Equine Science!

Equines and science! On hiatus.

[black-thoroughbred]

Noseband Tightness Study: The Two-Finger Rule Is Just About Right – The Horse

Researchers found zero-finger tightness equaled 10 times the tightness of a human limb tourniquet.

“Our pressure readings at half-finger and zero-finger tightness literally went off the screen, and we thought our system was malfunctioning,” said Orla Doherty, MVB, MSc, PhD, MRCVS, of the University of Limerick, in Ireland, and hon. president of the International Society for Equitation Scientist (ISES).“We kept repeating the experiment, thinking, ‘We can’t possibly be subjecting live animals to that kind of pressure!’” Doherty told The Horse. “But actually, we are. Every day and at every competition.”

[great-and-small]

Fight me horse people

[mylittlehony]

So the two talks by Dr Brooks and Dr Cosgrove at the Al Khamsa spring meeting were mind-blowing for me, because, well, I simply was not aware of how far technology has come and what is now available to us for the management of our horses’ health. I am still recovering, in particular, from learning that testing of any individual horse’s genome is now commercially available, and also from the figure shared above, which is incredibly exciting. 

The figure comes from the paper by Cosgrove et al. 2020 (open access link) on the genomes of the Arabian. To explain what you are seeing there, every single one of those 312 vertical bars is the genome of a horse. Each different colour represents a different founder population, so the more colours in any given vertical bar/genome, the more genetic diversity is present in that individual horse’s genome. 

On the far right, the mostly blue horses are Thoroughbreds, while the solid mustard-coloured block next to it are Icelandic horses, both used as outgroups, i.e. reference groups not part of the groups being analysed, as are the Turkemen horses next to the Icelandics. 

So here we can see that the Icelandic is pretty homogenous, which makes sense, as it has been isolated longer than any other breed that I can think of. The Thoroughbred is also very homogenous, thanks to intense selection pressure for speed and registry requirements regarding ancestry. Some Thoroughbreds have slightly more diverse genomes - there’s one horse, towards the left of the Thoroughbred cluster, which shares most of its genes with the general Thoroughbred population, but also has a small patch of mustard colour in its column, as well as brown and some red. So this particular individual has inherited DNA from four founder populations. 

The Turkemen horses, by contrast, have more diversity than either the Thoroughbred or the Icelandic, with individuals expressing DNA from up to, I think, nine founder populations. 

So, with the outgroups for comparison out of the way, now we can get down to the nitty-gritty and the fun stuff with the Arabians. To the surprise of absolutely no-one, I am going to start with the desertbred groups. 

Immediately, we can see that the horses from the cradle countries (plus Tunisia) are genetically diverse. The horses from Saudi Arabia have the least diversity, while the Syrian horses have the most. Unfortunately, there are very few samples for these horses - you can see there are only two vertical columns, thus two horses, in the Syrian group. However, this diversity agrees with the findings of Khanshour et al. 2013 and Almarzook et al. 2017. It also makes sense, as these are the horses from the homelands of the Arabian, while the Arabian populations outside the desert have been limited to an extent by the founder effect, i.e. the reduction in variation that results from a smaller sub-set of the wider population creating new satellite colonies. For instance, the Davenport Arabians trace back to the twenty-seven horses that Homer Davenport imported to the US in 1906; not all of those twenty-seven bred on, and several of them were closely related, being siblings or parents and offspring. So on paper the Davenport horses have twenty-seven founder genomes at most to play with, but in practice they have rather fewer. 

The diversity we see among the desertbred horses is also indicative of the Arabian in its home being almost more of a landrace than a breed with a set type. Increased genetic diversity leads to increased heterozygosity, which means that it is harder to fix a specific physical type or standard. So there are big Arabians and small Arabians in their homelands, chunky Arabians and more refined Arabians, Arabians that are faster over shorter distances and Arabians that are faster over longer distances, and so on and so forth. The greater diversity also tells us that these are the original populations, and that the horses still in the desert today bear a close genetic resemblance to their ancestors.

The next group I want to look at are the Polish horses. 

Unsurprisingly, the Polish horses are less diverse, in general, than the desertbreds, with the pink population from the desert horses dominating. Some Polish horses are more diverse than others - the ones towards right of the centre of the Polish block have more colourful genomes, so more populations. In fact, the horse to immediately to the right of the centre of the block has eight colours in its genome, so is genetically very valuable. None of the Polish horses sampled show any of the Thoroughbred blue, despite their historical selection for racing performance. The prevalence of pink in the Polish horses may indicate founder effect (in this case probably due to the effects of the two World Wars), or may indicate selection for specific traits considered desirable in these horses, or be a mixture of both. 

Of the Arabian breeding groups studied by Cosgrove et al., the one with the least diversity is the Straight Egyptian. 

While some of these horses still have quite a few different blocks of colour in their genomes, these blocks are incredibly minute, and with each new generation, they become smaller, or are simply not handed down, by the chances of genetic recombination. The genomes of these Straight Egyptians show intense selection for the teal population, and several of the horses to the right of this group have absolutely no diversity at all. They are entirely teal. The DNA from other ancestral groups has been obliterated. 

This has two effects. Both are the results of the increased homozygosity. For breeders, homozygosity helps to fix type and make the outcome of any match more predictable. When you have fewer genes to play with, there are fewer ways in which they can recombine, so fewer genotypes available. 

