Monitoring signs of laminitis

A new scoring method has been shown to be useful for monitoring the progress of cases of endocrinopathic-laminitis. Endocrinopathic-laminitis or hyperinsulinaemia-associated laminitis (HAL) is a common form of the condition, typically encountered in overweight animals.
Being able to grade the severity of the signs is useful, both for assessing the response to treatment in clinical situations, but also for assessing potential new treatments when they become available.
 
The 4-point Obel scale has been used for many years to describe the severity of laminitic signs. (See below). It was devised for use with severe cases caused by sepsis or starch overload, and may not be as well suited to cases of HAL, which often show a more gradual onset. 
 

A new method was developed by Meier and colleagues (See below), which examines five key clinical signs: weight shifting, response to lifting a foot, gait at the walk and turning in a circle, and palpation of the digital pulse.

 

The value of this new method was investigated in a randomised controlled field study involving eighty horses and ponies with naturally occurring HAL, seen at 16 veterinary practices in Germany.

Independent veterinarians assessed the severity of laminitis using both the traditional Obel method and the Meier method. Assessments were made on the day of diagnosis then 4, 9, 14, 25 and 42 days later. Pain medications were withheld for 24 h before clinical examination in all cases.

 

The researchers found that the time taken for the laminitis to improve varied between individuals, and was difficult to monitor accurately using the Obel method. The Meier method could identify more subtle changes. They noted that there was considerable variation in the rate of improvement of individual clinical signs. For example, lameness when turning in a circle persisted longer than signs of weight shifting and reluctance to allow the front leg to be lifted.

 

A full, open access, report of the work is published in the journal BMC Veterinary Research. The authors conclude that the Meier method provides a reliable and consistent method for monitoring the clinical status of horses with HAL.

 

They suggest that the pattern of improvement described in their study should provide a useful benchmark against which individual cases and new treatments can be assessed.

 

 

Table 1 The Obel method of laminitis diagnosis and severity grading (Obel, 1948)

Laminitis grade	Grade description
Normal	Horse appears sound
Obel grade 1	At rest, the horse shifts its weight between the forelimbs; the horse is sound at the walk, but the gait is stilted at the trot in a straight line and on turning
Obel grade 2	The gait is stilted at the walk and the horse turns with great difficulty, but one forelimb can be lifted
Obel grade 3	The horse is reluctant to walk and one forelimb can only be lifted with great difficulty
Obel grade 4	The horse will only move if forced to

 

 Table 2 The ‘modified Obel’ or ‘Meier’ method of laminitis diagnosis and severity scoring

Order of examination	Criteria	Description	Points	Given Points
Stage 1
Examine horse standing	Weight shifting	No weight shifting	0
		Weight shifting – including shifting weight between all feet;	2
		Abnormal time spent lying down; placing forelimbs in front of body
Gently lift each foot up and put back down straight away	Forelimb lift	Prompt and willingly maintained (each forelimb)	0
		Reluctant and maintained with difficulty (each forelimb)	1
		Unable to lift foot/resists attempts to lift foot (each forelimb)	2
Stage 2
Conduct on hard surface Walk horse approx. 30 m side-on to examiner	Gait at walk	Normal gait	0
		Mild - short, stilted gait - still moves willingly	1
		Moderate - short, stilted gait - reluctant/difficult to walk	2
		Severe difficulty walking or unable to walk*	6
		*do not force horse to walk; skip gait at circle and continue with digital pulse
Turn on a short lead clockwise and anti-clockwise	Gait at circle	Normal circling	0
		Mild head rise, difficulty when turning, still moves willingly	1
		Moderate, sharp head rise, reluctance/difficulty turning	2
		Severe difficulty turning, slow and clearly painful	3
Stage 3
All feet must be square on ground	Forelimb digital pulse	Normal - able to palpate, normal magnitude but not bounding	0
		Increased magnitude or bounding digital pulse (each forelimb)	2
			Total Score

 

 Both tables from: The application of a new laminitis scoring method to model the rate and pattern of improvement from equine endocrinopathic laminitis in a clinical setting ( http://creativecommons.org/licenses/by/4.0/)

For more details, see:

 

The application of a new laminitis scoring method to model the rate and pattern of improvement from equine endocrinopathic laminitis in a clinical setting. 

