Barrier Frustration in the Stabled Horse

Stall kicking and pawing are two undesired behaviours observed in stabled horses. There is uncertainty as to whether they represent true stereotypic behaviours or may be more accurately classified as unwanted behaviours arising in response to barrier frustration, which occurs when the expression of normal, species-specific behaviours is hindered (McGreevy, 2012; Nakonechny, 2017; Pascoe & Houpt, 2015).

Using the example of a horse that frequently paws at the ground and kicks the wall when confined to a stall, this post examines the various reasons that could cause these behaviours with an emphasis on the effects of stall confinement on the horse and potential solutions.

Seasonal housing arrangements & observed behavioural changes

From mid-May until the end of October, the horse under observation, let’s call him Henry, is turned out at pasture with one horse and has a view of 6 to 12 other horses in adjacent fields. Come late-October all of the horses, with the exception of a small group-housed herd, are moved into stalls and receive infrequent turnout in individual gravel paddocks. Once in the stable, Henry begins to exhibit frequent pawing and kicking behaviours. He is housed in one of the most isolated stalls in the stable, a small, dark, corner box stall that limits his view of conspecifics to two neighbours, neither of whom he has any tactile contact with. The stall has floor to (nearly) ceiling walls on 3 sides with bars across the front. When in his stall, Henry appears to have a high level of restlessness in comparison to the other horses in the stable, and in addition to the pawing and kicking, is avoidant when anyone approaches. However, he is very calm and curious when in the pasture, approaches the fence when people walk by and enjoys being pet.

Potential causes of the unwanted behaviours

There are a number of factors that have been associated with pawing and stall kicking in horses, including communication, pain or physical discomfort, anticipation of food, and barrier frustration.

If a horse kicks against a shared wall, it may be communicating with a neighbour “in a show of antipathy” (Pascoe & Houpt, 2015, p.43). However, if the kicking is rhythmic and repetitious it may be viewed as a locomotor stereotypy or be a sign of frustration. Both pawing and stall kicking can become reinforced learned behaviours if the horse habitually performs the behaviour in anticipation of food and is fed while the behaviour is occurring. In such cases, it is advisable to wait until the horse takes a break from the activity and is given food only when standing quietly. In many cases, this will extinguish the behaviour because it is no longer being rewarded. Although, a period of more frequent pawing or kicking may occur before complete cessation, as a result of the frustration effect when feeding is delayed (Mason, Clubb, Latham & Vickery, 2007; McGreevy, 2012).

If a horse digs a hole to stand in, it is thought to be trying to alleviate pain or physical discomfort by redistributing its weight (Pascoe & Houpt, 2015), in which case a thorough veterinary examination should be done to rule out health issues.

Barrier frustration occurs when horses are prevented from carrying out species-specific behaviours such as feeding, locomotion and socialization. Unfortunately, the ability to meet these needs adequately in modern, individual housing arrangements is often insufficient, resulting in unwanted behaviours that can often be misdiagnosed as locomotor stereotypies  (Hothersall & Casey, 2012; McGreevy, 2012).

Physiological & behavioural effects of confinement

A horse’s behaviour is always telling us something (Merkies, 2017). In the case of Henry, with health issues, food anticipation and communication ruled out, and given the seasonality of the behaviour, it is reasonable to presume that the kicking and pawing are related to barrier frustration from stall confinement, which is a common underlying cause of stereotypies and other similarly perceived behaviours (Hothersall & Casey, 2012; McGreevy, 2012). Having evolved to actively forage in a herd for 16 to 20 hours a day, horses respond poorly to isolation and may exhibit increasing signs of physiological and behavioural distress relative to time spent in a stall and/or decreased contact with conspecifics  (Hartman, Sondergaard & Kelling, 2012; Hothersall & Casey, 2012; McBride & Hemmings, 2005; McGreevy, 2012; Sarrafchi & Blokhuis, 2013).

Welfare concerns

Behavioural changes are often an early indication of suboptimal conditions (Sarrafchi & Blokhuis, 2013). Whether true stereotypic behaviours or behaviours arising from barrier frustration, the welfare concerns and potential solutions in this case are similar. Environmental modifications and appropriate behaviour modification techniques to mitigate the causes of the pawing and stall kicking should be implemented as early as possible, before the horse sustains an injury or the behaviour becomes more severe and ingrained (Hothersall & Casey, 2012).