On the other hand, homozygosity increases the incidence of recessive diseases in a population. Lavender Foal Syndrome is a known Straight Egyptian issue: this is why. Other Arabian diseases are found frequently in Straight Egyptian bloodlines, again because of their increased homozygosity. Without diversity, not only are the horses vulnerable to disease, they are also vulnerable to inbreeding depression, i.e. fertility problems. The Straight Egyptian is going the way of the Friesian, with its multitude of health issues and reproductive problems, or, to take a human analogy, the way of the Spanish Hapsburgs. 

There is so much I want to talk about here - the great big middle section of multi-origin Arabians, mostly US-based, for instance, showing the contributions of the variety of founder populations, most strikingly the pink and teal associated with Polish and Straight Egyptians, as well as salmon and baby blue, which have not been linked to a specific founder population yet; one current guess is that those colours may be associated with Crabbet/Old English horses. Then there’s the section with the purple bar and asterisk beneath it, showing noticeable amounts of Thoroughbred blue: those are all racing “Arabians”, surprise surprise. 

But really, the big takeaways for me would be that the Straight Egyptians are more vulnerable than I realised, and that Arabian breeders outside the cradle countries need to make more use of AI to incorporate genetics from the desertbred horses. Maintaining the breed’s unique and marvellous levels of diversity is important for the long-term health and survival of the breed. Also that we can actually have our horses’ genomes tested now, which is incredibly exciting, and such a powerful tool for breeding, for welfare, for management. 

References 

Almarzook et al.. 2017. ‘Genetic diversity of Syrian Arabian horses’. Animal Genetics 48:486-489

Cosgrove et al.. 2020. ‘Genome Diversity and the Origin of the Arabian Horse’. Scientific Reports 10:9702 

Khanshour et al.. 2013. ‘Microsatellite Analysis of Genetic Diversity and Population Structure of Arabian Horse Populations’. Journal of Heredity 104:386–398

[equine-science]

Horses pass with flying colors the experimental tests of: their excellent memory; their ability to learn through instrumental conditioning (sometimes rapidly); their ability to discriminate; their powers of stimulus generalization; and how one learning experience can enhance their uptake of another. However, empirical evidence suggests that they have little or no capacity for reasoning or insight. From an anatomical perspective, Bermond uses the argument from analogy to propose that animals without well-developed prefrontal cortices (including horses) would be unable to perform the mental abilities (such as reasoning) conferred by such brain features. Furthermore, he contends that reasoning has a maladaptive downside in that it allows animals (i.e. humans) to project and prolong their worst fears, and develop psychotic behaviors. He states that the prolongation of the emotional feeling (in humans) is a well known phenomenon and psychological defence mechanisms such as displacement, projection and suppression are, for example, unlikely to occur in the absence of this process'. 

Throughout evolution, grazing animals have been on the menu for predators. Being aware of such a plight would be maladaptive in terms of stress and interrupted foraging if a horse were slow, young, ill, lame, in foal, fearful of darkness or had a foal at foot. But horses never required higher mental abilities such as reasoning because, as Budiansky points out, grass (unlike a mouse!) doesn't hide or require planning or ambush to catch it. 

Reasoning is an expensive luxury and is most likely not selected for by the grazing niche. Brain tissue is many times more expensive to fuel than other tissues and is subject to strong selective pressure. The impoverished grazing niche that the horse has evolved to exploit adds an extra imperative for neural efficiency. Moreover the lack of higher mental abilities is adaptive for grazers such as equids, because it allows the formation of repetitive behavior patterns such as escape routines. The advantage of these 'habits' over more reflective mental processes lies in their speed of acquisition, and the immediacy and stability of reactions.

Horse handlers frequently witness that horses have little or no insight into their own instinctive behavior. As humans we are astounded that an animal would maim or kill itself in the execution of pulling back from a tie-up post, thrash itself to bits in a trailer (float), or literally bolt towards solid obstacles, as is sometimes seen in cross-country phases of horse trials competition. The riders in the latter instance frequently believe that these horses are simply 'keen'. Another sign of horses' apparent lack of insight is that they have little concept of 'form'. For example, many horse people have noticed that some horses show tremendous fear when confronted by changes in form of objects or even in conspecifics. If such horses have never seen a small white pony, they seem unable to extrapolate that it is a horse. Similarly, some horses seem unable to interpret correctly the form of their closest relative, the donkey, and react as if it were a potential predator. In a further example, if a familiar human enters a field occupied by horses and drops to her hands and knees to move quadrupedally among them, they will reliably flee. This shows that they fail to work out how the familiar biped transforms into the unfamiliar quadruped. Importantly, we cannot be sure at this point that the horses flee because they are in fear of predation. A simpler explanation is that they are responding to an aversive stimulus without necessarily assuming that it could catch and consume them.

-  Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

By tailoring training strategies to the species' mental ability, we can increase the efficiency of training and minimize misunderstandings in human-animal interactions. For example, when humans have expectations that animals 'understand' what is required, they often give inappropriate signals to the animals (such as delayed, inconsistent or meaningless reinforcements) that result in deleterious behavioral changes. Wiepkema indicates that unpredictability in the stimulus-response relationship causes conflict behaviors such as redirected and displacement behaviors. If these behaviors fail to satisfy the animal's current motivation, the animal may learn that it is unable to improve its well-being. Not surprisingly, learned helplessness has been identified in domestic horses. Classically, this takes the form of reduced responsiveness and the appearance of lethargy. In essence, the animal shows evidence of having given up any attempt to improve its welfare. For that reason, it is sometimes assigned the synonym learned hopeless ness. Although learned helplessness is a manifestation of compromised welfare, it is often referred to as 'staleness' in equestrian texts. Trainers are frequently at a loss to explain the origin of the seemingly 'naughty' or 'bad' behavior in their horses. Their dilemma arises from the fact that they believe the horse has a temperament problem or 'vice', rather than seeing that it has a training problem, an enlightened view that releases the horse from responsibility for the problem and puts it squarely at the feet of the trainer. In most cases, and with the exception of horses that are responding to a painful lesion, the fault indicates that the signals trained by pressure-release in the early training of the horse were either incompletely installed or have since deteriorated through lack of attention to their integrity.

Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

It should be acknowledged that, when trainers apply the principles of learning theory, they generally achieve desirable results. Throughout history, there have been riders who were adept at putting learning principles into practice, but who did not have the advantage of a theoretical basis. They were considered 'natural' horsemen. Biographies of gifted riders repeatedly suggest that they were ta loss to explain their talents. Unfortunately, this has led to the myth of horse whispering and the mistaken belief that training is more art than science. This set of beliefs has led to a consequent denial of the benefits of applying structured behavioral principles to horse training. Although the equine industry is steeped in tradition, its stakeholders have demonstrated that they can nonetheless take heed of new information, especially when it is demonstrated convincingly. The new global wave of horsemanship, as expounded by the 'horse whisperers' and 'new age' trainers, is slowly raising awareness of alternative ways to view the horse and approach horse training. By approaching the so-called 'problem horse' with a different set of tools, these trainers have provided some enlightening solutions to problems that have presented difficulties for traditional equestrian ideology.

Sometimes the horse-whispering myth provides an irresistible superhuman kudos to the practitioner. But perhaps the greatest limitation of many horse-whispering systems is that training practices are once again locked into method without the illuminations and extrapolations provided by learning theory. Their techniques have arisen from the historical trials of practical horsemanship. Furthermore, the paranormal mystique that sur rounds horse whispering and the tremendous variety of techniques tend to confound any search for a unifying principle. Thus horse whispering is often applied without the sort of paradigm shift in thinking about the cause of the problems that we have seen in the behavior modification of other domestic species such as dogs. For this reason much of the current wave of 'new age’ horse training remains within an anthropocentric and anthropomorphic framework. This is unfortunate because any assumption that the horse is motivated by anything other than its instinctual drives adds an unnecessary layer of complexity to its training. Anthropomorphic explanations of how compliant horses 'understand' and 'oblige' us are unhelpful for at least two reasons: first, they mystify the training process for novice riders, and second, they imply that non-compliant horses are some how malevolent. This explains why in one text of equine behavior modification, some horses have even been described as 'depraved'. Some practitioners convey an appealing message: that horse training is simply a matter of demonstrating leader ship or dominance in a manner analogous to that shown among horses to each other. Anthropocentric labeling of human-horse interactions makes the interpretations by some proponents of natural horsemanship sound irrefutably plausible and humane. Unfortunately, such labels can be misleading, contradictory and constitute potential barriers to effective training. They can also lead to misunderstanding, conflict and reduced welfare for human and equine participants. One of the potential dangers in adopting an anthropocentric framework to explain horse motivation is that the trainer/rider may assume that a horse knows what the human wants. This assumption permits humans to issue unclear cues, leading to frustration and perhaps even feelings of deception when these fail to pro duce the desired outcome in the horse. For example, some practitioners insist that horses in round pens signal to their human trainers as they would to high-ranking herdmates, and further that they are motivated to be with those humans simply because they 'respect' them. In contrast, it is possible that horses in roundpens are showing distance-reducing affiliative signals that are being misinterpreted. However, recent empirical studies suggest that the responses of horses to humans in confined areas, such as roundpens, are context specific and may rely more on negative reinforcement than on innate equine social strategies. These findings prompt scientists to question the interpretations of horse responses to roundpen interventions commonly offered by some practitioners and offer more scientific, measurable interpretations in horse handling and training.

Unfortunately, some of the 'modern' training systems are simply recycled in that they are just old horseman ship skills repackaged in a pseudo-scientific wrapper. Predictably, these systems do not always follow the principles of the psychology of training as clearly as they should. Some retain familiar pitfalls such as: multiple signals given concurrently; different responses for a single signal; lengthy delays in reinforcement.

Finally, a note about the increase in the popularity of roundpens that has resulted from the global interest in 'whispering' and relies on an understanding of the flight zone of an animal. A tame animal has a flight distance of zero. Animals are acutely aware of this zone of safety around them so that when it is breached, they move away. In a roundpen situation the horse stops moving when the trainer retreats from the flight zone. It seems that there is sometimes a perceived notion that creating an emotional crisis during roundpen training is actually desirable, probably because it forces the horse to offer a change in 'attitude' after which it accepts the human as 'leader'. The simplest explanation of this change is that the horse's running away in the roundpen does not increase the distance between it and the human, thus allowing the trainer to use actions and postures to reinforce slowing and shape the horse to approach. Similarly, the practice of lunging hyper-reactive horses before training can be seen as problematic as it is often little more than an opportunity for the horse to learn and practice flight-related behaviors. 

We must exercise caution before advocating approaches to equine training that involve chasing horses and causing them to associate fear responses with any human interactions, because we now know that fear responses and associations are not as prone to extinction as other learned responses. The horse may well learn to approach humans, but the means does not justify the end, because, if Le Doux's findings are to be given any credence, the experience of being chased can leave the horse with a more 'hair trigger' flight response. The danger is in the retention of flight-response associations, and its translocation to other interactions with humans. The implications for rider safety are profound.