Meier, A., McGree, J., Klee, R. et al. (2021)

BMC Vet Res 17, 16 

https://doi.org/10.1186/s12917-020-02715-7

"RoboGut" to study horse's gut microbiome

 

There is increasing interest in the gut microbiome, the mixture of bacteria and microorganisms living in the horse’s gut, and its relationship to health and disease.

Horses rely on microbes in the hind-gut to ferment the roughage in their diet, and break it down into nutrients they can absorb.

 

Disruption of the normal balance, for example by the overgrowth of a particular population of bacteria, may affect the normal healthy functioning of the horse’s gastrointestinal tract, and may result in disease.

 

Changes in the microbiome may lead to diseases affecting the gastro-intestinal tract – such as colic or colitis – and even conditions with more wide-reaching effects such as laminitis.

Researchers at Ontario Veterinary College (OVC), University of Guelph have developed a mechanical replica of the equine digestive system, known as “RoboGut”, which will to help them to understand the composition of a healthy horse’s gut microbiome.

 

Dr. Luis Arroyo, professor in the Department of Clinical Studies at the OVC, uses the horse robo-gut to understand how various food compounds are digested.

 

“The robo-gut offers us ways to understand mechanism of disease and potential treatment options for our patients, as well as helping us learn more about early detection and prevention of GI diseases,” says Arroyo. 

 

The researchers can alter the humidity and temperature to simulate the environment within the horse’s gut. 

 

“Through this manipulation, we can encourage a horse gut microbiome to thrive in the robo-gut,” says Arroyo. "Native microbiota play an important role in the digestion, absorption and fermentation of nutrients to maintain a healthy state."

 

“A healthy gut microbiome is essential for the proper systemic functioning of the horse’s entire body,” says Arroyo. “By looking at horse health holistically, we are able to prevent local and systemic ailments from flourishing.”

 

For more details, see:

 

https://ovc.uoguelph.ca/news/equine-robo-gut-helps-ovc-researchers-study-gastrointestinal-diseases-horses

Free Equine Webinar Series: Taking Science to the Stable

A free equine webinar series from the University of Guelph will run every two weeks until August 18. 

The talks aim to provide informative and insightful knowledge from experienced industry professionals.

Topics include:

 

• What’s Next? How to restart your business after a shutdown – Panel Presentation, June 30 at 7 p.m. EST 
• Foal Management and Nutrition of Newborn, Suckling, Growing and Orphan Foals – Don Kapper, July 14 at 7 p.m. EST  
• Routine equine handling using low stress and cooperative care techniques – Dr. Robin Foster , July 28 at 7 p.m. EST 
• Performance Nutrition – Feeding and Management of the Performance Horse – Don Kapper, August 4 at 7 p.m. EST 
• Turning Science into Stories for Horse Owners – Emily Esterson, August 18 at 7 p.m. EST

Registration is free but closes at noon the day before the event to ensure participants receive the Zoom link for the webinar on time. 

 

For more details, see:  uoguel.ph/equine-science-webinars

Value of strip grazing (and chance to win a strip grazing kit)

 Strip grazing can play a useful part in controlling horses’ weight a recent study has shown.

Strip grazing refers to reducing the amount of grass available by sectioning off a smaller area of the paddock using electric fencing. The fence is moved daily to provide gradual access to fresh grazing. A back fence may also be used which can be moved by the same amount to keep the overall grazing area the same size.

 

Restricting grass intake is an essential part of many weight management programmes, and the latest research on strip grazing shows that it can be an effective solution. For many horses and ponies, grass is the main source of calories in the diet and is also one of the hardest for owners to control. A 250kg pony living out at grass may consume enough energy (calories) to fuel a 500kg racehorse – equivalent to more than half a bag of conditioning cubes every day.

 

The study, comparing three restricted grazing practices for equine bodyweight management during the United Kingdom grass growing season, was conducted by Annette Longland in collaboration with SPILLERS via the WALTHAM Equine Studies Group.

 

Three groups of four ponies were turned out into individual paddocks that had been measured at the start of the study to provide 1.5% of the ponies’ bodyweight (dry matter) in grass, for 28 days. 

 

The ponies were assigned to one of three grazing practices: 

·       after a two-day adaptation period ponies were given access to the whole paddock with no restrictions; 

·       a lead fence was placed across the width of the paddock and after a two-day adaptation period, it was moved 1/26th of the remaining paddock length daily to allow access to fresh grass; 

·       after a two-day adaptation period a lead fence and a ‘back fence’ were moved by 1/26th of the remaining length every day.

