Electro-immobilisation is a restraining method that runs a low-voltage electrical current down the animal’s spine to induce temporary paralysis, thereby preventing voluntary movement (Grandin, 1986; American Veterinary Medical Association, 2008). The electrical current does not reach the brain; this means, the animal remains conscious and sensitive to pain during the procedure and can only restore its mobility once the current is switched off (Sub-Committee to the Scientific Advisory Committee on Animal Health and Welfare, 2005). Electro-immobilisation is mostly used in the livestock sector, particularly in cattle, to perform painful husbandry procedures such as dehorning, castration and branding. It is usually applied in conjunction with traditional methods of restraint such as squeeze chutes or head gates (Sub-Committee to the Scientific Advisory Committee on Animal Health and Welfare, 2005). The use of electro-immobilisation is common among Australian farmers and users argue that electro-immobilisation improves safety for both handlers and cattle, produces immediate recovery for the animal and increases the speed at which husbandry procedures can be carried out (Cattle Standards and Guidelines Writing Group, 2013).
Methods of electro-immobilisation
Electro-immobilisation was first introduced as a wired device, with two cabled electrodes (clips) attached to the animal’s body. One clip is attached to the ear or nose and one is attached to the caudal fold of the tail using a needle, which may be painful to the animal. The clips are connected to an external battery that delivers an electric current down the spinal column, resulting in temporary immobilisation. This method is less practical as the two clips at opposite ends need to be fitted before any effect is seen. In addition, wires can easily get tangled or get pulled off, resulting in an unrestrained animal (Mitchell Engineering Food Equipment, 2017).
Most recent electro-immobilisation devices are wireless. They require the application of a single probe placed into the animal’s anus, and the electrical current is controlled by a switch attached to the probe. This method is more practical and popular among farmers as there are no wires or external battery and the immobilisation is immediate (Mitchell Engineering Food Equipment, 2017). While welfare implications of wireless devices are under research, the animal’s stress and pain response to the application of electric current would be similar in both wired and wireless devices (Cattle Standards and Guidelines Writing Group, 2013).
Animal welfare implications of electro-immobilisation
Research has shown that electro-immobilisation is aversive to animals (Carter et al., 1983; Lambooy, 1985; Grandin, 1986; Rushen, 1986; Rushen and Congdon, 1986; Sub-Committee to the Scientific Advisory Committee on Animal Health and Welfare, 2005).
The main welfare implications are that the practice
- May cause difficulty breathing followed by suffocation. There have been some reports of death associated with the use of electro-immobilisation, presumably from lack of oxygen due to respiratory paralysis, combined with an abnormally high heart rate.
- May cause profound cardiac effects.
- Prevents the animal from appropriately responding to pain and distress due to temporary paralysis (the device does not prevent pain or provide pain relief).
- May reduce the incentive for pain relief use during painful procedures.
- Can impact the affective (emotional) state of animals, producing damaging emotional experiences.
- May encourage misuse with inappropriate facilities and prolonged use.
RSPCA Australia opposes electro-immobilisation to prevent voluntary movement of animals
Electro-immobilisation is not justifiable on welfare grounds. RSPCA Australia is opposed to the use of electro-immobilisation in conscious animals, and only supports the use of humane restraining methods that do not cause unnecessary injury, pain, suffering or distress (RSPCA, 2018).
The handling and restraining of animals must be performed in appropriate facilities where animals can be safely restrained, and workers can securely perform management and husbandry procedures. Electro-immobilisation should not be used as a substitute for inadequate handling facilities such as poor yards and races (Grandin, 1986). In cattle, humane alternatives such as good quality squeeze chutes or head gates that allow handlers to vaccinate, dehorn and perform other necessary practices are preferred over electro-immobilisation, which causes unnecessary distress and potentially death to animals (Grandin et al., 1986).
American Veterinary Medical Association (2008) Welfare implications of electroimmobilization. Retrieved on 23 October 2018 from https://www.avma.org/KB/Resources/LiteratureReviews/Pages/Welfare-Implications-of-Electroimmobilization.aspx.
Carter PD, Johnston NE, Corner LA et al (1983) Observations on the effect of electro-immobilisation on the dehorning of cattle. Australian Veterinary Journal 60(1):17–19.
Cattle Standards and Guidelines Writing Group (2013) Cattle Standards and Guidelines – Electro-immobilisation discussion paper. Retrieved on 23 October 2018 from http://www.animalwelfarestandards.net.au/cattle/consultative-process.
Grandin T (1986) Electro-immobilization is NOT a humane method of restraint. Retrieved on 20 October 2018 from https://www.grandin.com/humane/electro.html.
Grandin T, Curtis SE, Widowski TM et al (1986) Electro-immobilization versus mechanical restraint in an avoid-avoid choice test for ewes. Journal of Animal Science 62(6):1469–1480.
Lambooy E (1985) Electroanaesthesia or electroimmobilisation of calves, sheep and pigs by the Feenix Stockstill. Veterinary Quarterly 7(2):120–126.
Mitchell Engineering Food Equipment (2017) Wireless Animal Immobilisers – Improving safety in the agricultural industry. Retrieved on 23 October 2018 from https://www.mefe.com.au/blog/wireless-animal-immobilisers.
RSPCA (2018) RSPCA Policy B4 Handling, husbandry and management. Retrieved on 23 October 2018 from https://kb.rspca.org.au/knowledge-base/rspca-policy-b4-handling-husbandry-and-management.
Rushen J (1986) Aversion of sheep to electro-immobilization and physical restraint. Applied Animal Behaviour Science 15(4):315–324.
Rushen J, Congdon P, (1986) Sheep may be more averse to electro-immobilisation than to shearing. Australian Veterinary Journal 63(11):373–374.
Sub-Committee to the Scientific Advisory Committee on Animal Health and Welfare (2005) The use of electro-immobilisation on live farm animals in Ireland.