-  Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

Modern behavioral psychology has established learning theory as the cornerstone of elegant training programs in many laboratory and performance species, but is only now beginning to become incorporated in any significant way into contemporary equine training or into the education of equestrian coaches. Because horse-training was well entrenched in its ways by the time Pavlov, Thorndike and Skinner came along, riders have not been altogether receptive to these scientists' findings.

The assumption that the horse is a willing partner and that the aim in coaching is largely to train the rider's biomechanics to merge into those of the horse is widely accepted in dressage circles. While it is not disputed that, after the consolidation of operant responses, this ideology plays some part in the later development of horse training, the overall approach neglects trial and-error learning (operant conditioning). Problems arise when equestrian methodologies focus on classical conditioning before or instead of the more deeply ingrained pressure-release responses through trial-and- error learning. This is because confusion (and therefore conflict) often arises in horses unless the basic responses have been installed thoroughly in the first place by trial-and-error learning through negative reinforcement. The fundamental trial-and-error responses under-saddle comprise stimulus control of acceleration and deceleration in gait, limb tempo and stride length, turns of the forequarters from each rein and turns of the hindquarters responses from the rider's legs. Training the horse by simple cue associations neither ensures controllability in all environmental contexts, nor provides the range of responses that is required for ultimate control in the Olympic equestrian disciplines of show-jumping, horse-trials or dressage. Furthermore, the randomness in behavioral response that horses are able to exhibit when not under complete handler/rider control results in inconsistent stimulus-response relationships which frequently cause chronic stress. It is assumed that the prevalence of such methodologies has arisen in the absence of a logical framework based on learning theory.

The cognitive revolution of the 1970s rejected behaviorism. Its legacy is the 'tendency to underestimate the power of Skinnerian conditioning to shape the behavioral competence of organisms into highly adaptive and discerning structures'. This probably contributed to the resistance to the understanding of learning theory in those domains within animal training where it had not already been accepted. Indeed, many texts on equine behavior seem to imply subjective mental experiences in horses. It would be a scientific error to assume the existence of abilities in the absence of data. Even if there are no data supporting the negative or affirmative case, assuming subjective mental experiences in animals would constitute an unacceptable rejection of the null hypothesis. Moreover, most of the published peer-reviewed data strongly indicate that horses lack insight into their instinctive behaviors. As we shall see in the discussion of equine mentality that follows, there are strong selective pressures for this lack of insight to occur.

- Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

There are welfare implications in failing to identify adequately the mental abilities of all animals in the care of humans. Overestimating an animal's mental ability must be seen as a major contemporary welfare issue when it manifests as abuse, wastage, stress and conflict behaviors.

As horse trainers and handlers, our understanding of the horse's mental abilities is based largely on a centuries-old tradition of horsemanship. Horse-training textbooks (including pony club texts) throughout the world take their reference from traditional horse practice or from the 'great masters' of horsemanship who lived in the past 500 years. Such texts generally abound with words to describe horse behavior that imply reasoning abilities. They generally assume that the horse 'understands' his training rather than simply responding through reinforcement. Training a horse within the traditional anthropomorphic framework has a number of potentially negative implications for horse welfare, as well as for the safety of riders and handlers. For example, if you believe that a horse complying with your commands is showing a willingness to please you, then you may also believe that when the same horse fails to comply he is actively seeking to displease, defy, undermine and even embarrass you. This belief system explains why so many riders feel justified in physically punishing horses for failure to perform. So while a coach may instruct a child to whip her pony as a punishment when it fails to jump a fence, an equitation scientist primarily sees the lack of response as evidence of pain or a training deficit. A scientific approach acknowledges that lack of forward movement over the fence is but one of myriad other responses that the pony failed to offer, and that whipping after the error is not going to help the pony identify the correct response in the future. We offer this specific example, not least because this issue of children whipping horses is emerging as an important topic in animal welfare debates that are being informed by equitation science.]

Furthermore, the anthropomorphic view of the horse is not supported by scientific examinations, which suggest that equids possess little or no higher mental abilities. Mindful of this, equine ethologists avoid interpreting responses as reflections of human emotions and values. They do not do this to demean horses but to recognize that there are often simpler and more plausible explanations for most of the horse's responses.

Training does not always go according to plan. Some horses are predisposed genetically to trial undesirable responses rather than desirable ones. Some horses learn to evade stimuli most effectively when the stimuli are predictable by association, e.g. in a school context. Horses that have been subjected: to inconsistent signals, such as the lack of release of pressure, or to the pain of bad schooling, often acquire the reputation of being difficult and are sold on to homes where more often than not the harshness of schooling is escalated. This contributes to disturbing slaughter statistics. For example, in a French study of more than 3000 non-racing horses, some 66.4% died aged between 2 and 7 years. Unlike data from the racing industry, this wastage was not attributed to orthopedic or respiratory disease but more likely to inappropriate behavior. The welfare implications of this wastage suggest that veterinarians and equine scientists should become well versed in learning theory since it is the basis of good training, continuing education and behavior modification. The wrong approach to training can have consequences far worse than simple time-wasting. 

