My friend (let’s call her Anne for the purposes of this article) shows two horses in the jumper division at the bigger shows. She is a rock star amateur, rides like a professional, and had been competing her smart and careful 10-year-old mare successfully in the 1.30 m. So I was naturally surprised when she said she was retiring her.

“She just doesn’t want to jump anymore,” she said. The mare had become increasingly anxious and began stopping; they had dropped her down a division, and another, but she continued to stop.

The trainer suggested that, like many extremely careful horses, Anne’s mare was unforgiving about an amateur’s mistakes and was really a ‘professional’ ride. I was unconvinced. Anne rarely misses a distance, has a strong relationship with her horse, they have been together for five years, and the mare undoubtedly does more for her than she would for a professional.

A vet workup revealed no lameness, so a physiological cause was ruled out. The trainer was keen to try medication to take the edge off her “blood”, but Anne was not going down that road and decided to retire her from jumping and breed her. Since the mare would undoubtedly have a happier life as a broodmare than a show horse, I didn’t push it, but in my heart I knew there was a good reason why a keen, talented horse, who seemed enthusiastic about her job, simply didn’t want to play anymore.

Here I discuss some plausible sources of a horse’s deteriorating performance, both physiological and psychological, and why we might miss some of these obvious (and not so obvious) red flags when they do appear.

Physiology behind the “No”

Lameness is the typical behavioural indicator to alert us to pain severity, but this may not always be the best predictor of tissue damage and/or the extent of an animal’s suffering. In an assessment of 21 horses with existing lameness issues, equine scientist Carrie Ijichi and colleagues (2014) found no relationship between horses’ actual tissue damage (rated by equine practitioners from radiographs and ultrasound) and the degree of lameness exhibited in a trot-up. In fact, personality correlated with lameness ratings rather than tissue damage. Horses that were more extroverted were more likely to show lameness, suggesting that their introverted counterparts may often suffer silently and remain undiagnosed.

Dr. Sue McDonnell, director and founder of the New Bolton Center’s Equine Behavior Lab at the University of Pennsylvania, notes that 90% of their horses referred for a behavioural problem have a physiological root cause. These physiological issues can be tricky to detect and are often missed in the typical and relatively brief veterinarian lameness workup.

McDonnell routinely puts all their new cases under 24-hour video surveillance, finding that many behavioural clues not apparent during the daytime activity at the clinic appear during the quiet night hours. When the video footage is played back at higher speed, patterns emerge (e.g., constant weight shifting, or nosing at the groin or stomach) and can help uncover subtle physiological issues that may be the source of a behaviour problem. Interestingly, once remedied, the problem behaviours disappear. McDonnel notes that horses, unlike humans, are unlikely to hold a grudge (2013, ISES Conference, University of Delaware).

Research by Dr. Sue Dyson has revealed that horses may be experiencing pain more often than we think. Over a long-term study spanning several years, assessing horses of different breeds and disciplines, Dyson’s research group developed the Ridden Horse Pain Ethogram (RHpE), to predict musculoskeletal (MSK) pain that may not be obvious to even an experienced eye. The RHpE examines horses under saddle and identifies 24 behaviours often characterized as normal (tail swishing, tripping, dragging a toe), training issues (head tilt, mouth opening, consistently picking up a preferred canter lead, becoming disunited, or falling out of the canter) or naughty (laziness, ears back, head tossing, rearing, bucking).

Transport stress, solitary confinement, and anti-inflamatory medication or NSAIDS make it little wonder that EGUS has been called a human-created disease.

Dyson’s group found that almost all of the 24 behaviours are at least 10 times more likely to occur in lame horses than in sound ones (2018). Horses with a score greater than 8/24 were clearly experiencing MSK pain, but some horses with scores of less than 8/24 were also found to be in pain. Furthermore, when horses were temporarily nerve-blocked to alleviate pain, their RHpE scores were immediately and significantly reduced, suggesting that MSK pain was causing these behaviours (Dyson et al., 2018b; Dyson and Van Dijk, 2020, Dyson, 2023).

Dyson maintains that many behaviours that we consider typical, a hole in training, or a personality flaw, are often manifestations of pain. Even behaviours that we have insidiously come to see as normal during tack-up (e.g. teeth grinding, tail swishing, pawing, etc.) could be a horse anticipating the pain that will come when under saddle.

Another source of pain and potential performance deterioration not apparent in the typical lameness work-up is Equine Gastric Ulcer Syndrome (EGUS), the result of an imbalance between the protective and acid-producing functions of the stomach. Horses, with a gut designed for almost continual grazing, produce gastric juices constantly (up to nine gallons of acidic fluid per day). When there is no buffering food in the stomach, the protective stomach tissue is eroded (Neito et al., 2004).

