A new study has investigated the effects of the Dually™ control headcollar
‘The Dually™, patented by horse trainer Monty Roberts is a control headcollar, which states it is designed to improve equine behaviour during handling challenges by applying greater pressure than a standard headcollar.
How the Dually™ Works
The action is caused by a looped rope positioned over the nose, which slides through rings placed either side under the cheek pieces. When the strap is pulled forwards and away from the head this rope strap slides through the rings, shortening and thus tightening on the nose. The consequences of this act on tightening is possible restriction of the muscles (which serve the lips/muzzle), nerves and arteries running underneath this area.
When used from the saddle (some equestrians use this as a bitless bridle – check with your insurance as it is marketed as a halter, it may not be covered on public highways) the rope action seesaws over the nose with right and left commands. if the rider is forceful and pulls strongly on one rein, then the alternate rein will be pulled towards the bridle, stopping at the connecting ring and push in to the side of the face where muscles are sited over the upper teeth (this area is wider that the lower jaw so the muscles are pushed up against the cheek teeth).
The release on this control halter in my experience is slow. As the looped rope is used repeatedly it quickly looses it’s smoothness and it soon needs to be physically released. Another area to draw your attention to is the positioning, because the lower rope loop works over the nose, but cannot be positioned too low down as it would sit on the supported nasal bone area, the usual noseband which is required for stability sits high over the nerve branches and can easily rub on the bottom portion of the cheek bone.
The halter is marketed to be used with pressure release training with the idea that if the method is followed, then the horse will become less resistant and less pressure will be required.
The study ‘Dually™ investigated: The effect of a pressure headcollar on the behaviour, discomfort and stress of trained horses‘ highlighted that:
- Dually™ headcollars increase pressure, intended to improve compliance in horses.
- Horses did not complete handling tests faster in the Dually™, compared to Control.
- Horses tended to refuse more proactively in the Dually™, compared to Control.
- Trained horses refused more proactively than Naïve horses in the Dually™.
- Stress and Horse Grimace Scores were not higher in Dually™ than Control.
The only good news from these highlights are that the grimace scores were not higher than use without the Dually™, however it does call in to question whether the halter really comes through on it’s promise to improve behaviour.
Abstract From the Study
“Previous research indicated it did not improve compliance in naïve horses but did result in higher Horse Grimace Scale scores (HGS) indicative of discomfort. However, subjects had not been trained to step forward to release the pressure applied by the headcollar.
The current study aimed to determine the effect of training on behaviour and physiology of horses wearing the Dually™ headcollar during handling challenges. To this end, subjects received three training sessions prior to completing two handling tests in which they crossed distinct novel obstacles, one wearing a Dually™ with a line attached to the pressure mechanism and one attached to the standard ring as a control.
Behaviour was coded by hypothesis blind researchers: time to cross the obstacle and proactive refusal (moving away from the obstacle) were recorded as indicators of compliance and the Horse Grimace Scale was used to measure discomfort caused by each configuration of the device. Infrared thermography of ocular temperature, heart rate variability (RMSSD and low/high frequency ratios (LF/HF)) and salivary cortisol were measured as indicators of arousal.Data from the previous study on Naïve horses was also included to compare responses to the Dually™ in Naïve and Trained horses. Training resulted in a decrease in RMSSD (p = 0.002) and an increase in LF/HF (p = 0.012), compared to rest, indicating arousal. As per the original study, horses did not complete the tests more quickly in the Dually™, compared to control (p = 0.698). Trained horses from this study tended to be more proactive in the Dually™ compared to Controls (p = 0.066) and significantly more so than Naïve horses from the previous study (p = 0.002) suggesting that behaviour becomes less desirable during early Dually™ training. Yet, stress and HGS indicators were not higher in the Dually™ compared to Control during testing.
Results suggest the Dually™ has a negative effect on behaviour but not on stress or discomfort during short handling challenges. Further research is warranted to determine the long-term effect of Dually experience on behaviour and welfare.”
The full article can be found here www.sciencedirect.com/science/article/abs/pii/S0168159120301891