 

Ponies with access to the whole paddock showed a significant increase in body condition score, but ponies in either of the strip grazed groups did not. The strip grazed ponies gained significantly less weight than ponies in the total allowance group, regardless of whether a back fence was used. In fact, strip grazing without a back fence was no less effective than strip grazing with a back fence, even though the grazing area got larger every day.

 

The WALTHAM Equine Studies Group, who provide the science behind the SPILLERS brand, have now published 100 research papers relating to obesity, laminitis, equine metabolic syndrome (EMS) and weight management. To celebrate, SPILLERS is giving one lucky horse owner the chance to win a strip grazing kit, including energiser, fencing tape and posts. The competition is running on the SPILLERS Facebook page from 21-28 June.

 

 

For more details, see:

 

Longland, AC, Barfoot, C, Harris, PA. 

Strip-grazing: Reduces pony dry matter intakes and changes in bodyweight and morphometrics. 

Equine Vet J. 2021; 00: 1– 8.

https://doi.org/10.1111/evj.13416

 

Investigating anaesthetic safety

 Despite improvements in anaesthetic techniques, there is still a significant risk of a horse dying under anaesthetic.

In 2002, the Confidential Enquiry into Perioperative Equine Fatalities (CEPEF), found the risk of death in horses (up to 7 days after anaesthesia) to be about 1 in 100, higher than in dogs and cats (about 1 in 1000). The perioperative mortality rate in man, for comparison, is one in ten thousand.

 

Anaesthetic drugs and procedures have advanced since then, but have they increased the outcome/ reduced the risk of perioperative mortality?

 

A new study of anaesthesia related fatalities in horses (CEPEF4) is now underway. 

 

The study will collect data from cases of general anaesthetic procedures, or standing sedation lasting longer than 15 minutes, in horses and donkeys from around the world.

 

So far, 70 clinics around the world have contributed information from 9000 cases, mostly from Belgium, United Kingdom, Australia, Ireland, France, Switzerland and Spain.

 

The prospective study aims to evaluate perioperative fatality rate and identify factors that increase or reduce the risk of mortality.

 

The project was presented to the Association of Veterinary Anaesthesiologists meeting in Dublin, 2020. A video of the presentation is available:

https://www.youtube.com/watch?v=Gg0tvW0UR24&t=183s

New equine rotavirus implicated in foal diarrhoea

Researchers at the University of Kentucky’s Maxwell H. Gluck Equine Research Center and the Veterinary Diagnostic Laboratory have made a preliminary identification of a novel rotavirus associated with diarrhoea in very young foals.

Foals often develop diarrhoea in the first two weeks of life.  Many cases respond well to routine treatment but some may develop life-threatening dehydration within a matter of hours.

 

This year, some farms in Kentucky have reported an increased number of cases of diarrhoea in young foals. 

 

The new rotavirus, identified by the scientists at the University of Kentucky, could not be detected using current diagnostic tests for equine Rotavirus A and appears to be different to the virus strain used in the currently available commercial vaccine.

 

Further work is underway to better characterise the virus and determine its role in the current outbreak of diarrheal disease. Additional investigations are also underway at UK to identify other possible causes, and researchers are sending out an epidemiological survey to farms to better understand the outbreak.

 

A test for the virus is now available. "We have now developed a real-time PCR assay to detect this new equine rotavirus B in fecal specimens," noted Dr Craig Carter, Director of the Veterinary Diagnostic Laboratory.

 

Both the Gluck Center and the Veterinary Diagnostic Lab recommend strict biosecurity protocols as the best protection strategy at this time.

 

For more information, see:

 

 http://news.ca.uky.edu/article/uk-gluck-center-and-industry-leaders-responding-uptick-foal-diarrhea-cases.

Can an owner questionnaire help monitor arthritic pain in horses?

Osteoarthritis (OA) is a major cause of chronic pain in horses but is an underrecognized and undertreated condition. Though often associated with advanced age, it can also occur in young horses. In addition to being painful, OA can severely curtail a horse's athletic career, and impact the bond between horse and owner if the condition limits a horse's ability to be ridden. Controlling it often involves a combination of medication and management change and relies on the ability to monitor the response and make adjustments accordingly.

