Despite domestication and careful management, horses retain many of their innate flight and fright behaviours in response to environmental challenges. Consequently, the use of equipment to manage and reduce the likelihood of potentially dangerous behaviours in a domestic setting is often employed.
Pressure headcollars are often anecdotally reported as being useful to manage equine behaviour. They work by applying pressure to specific areas of the head when an animal presents undesirable or resistant behaviours. Once the desired behaviour occurs, pressure is released. This means that horses can be trained using such equipment via negative reinforcement – the removal of unpleasant stimuli when a desired response is achieved. Pressure on sensitive facial areas however, can raise wellbeing concerns (1), and previous work has suggested that pressure headcollars did not improve behaviour in untrained horses but did increase facial pain scores (the Horse Grimace Scale; HGS), an indication of discomfort (2).
A recent study aimed to further examine the effect of a commercially available pressure headcollar (the Dually™) on stress, discomfort and the behaviour of horses3. The Dually™ can be used in two ways; via an under-the-jaw attachment as in conventional headcollars, or by a pressure application and release system around the jaw and nose which is controlled by the handler.
Study horses (6 mares, 10 geldings) were trained using the Dually™ in three sessions, for specific behaviours; stop, stepping-forward, accelerate, decelerate and backing-up. This was followed by two handling tests over different ground obstacles: one test using the pressure controlling system, the other using the conventional attachment chin ring (‘control’ condition). Video footage was taken of the handling tests for subsequent behaviour analysis by researchers unaware of the study hypothesis. HGS scoring was used as an indication of discomfort, and overall physiological state was assessed by salivary cortisol levels, infrared thermography of eye temperature and heart rate variability. Results from the trained horses were also compared to results obtained in a previous study (2) examining the Dually™ effects on untrained horses.
The Dually™ did not increase the speed of task compliance compared to the control setting in study horses (p = 0.698). However, “proactive” behaviour that involved horses refusing to complete the test was higher in the trained Dually™ situation than the control condition (p < 0.066) or in “untrained” horses (p = 0.002). This suggests the Dually™ may have a negative effect on compliance following training and that training might increase resistant behaviour. Measures of stress and discomfort, however, were not significantly different between the control and pressure- controlling situations, indicating that increased stress or discomfort was not experienced in Dually™ trained horses compared to conventional headcollars. Consequently, the use of pressure-headcollars may not compromise equine wellbeing although notably, their use appeared not to improve compliance with specific tasks, even after training.
References
1. McGreevy, P., Warren-Smith, A., and Guisard, Y. (2012). The effect of double bridles and jaw-clamping crank nosebands on temperature of eyes and facial skin of horses. J. Vet. Behav. 7, 142–148. Available HERE
2. Ijichi, C., Tunstall, S., Putt, E., and Squibb, K. (2018). Dually Noted: The effects of a pressure headcollar on compliance, discomfort and stress in horses during handling. Appl. Anim. Behav. Sci. 205, 68–73. Available HERE
3. Ijichi, C., Wild, H., Dai, F., Bordin, A., Cameron-Whytock, H., White, S.J., Yarnell, K., Starbuck, G., Jolivald, A., Birkbeck, L., Hallam, S. and Dalla Costa, E. (2020). Dually investigated: The effect of a pressure headcollar on the behaviour, discomfort and stress of trained horses. Appl. Anim. Behav. Sci. 232, 105101. Available HERE