The emotiveness in the horse-riding welfare debate has fostered empirical research into the ethics of equitation and an analysis of some of the more unorthodox interventions that arise during handling, training and competition. According to Derksen and Clayton, 'Knowledge of equitation science may help veterinarians play a more effective role in preventing injuries to horses and their trainers, and in recommending more effective methods of treating and retraining equine athletes when injuries do occur, thereby improving sport horse wellbeing.'

-  Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

The prevailing mindset throughout history has been to abandon, one way or the other, the less 'willing' equids because they have been regarded as having some moral (and even spiritual) involvement in the training proc ess so that they are assumed to have decided that they would not comply. These are the horses that, instead of learning what is required of them, learn to resist and escape and become the bolting, jibbing, balking, refusing, rearing, bucking and shying animals that are regularly described in books on so-called problem horses. These are the animals that change hands rapidly with the consequent addition of different commands and consequences that exacerbate the inconsistency of earlier training and increase the pressures that have caused the problem in the first place. Learning theory provides principles and guidelines for training. While these are usually adhered to by good trainers, they are not proposed as the first principles in contemporary horse-training literature. It seems strange that throughout the world, the language of learning the ory is almost never taught as a basic first principle in riding schools. We submit that these omissions precipitate confusion and therefore conflict in horses and ultimately contribute to welfare problems and wastage. Training is most rapid and consistent and training related stress is minimized when training practices exactly match an animal's mental abilities. This is evident in the results of great scientific animal trainers such as Marian Bailey, a student of Skinner, and those largely responsible for the tremendous advances in training cetaceans, pinnipeds and canids. The International Society of Equitation Science (ISES, www.equitationscience.com) has proposed eight principles as a means of identifying horse-training systems that align with what we know about learning theory as well as encouraging those who do not to employ them. The application of these principles is not restricted to any single method of horse-training, and ISES does not expect that just one system will emerge. There are many possible systems of optimal horse-training that adhere to all of these principles.

Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

Study: Bit-Related Lesions Found in 52% of Eventing Horses – The Horse

Finnish researchers found more horses with bit-related lesions than horses without—and most of the riders had no idea.

“If horse handlers would monitor the bit area themselves and notice when their horse had lesions, they could  improve their horse’s comfort and welfare,” said Kati Tuomola, DVM, of the Research Centre for Animal Welfare in the University of Helsinki’s Department of Production Animal Medicine, in Finland.

“By giving them a rest from the bit to give the lesions time to heal and paying attention to how they’re handling the horse—educating themselves and watching their rein tension—they could prevent the lesions from becoming chronic and (protect) the horse from further pain.”

Two years ago, Tuomola and her team noted that 84% of trot-racing horses on Finnish tracks had bit lesions after the race. While the statistics were better—at “only” 52%—in eventing horses, as her team reports in Frontiers in Veterinary Science, there’s still a lot of progress to make, she said.

“Bit-related lesions definitely hurt; there is no doubt about that,” she said. “The amount of pain is difficult to evaluate, but the mouth is intensely innervated.”

In her latest study, Tuomola investigated the mouths of 208 horses and ponies just after cross-country during seven national events and one international event in Finland. She and her assistant looked inside the horses’ mouths using only their gloved hands and a headlamp. They found that 109 horses—52%—had at least one fresh lesion, meaning it was new and probably just happened (but could have been developing for a while), she said. About 39% of the all the horses had bruising, and 19% had one or more open wounds. Lesions were mild in 22% of the horses, moderate in 26%, and severe in 4%. One horse had as many as five lesions in its mouth, she said.

Like in the trotter study, Tuomola found that mares were more likely to have moderate or severe lesions than geldings. “Different rein tensions might be behind this result,” she said. “Or it might be differences in how riders handle mares, how mares sense pain, levels of anxiousness or excitability, or wound healing. Whatever the cause, it’s very good to be aware of the fact that mares are at a higher risk, so we can be more mindful of that when working with them.”

Bits that were particularly thin or particularly thick were also associated with a greater risk for moderate to severe lesions. “This was a bit surprising, but in a way logical,” Tuomola said. Thick bits can push more on the mouth tissues, while smaller bits concentrate more force over a smaller surface, creating high pressure points, she explained.

Meanwhile, lesions of the bar (the bony gum area without teeth) were more common with unjointed bits, as her team also found in harness racing horses.

Interestingly, the scientists found no associations between the severity of lesions and the kind of noseband used, competition level, performance results, or the horse’s age, she said.

The new investigation has revealed that bit-related lesions were six times greater than what scientists previously found in eventing horses in Denmark. But because the competition organizers in the Danish study did not allow the researchers to open the horses’ mouths, they could only report on the lesions they could see from the outside, that team stated.

In the Finnish study, the riders—who all voluntarily presented their horses for checks—were often surprised to learn that their horses had bit-related lesions, said Tuomola. “Almost everyone wanted me to show them the lesions; they wanted to see them for themselves,” she said. “Some of the riders were surprised, and some were sad. I think that the majority of them thought that there wouldn’t be anything there.”

The findings underline the importance of recognizing that the way we ride and the bits we use can damage horses’ mouths and cause them pain, even if it doesn’t look like it from the outside, Tuomola said.

“A few of the riders in our study might have been aware of the outer lip commissure (cracking) lesions, because that’s the one place that some riders monitor,” she said. However, riders should also learn to open their horses’ mouths, pay attention to signs of injury, and understand how their bits are affecting their horses’ oral health and welfare in general.