A new study is testing to see if a simple questionnaire can help horse owners recognize and monitor signs of chronic osteoarthritis (OA) pain in their horses – helping their equine charges get earlier, more effective treatment and improving their quality of life. 

Dr. Janny de Grauw, from Utrecht University in the Netherlands, and Diane Howard, PhD, MSc., Equine Science Master graduate from the University of Edinburgh, in the United Kingdom, are the recipients of a Donor-Inspired Study grant from the Morris Animal Foundation, funded by long-time supporter, Dr. Wendy Koch. Dr. Koch, a veterinarian, has closely followed equine behaviour and welfare research over the years and wanted to increase the amount of funding available for studies in these fields.

To effectively treat pain, caregivers and clinicians need a way of monitoring and quantifying the amount of discomfort felt. However, a survey of horse owners in the United Kingdom found that owners have limited ability to identify pain and disease in their horses, underlining the need for a simple way of helping people to recognize chronic pain in their equine companions.

“As veterinarians, we want to treat horses with painful and debilitating conditions like OA as effectively as possible,” said de Grauw. “How well we can manage their condition critically relies on recognition of subtle signs of (worsening) pain by owners and caregivers, who can then seek help.”\

Under Dr. de Grauw’s supervision, Howard developed the 15-item questionnaire based on changes in horse behaviour through interviews with owners of horses diagnosed with osteoarthritis. The questions cover posture, facial expressions, movement and behaviour.

She will validate the questionnaire by having 60 owners of horses with chronic OA pain and 20 owners of horses without OA complete it. The owners with OA horses will complete the questionnaire twice in two days while their horse’s pain does not fluctuate, to evaluate how robust and reproducible the scoring instrument is. 

The research team hopes the easy-to-use questionnaire will help horse owners recognize when their animals are in pain and contact a veterinarian for appropriate treatment. It also may help owners monitor treatment effectiveness and pain progression over time, and guide owners and veterinarians in making quality-of-life decisions. 

“Many horses may deal with pain that is not recognized, particularly in its early stages,” said Dr. Janet Patterson-Kane, Morris Animal Foundation Chief Scientific Officer. “Giving their caregivers effective tools for detection, monitoring and decision-making has the potential for significant animal welfare impact.”

For more details, see: 

https://www.morrisanimalfoundation.org/article/osteoarthritis-pain-in-horses-questionnaire?

Lehi horse not as ancient as first thought

 Excitement generated by the finding of a horse skeleton in Utah thought to date from the late ice age was misplaced according to a new study. 

The pony sized skeleton was discovered in Lehi, north central Utah in 2018. It was first thought to have lived about 16,000 years ago as it was found lying amongst geological deposits from the last ice age.

Now further work using radio-carbon dating has shown that the remains are in fact a lot younger - dating from about 300 years ago. 

However, the disappointment of discovering that the horse was not an ice age relic was tempered by the insights it revealed into the place of horses in native American life. The work is reported in the journal American Antiquity.

William Taylor, assistant professor of anthropology at the University of Colorado Boulder, was sceptical that this was an ice age fossil. Although ancient horses were common in north America during the Pleistocene, they went extinct around the same time as other larger mammals such as mammoths.

His suspicions were raised by the presence of fractures of the vertebrae –  injuries not commonly found in wild horses, but typical in those having been ridden without a frame saddle.

The horse also had evidence of severe arthritic changes in several limbs.

Dental examination revealed that the horse was about 12 years old when it died. Radiocarbon dating showed that it lived up to about 300 years ago.

DNA analysis revealed that the horse was female. This, in combination with the signs of arthritic damage, suggested that the horse was being kept alive for breeding purposes after she had outlived her use for transport.

Analysis of sequential samples of tooth enamel for carbon, oxygen, and strontium isotopes led the research team to deduce that the horse was raised and tended within the region where it was found.

Taylor, lead author of the study, suggests that the horse likely died sometime after 1680, before European settlers moved into the Salt Lake region during the mid-19^th century.

 

For more details, see:

Interdisciplinary Analysis of the Lehi Horse: Implications for Early Historic Horse Cultures of the North American West. 

Taylor, W., Hart, I., Jones, E., Brenner-Coltrain, J., Thompson Jobe, J., Britt, B., . . . Roberts, P. 