Other risk factors for EGUS (transport stress, solitary confinement, and anti-inflamatory medication or NSAIDS) make it little wonder that EGUS has been called a human-created disease. Given that EGUS is so prevalent in show horses – plus or minus 80% (e.g. Lutherrson et al. 2009), has been found in 100% of race horses (Hyeshin Hwang et al., 2022), and has even been found in 40% of pleasure horses who presented no clinical symptoms (Niedzwiedz, et al., 2014), the potential impact of ulcers on performance cannot be understated.

Many show stables administer ulcer medication as part of regular horse show routine. However, research suggests that medication will have only short-term impact without a simultaneous revolution in management (e.g. van den Boom, 2022) – management changes that are seldom afforded to sport horses such as increased access to movement, forage, and tactile contact with other horses. In a study of 14 mares with severe stomach ulcers (half of whom received ulcer medication and controls who did not) Lieuwke Kranenburg and colleagues found that management changes overshadowed any potential impact of medication. They noted that severe ulcers can improve and heal without medication with the provision of 24/7 access to hay and a small amount of low-starch concentrate. (See also Böhm, S. et al., 2018 for similar findings underscoring the impact of an ad libitem forage diet in healing ulcers).

Psychology behind the “No”

More subtle still are the psychological reasons why a performance horse may lose the capacity to do their job well. Although there is a wealth of information about the deleterious impact of single stall housing, it remains the norm in most of today’s sport horse stables. The research is robust and conclusive. Compared to horses housed individually, group or pair-housed horses show significantly lower levels of physiological stress (e.g. Yarnell, et al, 2015), demonstrate fewer stress-related behaviours (e.g.Visser et al., 2008), and are less likely to develop stereotypies (Heleski et al., 2020; Ruet et al., 2019; 2020). They are easier to handle (Yarnell et al, 2015), learn more quickly and retain the learned material longer (Ladewig, 2004), and demonstrate more sophisticated abilities in comprehending and responding to human gestures (Lansade et al., 2023).

In contrast, singly housed horses are more likely to demonstrate behaviours characteristic of human depression such as a withdrawn posture, disengaged attitude toward their environment (Ruet et al., 2019; Ruet et al., 2020), and anhodenia, or loss of pleasure in normally pleasurable activities (Furieux et al., 2012). Ironically, the primary goal of individual housing – to protect horses from injury – is not successful. Individually housed horses show higher incidences of lameness (Giupana et a.l 2017; Sanmartín Sánchez, et al. 2020), sustain more lower-limb injuries (Sanmartín Sánchez, et al. 2020), and have higher incidents of tendon, joint, and health problems (Popescu et al., 2019) than group-housed horses.

A horse alone in its stall.

Although there is a wealth of information about the negative impact of single-stall housing for horses, it remains the norm in most stables. (scandamerican –

Less research has explored how single stall housing may or may not impact performance. I had an opportunity to speak about the limitations of our modern management systems with Andrew McLean, equine scientist, ethologist, and CEO of Equitation Science International and working equitation and dressage trainer Jody Hartstone in a podcast we did for the International Society of Equitation Science. I posed the question that while were we able to address all of a horse’s ethological needs at home, how do we then manage those needs when we take them to horse shows where stressors are increased (routines disrupted, increased time in the stall, greater social isolation, transportation stress, sleep disturbances, and the stress of competition itself).

Andrew replied that it is precisely by instilling a good welfare state at home that fosters the security a horse needs to handle the temporary challenges of horse showing. He noted that, contrary to common horse wisdom, a horse that lives in a herd and has developed strong attachment bonds to particular others will carry that felt security away from home and demonstrate greater resiliency and resources to cope with the added stressors encountered there.

Jody talked about one of her clients who insisted her horse should live on his own to ensure that he would not become herd-bound. Jody replied that exactly the opposite was true. The more secure a horse can feel that their buddies will reliably be there upon their return, the more confident that same horse can be to venture out alone.

In human attachment systems, a secure attachment with an established and preferred attachment figure gives us the confidence, or secure base, to explore the world, knowing that we have that touchstone to return to whenever needed. We want to stay close to our attachment figures (at least by text if they are not physically present) and we feel some anxiety when separated from them without that contact. We also use this same attachment figure in times of threat as our safe haven – the person we turn to when something terrible happens (Bowlby, 1980, 1982).

We do not have the same wealth of research as to how attachment systems work in horses. However, we can presume that as social animals who show distinct preferences and a desire to be close to particular others, appear to use those others as a secure base from which to explore and a safe haven in times of threat, that many of the same key characteristics of human attachment are at play. They also show separation distress when that particular other is permanently removed, and demonstrate what certainly looks like grief upon loss of that particular friend.