Horses have certainly been dealing with bit-related pain for more than a century, said Tuomola. But ignoring the problem isn’t making it go away. “Bit-related lesions have been mentioned in newspaper texts and veterinary literature since at least around 1860-1890,” she said. “They’re definitely not new.”

Going forward, show organizers might encourage more welfare-friendly bit use by holding open-mouth checks rather than only looking outside the mouth, Tuomola suggested.

“It would be best if there were no lesions at all,” she said. “However, it would be a good idea to monitor the bit area at least from a few randomly drawn horses in competitions, because lesions usually don’t bleed outside the mouth. That way, they could at least prevent the horses with severe lesions from competing. This would show that mouth lesions are taken seriously in the horse industry.”

[equine-science]

It is appropriate here to challenge some of the central features of traditional equine educational dogma. In some sectors of horse-training, such as the sport of dressage, the cues and signals used to elicit alterations in the mobility and posture of horses are known as 'aids'. This word is antique in origin, derived from the French verb 'aider', meaning to help. The notion that cues in any way offer assistance to horses is anthropocentric and has been abandoned in our text because it nourishes the notion of the 'benevolent' horse, the horse that is a willing partner. Horse-trainers should respectfully recognize that training is an act of equine exploitation rather than equine enlightenment, and modern equitation must take full account of the cognitive processes of the horse. Despite empirical data that demonstrate the phenomenal memories of equids and the likelihood that horses do not need to be reminded how to execute their schooling tracks, trainers remain committed to regular schooling activities that usually comprise repetitive maneuvers involving 10-m circles, 20-m circles, serpentines and so on. If horses can indeed learn after a single trial only, it could be argued that these exercises are of more importance to riders than to horses. At the same time many riding tutors maintain that through such drilling the horse develops the musculature required to maintain self-carriage without having learned anything. This circumvention of the need for any understanding of learning theory is unfortunate because it contributes to the mystification of equestrian technique by denying the central role of negative reinforcement.

Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

Although the possibility of supplementary hormones generated by the adrenal gland has been raised, aggressive masculine behavior after castration is not usually dependent on hormones. These significant outliers in the distribution of sex-related responses demonstrate that the brains of male horses are masculinized before birth. Agonistic responses reinforced prior to castration may also contribute to some of the aggression seen in geldings. There is no evidence for the traditionally held belief that epididymal remnants ['proud cut'] perpetuate sexual responses after castration. Because castration of cryptorchids can be difficult, it is possible that some testicular tissue and therefore testosterone production can remain after surgery. Plasma estrogen concentrations are useful in discriminating between cryptorchids and geldings.

Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

As mammals, horses have brain characteristics that suggest their learning mechanisms may be similar to those of humans. Like humans, horses are proficient at trial-and-error learning (learning to perform a reaction through reward), classical conditioning (learning associations between events) and habituation (learning to ignore aversive stimuli that do not hurt). Beyond these basic mechanisms, horses can also generalize stimuli, and can even categorize objects based on similar physical characteristics. That said, cognitive research has yet to produce empirical evidence that horses can develop abstract concepts. Indeed, there is no peer-reviewed published evidence that horses possess significant higher mental abilities beyond generalizing and categorizing. Attributing human cognitive powers to horses is a double-edged sword. It may appear to honor horses' minds, but it inadvertently excuses violence in training since a horse that thinks as we do must surely know what we want it to do and can reason why it is being punished. Without downplaying the unique features of equine intelligence, scientists look for the most parsimonious explanations of phenomena. What horse people may regard as examples of reasoning in their horses usually turn out to be trial-and-error learning. The pony that fiddles with the gate latch and learns to open it is a typical example. It is clever, but it is not an example of reasoning.

Equine Behavior: A Guide for Veterinarians and Equine Scientists, Second Edition by Paul McGreevy

[equine-science]

Research shows the calming benefits of lavender aromatherapy for horses.

Research recently published in the Journal of Equine Veterinary Science found significant signs of stress reduction in horses that inhaled lavender from a diffuser. The study was conducted by Isabelle Chea, a then-undergraduate honors student at the UA, and Ann Baldwin, UA professor of physiology and psychology.

"Horses can be under a lot of stress, so I was interested in seeing if aromatherapy could help in reducing stress," said Chea, who had never been around horses before taking Baldwin's course, Physiology of Mind Body Interactions, at the UA in Tucson, Arizona.

During the class, Baldwin uses horses to teach students about heart rate and heart rate variability, which is a measure of the variation in time between each heartbeat. Both are indicators of the level of stress a person or animal is experiencing, though heart rate variability is a much more sensitive measurement.

Heart rate was the focus of a limited amount of prior research on the use of aromatherapy to calm horses in the presence of a stressor, such as trailering. In one study, horses were startled by an air horn and then provided with humidified lavender air. The horses' heart rates increased in response to the air horn but returned to normal more quickly in those that inhaled lavender.

None of the studies looked at a horse's response to aromatherapy in the absence of an imposed stressor, though, and none measured heart rate variability.

"We wanted to test regular horses that aren't stressed out by external forces," said Baldwin, who rides dressage on her 18-year-old quarter horse, Major. "Some horses and some breeds, it's just in their nature that they are more stressed. So, we wanted to use horses that were not being scared deliberately to see what effect, if any, the aromatherapy had on them."

Baldwin enlisted the help of other owners at her boarding stable to put together a group of nine dressage horses of varying breeds and ages. Each horse was led to a small paddock and held by a volunteer while a diffuser containing lavender essential oil was held near the horse's nose. A monitor tracked heart rates and heart rate variability for 21 minutes total -- seven minutes before the introduction of the diffuser, seven minutes with the diffuser in close proximity, and seven minutes after it was removed.