American Antiquity, (2021) 1-21.

https://doi.org/10.1017/aaq.2020.109

To see Dr Taylor's exhibit "Horses in the North American West",  part of the  University of Colorado Museum of Natural History, go to:

https://www.colorado.edu/cumuseum/horses-north-american-west

Keeping horses safe from heat and humidity

 With the Tokyo Olympics due to take place shortly during the Japanese Summer, the Equine Veterinary Journal has compiled a collection of relevant articles covering the health and welfare of horses competing in hot and humid conditions.

The special online collection "Preparing for Tokyo Olympics" contains 11 papers and is available to read free of charge. It highlights the ground-breaking research that followed the 1992 Barcelona Olympics.

 

“This is not the first time that extreme heat and humidity has challenged the viability of Equestrian events at the Olympic Games,” said Christopher Elliott, who is Guest Editor of the collection. “It is vital that we learn from the past to ensure the welfare of equine athletes in the future.” 

 

Topics covered are:

 

• Physiological, metabolic and biochemical responses of horses competing in the speed and endurance phase of a CCI**** 3‐day‐event
• Physiological responses to the endurance test of a 3‐day event during hot and cool weather
• Physiological responses of horses competing at a modified 1 Star 3‐day‐event
• Adaptations to daily exercise in hot and humid ambient conditions in trained Thoroughbred horses
• Sweating rate and sweat composition during exercise and recovery in ambient heat and humidity
• Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation
• Comparison between two post exercise cooling methods
• Contributions of equine exercise physiology research to the success of the 1996 Equestrian Olympic Games: a review
• An index of the environmental thermal load imposed on exercising horses and riders by hot weather conditions
• Use of the Wet Bulb Globe Temperature (WBGT) Index to quantify environmental heat loads during Three‐day‐event competitions
• Risk factors for exertional heat illness in Thoroughbred racehorses in flat races in Japan (2005–2016)

 

Professor Celia Marr, Editor of the EVJ, added: “Prevention is always better than cure: this special collection provides much excellent research and knowledge gained from previous events. We must ensure that we use it to best effect to keep the equine athletes competing in extreme climates in Tokyo this summer safe, cool, healthy and performing at their best.”

 

To read the articles, go to:

 

https://beva.onlinelibrary.wiley.com/hub/journal/20423306/homepage/sc_olympics

Assessing horses’ welfare by reading their minds

A horse’s brain waves can reflect their welfare state according to recent research.

Electrical activity in the brain varies with the state of arousal of the different parts of the brain and the electrical waves have been grouped into bands according to their frequency: eg delta (δ: 0−4 Hz), theta (θ: 4−8 Hz), alpha (α: 8–12 Hz), beta (β: 12–30 Hz) and gamma (γ: >30 Hz). 

 

Theta waves tend to predominate during calm and relaxed states, while an alert state tends to produce more gamma waves.

Mathilde Stomp and colleagues at the University of Rennes, France, devised a headband for horses, to record the resting electrical activity in the brain (EEG – electroencephalogram). Then, to see if there was an association with the horses’ welfare state, they compared the patterns of electrical activity with an assessment of the horses’ behaviour.

Eighteen horses involved in the study were maintained under either “restricted” conditions (living in riding school stables with a few hours daily turnout on pasture and regular work) and “leisure” (on pasture all year round, with occasional leisure riding.)

The researchers found that theta waves tended to predominate in both sides of the brain in horses in a more positive welfare state, whereas beta waves tended to predominate in horses showing signs  of compromised welfare. Horses in a good welfare state produced fewer gamma waves in the right side of the brain.

A full report of the work is published in Applied Animal Behaviour Science. The authors suggest that “bilateral and left hemisphere theta activity is a promising neurophysiological marker of good welfare in horses, while a bilateral or RH [right hemisphere] high production of gamma waves should alert about potential welfare alterations.”

For more details, see:

Brain activity reflects (chronic) welfare state: Evidence from individual electroencephalography profiles in an animal model.

M. Stomp, S. d’Ingeo, S. Henry, H. Cousillas, M. Hausberger.

Applied Animal Behaviour Science, (2021) vol 236, 105271.

https://doi.org/10.1016/j.applanim.2021.105271

Atypical myopathy toxins found in mare's milk

 Research shows that the toxins responsible for Atypical Myopathy can pass to the mare’s milk. This can present a potential risk to the foal and may have human health implications in places where mare’s milk is drunk in preference to cow’s milk.