Allowing for tactile as well as visual contact between compatible stall-mates will go a long way toward fulfilling horses’ social needs…

Andrew remarked that when social isolation was addressed for the Manchester Police Force horses in London by creating stall openings between compatible neighbours so that horses could interact and groom one another, there was a radical transformation for those horses out on patrol. The horses were braver, shied less, and showed a renewed enthusiasm for their work that was not apparent for the horses who continued to be housed in traditional stalls with no tactile contact between neighbours.

Andrew’s observations corroborate other studies that suggest we do not need to turn our show horses out on the range to meet their social needs, improve their welfare, and possibly expand their resources and resiliency for coping with other stressors. For example, Swiss researchers Anja Zollinger and colleagues (2023) explored the impact of the “social box” comprised of openings in vertical bars that allowed stallions to put their head, neck, and legs into the adjacent stall. Compared to the conventional box (grilled upper and solid lower walls between horses), horses in the social box interacted much more often (114 social interactions vs. 24, in a 24-hour period) and no serious injuries were reported.

The authors concluded that the social box allows horses (in fact, stallions!) to interact in a safe way with minimal risk of injury and reduces the physiological and psychological stress of conventional individual stabling. Allowing for tactile as well as visual contact between compatible stall-mates (removing electric wire between turn-outs, lowering partitions between stalls to create grooming opportunities, or making openings in solid wall partitions) will go a long way toward fulfilling horses’ social needs without involving a paradigm shift in current equine housing.

What we may be seeing in the performance horse who one days says ‘no’ is that our management practices of social deprivation with limited opportunities for movement, foraging, and agency leaves horses with a dearth of coping resources. Although they may appear to be managing, they may be pushed beyond that threshold when more stressors are added.

Lansade and colleagues (2014) found that young Welsh ponies housed in an enriched environment (with daily pasture turnout in a herd) demonstrated fewer stress-related and more relaxed behaviours, were significantly calmer, less fearful, less reactive, less sensitive, more interactive with humans, and showed more adaptability in a learning task than ponies housed in an impoverished environment (living in stalls and turned out in individual paddocks 3xs per week). Differences were still apparent three months after the end of treatment when all youngsters resumed their former herd life. In general, ponies in the enriched condition retained this positive perspective, demonstrated a higher level of curiosity and superior learning performance than ponies who experienced the control condition, a resilience that carried on well after the study’s end.

Sadly, our current sport horse stables look very much like Lansade’s “impoverished condition” and may well be leaving our show horses operating at a deficit that leaves nothing in the bank when we make the large draw of a five-to-seven-day horse show.

Our investment in ignoring the “No”

One might argue that most of our individually housed horses don’t appear to be suffering. I would counter that horses’ suffering is not obvious (it makes good evolutionary sense for horses as prey animals not to advertise their pain, so their “stoicism” may be real and adaptive). Also, we are poor detectives and it is not in our best interests to go digging for problems.

It is a tough call when a capable horse who has been stepping up to the plate every day to play our game just one day says “I’m not in.”

Lesimple and Hausberger (2014), for example, found huge discrepancies between caretakers’ reports of the prevalence of stereotypies such as weaving, cribbing, and stall walking (5% prevalence) and the researchers’ on-site behavioural observations (37% prevalence). Indeed, across numerous studies, the prevalence of stereotypies according to questionnaire surveys range between 1 and 10%, while observational studies, where researchers monitor and record stereotypies in the stable, report rates of 22% to 96% (Lesimple et al., 2016).

Social psychologists have researched extensively the cognitive gymnastics in which we engage when what we believe and what we do are at odds, so that we can disengage, downplay, normalize, sanction, or even feel proud of behaviours that we know in our hearts to be morally unjustified (e.g. Bandura, 1999). Most of us who own and ride sport horses know that we are falling short in meeting their ethological needs – needs that could be satisfied were they to live in a more natural environment. Sadly, many of us do not have the opportunity to affect radical or even modest change when boarding at show stables that offer little owner autonomy, especially with ideas that would so thoroughly challenge the industry norm.

It is a tough call when a capable horse who has been stepping up to the plate every day to play our game just one day says “I’m not in.” My friend Anne took the high road and honoured her horse. She said, “Okay, thank you. You gave me a great ride. You don’t have to do this anymore.” The mare is now living outside with a group of broodmares and expecting her first foal this spring.

Undoubtedly, not all of us will have the resources to make the same call. However, Anne’s story was my wake-up call, reminding me of the extraordinary ask I make of my horse every single day, that I need to never take it for granted, that I should be filled with awe and wonder every time she steps into the trailer, and that I should listen to whatever she tries to tell me and try to accommodate it in the best way I can.