"The heart rate didn't change; what changed is what's called the parasympathetic component of heart rate variability," Baldwin explained. "One of the parameters of heart rate variability is RMSSD, and that represents parasympathetic input, which is the relaxation part of the autonomic nervous system. If RMSSD goes up, that indicates the horse is relaxed. We found that when the horses were sniffing the lavender, RMSSD significantly increased compared to baseline."

The data were supported by the horses' observed behavior, which often included relaxation signals such as neck lowering and licking and chewing while the lavender was being inhaled.

The experiment was repeated with water vapor and chamomile, neither of which produced a similar calming effect or increase in RMSSD.

"We did get a calming effect with the lavender, but when we measured afterward, we no longer had the effect," Baldwin said. "So, it's just during the sniffing of the lavender that we see this calming effect."

The research has direct implications for horsemen and horsewomen who may be looking for new or natural ways to calm an anxious or nervous horse. Traditional tranquilizers often have long-lasting effects, while lavender can be used precisely and exactly when needed.

"Some horses don't like to be shod. So, when the farrier comes and starts banging around with their hooves, it would be good for that," Baldwin said, giving a practical example of how lavender aromatherapy could be used in the barn. "You don't need a diffuser, really. Just put a few drops of lavender essential oil on your hand and let your horse sniff."

Baldwin says future research projects could examine the effectiveness of aromatherapy for horses using other scents or doses. When it comes to lavender, though, the research is clear. A sniff is all it takes to calm an anxious equine.

[equine-science]

Training Aids: How Their Fit Could Help or Hinder Longeing Horses – The Horse

Researchers know that, when used and fit properly, training aids can positively affect horses. However, improperly fitted equipment could squelch any benefits these systems offer.

Researchers know that, when used and fit properly, training aids, such as the Pessoa training aid, can be useful in longed horses and have positive effects. However, British researchers have confirmed that pressure from some training aids could prevent horses from improving their movement through these aids.

“Training aids are very useful for a variety of reasons, but the benefits of their use might be diluted when there are other pressures interfering,” said Russell Guire, a PhD candidate at the Royal Veterinary College, in London, and a researcher at Centaur Biomechanics in Warwickshire, both in the U.K. He presented his group’s study at the 2017 British Equine Veterinary Association Congress, held Sept. 13-16, in Liverpool.

In their study, Guire and his fellow researchers tested three training aids’ effects on 10 healthy, sound riding horses’ movement during longing. A single longer worked each horse in both directions, with four repetitions, each time fitted with either a surcingle (also called a training roller in the U.K.) alone or a training roller with a Pessoa system, a continual rope system, or side reins. The scientists equipped the horses with inertial measuring units to determine pelvic range of motion and movement symmetry during the tests.

Although the researchers found minor differences between the training aids compared to the training roller alone, there were no statistically significant differences in the studied movements at both trot and canter, Guire said.

So what does that mean for these aids’ use?

While science has already confirmed the usefulness of training aids like the Pessoa system and elastic bands, improperly fitted training rollers could be squelching any benefit these systems offer.

“We’ve noted significant pressure under the training roller that’s close to the pressure found during a sitting trot,” Guire said. “Most rollers don’t have trees, so when they’re tightened up, they put that pressure directly onto the horse’s spine at about the level of T12-T13 (thoracic vertebrae). We believe that this pressure could reduce any benefits the horse could have from the training aids.”

Previous studies by the same team have already indicated that pressure at T12-T13 inhibits locomotion, he added.

Their group is currently working on a study that should help give concrete recommendations about how to fit a training roller so as to let horses fully benefit from training aids on the longe, said Guire.

In the meantime, however, people can try longing with a training roller on top of the saddle or putting pads around the withers to ensure clearance under the training roller, he said.

The study, “Effect of Training Aids on Movement Symmetry, Pelvic Range of Motion and Rein Tension Pressures During Lunge Exercise,” was published in the Equine Veterinary Journal.

[equine-science]

Bit, Noseband, Spur, and Whip Lesions in Competition Horses Studied – The Horse

Most equestrians would be horrified to know they’re hurting their horses. But with the equipment we use—from spurs to nosebands—we might be unintentionally causing them harm.

Bits and Nosebands

Clayton said 9% of all horses had lesions or blood at the corners of the lips, and lip lesions were more prevalent at higher levels of competition. The prevalence of lesions differed between sports:

Horses: dressage 10%, show jumping 8%, eventing 7%, and endurance 5%

Ponies: dressage 16%, show jumping 5%, eventing 3%, and endurance 12%

Surprisingly, Clayton said, the researchers found no difference in oral lesion incidence between bitted and bitless bridles; therefore, using a bitless bridle did not protect against the development of oral lesions, she said. She also noted that bit type did not affect lip lesion prevalence.

With nosebands, “tightness of the upper (cavesson) noseband strap was more important than tightness of the lower noseband strap (drop, flash, lower strap of a figure-eight, or Micklem),” Clayton said. “Tight upper nosebands were associated with more lesions at the corners of the lips than looser nosebands. The results support the likely detrimental effects of tight cavesson nosebands and suggest that noseband tightness is related to the presence of lesions and blood at the corners of the lips.”