Solutions

Working within the confines and standard protocols of the stable where the horse is housed, potential solutions to lessen the effects of confinement include increased stimulation, increased foraging opportunities, and where possible, increased social contact and turnout. Increasing stimulation can be as simple as placing a mirror in the stall. It is unclear whether horses recognize themselves in mirrors or simply perceive there to be another horse within close visual contact. Either way, placing a mirror in the stall of a confined horse appears to provide an adequate degree of stimulation to counteract the ill effects of isolation (Cooper & Albentosa, 2005; McGreevy, 2012; Sarrafchi & Blokhuis, 2013). If the need for increased turnout can be easily met, this can have immediate and significant benefits by fulfilling the horse’s need for locomotion and foraging. Failing that, taking steps to increase foraging opportunities while stalled may be the next best thing with the provision of multiple forages or an appropriate foraging device (Hothersall & Casey, 2012).

Being very social creatures, the ideal solution is to increase social contact with other horses. As McGreevy (2012, p. 158) writes “horses have a behavioural need for tactile communication” and “abnormal behaviours are commonly associated with stable designs that deny tactile communication between neighbours”. As such, close visual and tactile contact with another horse, even if only through bars separating neighbouring stalls has been proven to lower the incidence of undesired behaviours in stabled horses (Cooper & Albentosa, 2005; McGreevy 2012). This is frequently avoided because owners and stable managers fear that horses may fight or injure one another. However, unwanted behaviours and conflicts between neighbouring horses can be minimized if stable managers make an effort to stable horses “that have demonstrated some affiliation in the paddock” beside one another (McGreevy, 2012, p. 141).

Conclusion

In determining the cause of any unwanted behaviour, physical health, socialization opportunities, food anticipation and other potential sources of frustration should be examined and adjustments made to correct for any suboptimal housing conditions, while maximizing opportunities for stimulation, turnout, foraging and social contact. “Just as health is characterized primarily by the absence of disease, welfare can be characterized partly by the absence of abnormal behaviour or behaviour problems. Consequently, just as treatment and prevention of disease improves health, treatment and prevention of behaviour problems can improve welfare” (Ladewig 2005, p.183).

References

Cooper, J. & M. Albentosa. (2005). Behavioural adaptation in the domestic horse: potential role of apparently abnormal responses including stereotypic behaviour. Livestock Production Science, 92, 177-182

Hartman, E., Sondergaard, E., & Kelling, L.J. (2012). Keeping horses in groups: A Review. Applied Animal Behaviour Science, 136 (2-4), 77-87.

Hothersall, B. & R. Casey. (2012). Undesired behaviour in horses: A review of their development, prevention, management and association with welfare. Equine Veterinary Education, 24 (9), 479-485.

Ladewig, J. (2005). Of mice and men: improved welfare through clinical ethology. Applied Animal Behaviour Science, 92, 183-192.

McBride, S. & A. Hemmings. (2009). A Neurologic Perspective of Equine Stereotypy. Journal of Equine Veterinary Science, 29 (1), 10-16.

McGreevy, P. (2012). Equine Behaviour: A Guide for Veterinarians and Equine Scientists, 2nd ed. Edinburgh: Elsevier.

Mason, G., Clubb, R., Latham, N. & Vickery, S. (2007). Why and how should we use environmental enrichment to tackle stereotypic behaviour? Applied Animal Behaviour Science, 201, 163-188.

Merkies, K. (2017, February 9). Group 4 – Question 3. [Online discussion]. Message posted to https://courselink.uoguelph.ca/d2l/le/449471/discussions/threads/1986368/View

Nakonechny, L. (2017, February 9). avoidance behaviour. [Online discussion]. Message posted to https://courselink.uoguelph.ca/d2l/le/449471/discussions/threads/1977264/View

Pascoe, E. & Houpt, K. (2015, February). Horses Behaving Strangely: learn the reasons behind many puzzling horse behaviours and what you can do to manage them. Practical Horseman, 43 (2), 43-49.

Sarrafchi, A. & Blokhuis, H.J. (2013). Equine stereotypic behaviours: Causations, occurrence and prevention. Journal of Veterinary Behaviour, 8, 386-394.