experiences the procedure as aversive. For further information and references, see the RSPCA Research Report: Prevention and control of flystrike in sheep.

Both mulesing and flystrike cause substantial challenges to sheep welfare. Mulesing is a quick and effective method of controlling flystrike in high-wrinkle Merino sheep, hence its popularity with producers. However, mulesing results in poor welfare both during and after the procedure due to the pain it causes.

Is there a humane alternative to mulesing?

There is an effective and humane alternative available to mulesing sheep, which is to breed sheep that are flystrike resistant without the need for mulesing. The time it takes to breed flystrike resistance into an existing Merino herd varies depending on the type of sheep a producer is starting with, how resistance traits are selected for, and the climate that the flock resides in.

While some producers may be able to transition their flocks to become non-mulesed through good breeding within a few years, it is estimated that other flocks may take up to 10 or more years [3]. However, the wool industry has had ample time to transition all flocks to become non-mulesed, as the genetic alternative to mulesing has been known about for decades. Despite this, breeding sheep for flystrike resistance has not been prioritised by the wool industry or by many wool producers over the years. This has resulted in a large proportion of Australian Merinos continuing to be mulesed despite there having been plenty of time to breed flystrike resistant, non-mulesed sheep.

Effects of climate change on flystrike risk

Climate change is likely to increase the risk of flystrike due to prolonged fly seasons [4]. This makes breeding for flystrike resistance in sheep even more urgent.

What is the RSPCA’s position?

The RSPCA believes that it is unacceptable to continue to breed sheep that are susceptible to flystrike and therefore require mulesing or other painful procedure to manage flystrike risk.

The RSPCA urges the wool industry to continue to invest in comprehensive on-farm extension efforts to facilitate the rapid adoption of breeding solutions to mulesing.

The RSPCA urges retailers sourcing Australian wool to indicate to suppliers their intention to purchase only non-mulesed wool within the shortest possible time frame, noting that such wool should be sourced from flystrike-resistant sheep.

In the meantime, the wool industry must demonstrate progress in the adoption of improved management and breeding practices, i.e. a steady and significant decline in the number of sheep being mulesed (or subjected to another painful procedure to manage flystrike) as a proportion of the total flock (Merinos versus non-Merinos).