Clayton advised riders to bear this in mind when adjusting tack: “The upper noseband strap should allow a little laxity so that it acts by negative reinforcement. This means that if the horse opens his mouth, the noseband applies pressure to the face. When the horse closes his mouth, the pressure is immediately relieved. When the noseband is overtightened, it applies pressure continuously. Tight nosebands are more likely to be associated with lesions and/or blood at the corners of the lips and so are more likely to result in elimination under the blood rule.”

As with bitless bridles, forgoing nosebands also had unexpected results, she said. “Horses that did not wear a noseband had significantly more lesions at the corners of the lips than horses that wore a loosely adjusted noseband,” Clayton said. “Therefore, removing the noseband completely did not protect horses against developing lesions at the corners of the lips. There is sometimes a tendency to think that less is more. This study did not support the idea that riding bitless or without a noseband was better or kinder to the horse in terms of reducing the prevalence of lesions/blood at the corners of the lips.”

Whip and Spur Use

Regarding deleterious effects, the researchers found that:

Overall, 77% of riders used spurs, 3% of horses had worn hair on the ribcage, and <1% had blood on the ribcage;

There was no difference in lesion prevalence between clipped and unclipped horses;

There was no difference between sports when it came to the presence of worn hair or blood associated with spur use;

Roller-ball wheel and hammer-style knob spurs were significantly more likely to be associated with hair on the spur;

Spur length and competition level were associated with the likelihood of finding hair loss or blood associated with spur use. A 1-centimeter prolongation of the spur length doubled the likelihood of finding worn hair on the horse’s ribcage. Additionally, when the competition level increased by one level, the likelihood of finding hair on the spurs decreased by 20%; and

Seven horses (two show jumpers and five dressage horses) had skin lesions apparently related to whip use.

“Based on the findings of the study, I would recommend that spurs should only be used by experienced riders who have good control of their leg position and use of the leg aids,” Clayton said. “Spurs should be only as long as necessary, and excessively long spurs should be avoided because they are associated with more lesions and are more likely to lead to bleeding.”

Final Remarks

“This is the first large-scale study documenting equipment use in competition and showing associations between the type of equipment and the way it’s adjusted with the presence of visible lesions that are likely related to using the equipment,” said Clayton. “It gives some guidance regarding types of equipment that are more likely to be detrimental to the health and comfort of the horse and offers guidance as to adjustments that may be beneficial or detrimental to the horse.

However, the fact that the study was performed during competition limited the scope of the examination. Different methodologies will be needed to explore further the direct associations between equipment and lesions.”

This study, “Lesions associated with the use of bits, nosebands, spurs and whips in Danish competition horses,” was published in Equine Veterinary Journal.

[thescienceofequus]

Equine ‘Sex Stereotypes’ Could Impair Horse Welfare – The Horse

Researchers said many equestrians' “preconceived ideas” about behaviors they associate with mares, stallions, and geldings could have serious consequences for training and welfare.

TheHorse.com | 3 June, 2018

Your 13-year-old neighbor, an energetic girl with six years of riding experience, asks your advice before buying her first horse. What do you recommend: a mare, a gelding, or a stallion? And why?

If you showed a preference for any of those three choices for your young neighbor, it’s possible that you’ve been influenced by a culture of sex stereotypes in horses. Australian and British researchers say many people involved in the horse industry have “preconceived ideas” about behaviors they specifically associate with sex, and such stereotyping could have serious consequences for training and welfare.

“This could have profound implications because horses regarded as difficult, dangerous, or bossy are likely to be treated differently from those regarded as calm, reliable, and easygoing,” said Kate Fenner, BEqSci Hons, of Kandoo Equine, in Towrang, Australia.

Furthermore, riders and trainers might assume that a horse’s unwanted behavior is simply a result of the horse’s sex, rather than reflective of an actual problem, such as pain or confusion, she said. As such, the horse might not receive the attention needed (specific training, veterinary care, etc.) to resolve the issue.

Fenner and her fellow researchers investigated people’s stereotypes about the sex of riding horses by conducting an online survey. They asked the 1,233 respondents to consider a family of four people—a man, a woman, a boy, and a girl—all of equivalent riding skill. The survey respondents chose the horses they considered appropriate for each family member among a mare, a gelding, and a stallion with equivalent levels of good training. They also addressed a series of questions about their reasons for their choices and the importance of certain criteria.

Fenner developed her online survey and conducted the study under the guidance of Paul McGreevy, BVSc, PhD, MRCVS, MACVS (Animal Welfare), professor of animal behavior and animal welfare science at the University of Sydney. She presented her results at the 2017 International Society for Equitation Science conference, held Nov. 22-26 in Wagga Wagga, Australia.

The scientists found that survey respondents were 2.5 times more likely to allocate a gelding to the girl than to the boy, Fenner said. And, in fact, more than 50% of the respondents didn’t allocate any horse to the boy. They also had a much stronger tendency to give a stallion to the man. Paradoxically, the respondents generally ranked rider sex as the least important factor in their decision-making, she said.

Meanwhile, they tended to attribute positive characteristics to geldings—calm, trainable, reliable, predictable. For mares, 74% of the people considered them “bossy,” while 93% labeled them “trainable,” “safe,” “willing,” and having a “good attitude.” Regarding stallions, 82% of respondents said they were “difficult,” and 80% said they were “bossy,” but at the same time, 95% said they were “trainable,” and 80% said they had a “good attitude.”

“These results show not only preconceived ideas about the sex of a horse but also contradictory logic,” Fenner said. “Should these results be of concern? I’d say yes.”