A case of atypical myopathy was identified in a mare and newborn foal in Germany. The mare had been grazing pasture close to Acer pseudoplatanus trees (sycamore or sycamore maple).

 

Johannes Sander and co-workers in Hannover, investigated the case.  A report of the work is published in the Journal of Veterinary Internal Medicine.

 

The authors analysed a sample of the mare's milk for hypoglycin A, the main toxin responsible for atypical myopathy, and other metabolites.

 

They also examined samples of commercially available frozen mare’s milk (for human consumption) from six different suppliers across Germany.

 

The researchers found low levels hypoglycin A and significant levels of metabolites (methylenecyclopropylformyl glycine and carnitine)in the milk from the affected mare. High levels of acylcarnitines, (indicators of the metabolic damage caused by atypical myopathy), were also found. The authors point out that the milk sample was collected two days after the mare had been removed from the contaminated pasture, and suggest that the levels of metabolites in the sample indicate that hypoglycine A levels would likely have been higher at the time the foal was nursing. 

 

Methylenecyclopropylformyl glycine and carnitine were also detected in one of the six samples of commercial mares’ milk.

 

The authors conclude that maple toxins can pass through mare's milk.

 

They also warn that their findings have relevance in human health. Seeds and unripe fruit of plants such as ackee and lychee contain similar toxins, and may present a risk to breast fed children.

 

 

For more details, see: 

 

Detection of maple toxins in mare's milk

Johannes Sander, Michael Terhardt, Nils Janzen 

Vet Intern Med (2021) 606-609.

 doi: 10.1111/jvim.16004

Does not getting enough sleep affect horses’ memory?

A recent study examined the effect of environmental factors on equine sleep stages, and whether this would influence cognitive performance during a memory task.

As a prey species, horses have evolved to cope with short periods of rapid eye movement (REM) sleep and are known for their ability to sleep, or at least doze, (Non-REM sleep, NREM) while standing up. They still have to lie down for REM sleep which is only possible during recumbency due to the lack of muscle tone that occurs during this sleep phase. 

 

In research conducted at Aberystwyth University, Linda Greening and others investigated the effect of two different light regimes, and two different depths of straw bedding on sleep patterns in horses. They also looked at whether the differences affected the horses’ response to a memory test – basically remembering which of four buckets placed around an arena contained a feed reward.     

 

In a report in Applied Animal Behaviour Science, the authors describe how ten adult riding school horses were randomly assigned to two equal-sized groups for the five-week experiment. Each group experienced a combination of one of two light conditions (lights on or off overnight), and one of two bedding depth treatments (straw bed 15 cm or 5cm deep) for six days.

 

 The authors found that the duration of sleep stages was affected by both the depth of bedding and lighting conditions. Under sub-optimal conditions, horses tended to spend significantly less time recumbent for both NREM and REM sleep. This was compensated for by increased time in standing NREM sleep.

 

Sub-optimal lighting and bedding conditions did not have a significant effect on performance during the spatial memory test. The authors suggest that, “a more cognitively demanding task may be required to differentiate the performance-related consequences of different levels of sleep duration and quality.”

 

 

For more details see:

 

The effect of altering routine husbandry factors on sleep duration and memory consolidation in the horse

Linda Greening, Josh Downing, Daniella Amiouny, Line Lekang, Sebastian McBride

Applied Animal Behaviour Science

Volume 236, March 2021, 105229

https://doi.org/10.1016/j.applanim.2021.105229

Irish sport horse survey

 Irish horse owners of all levels and disciplines are invited to take part in a survey to help research sport horse health.

Sinead Devine, Assistant Professor in Equine Clinical Studies at UCD School of Veterinary Medicine is currently undertaking a PhD on Sport Horse Health in Ireland. 

Her interest in Sport horse health comes from over 20 years working as an equine vet in Ireland and the US. She is also a 3* FEI Veterinary Delegate for showjumping, eventing & reining, and 2*endurance.

Horse owners of all levels and disciplines are encouraged to take part in the survey. The results will help direct further research for the Irish Equine Industry. Survey questions will include common disease conditions and their impact. 

The survey should take less than 10 minutes to complete. Responses are anonymous and participants will not be identified by their responses. 

For more details, and to take part in the survey go to:

http://bit.ly/horseownersurvey

Can horses smell human fear?

Research from Poland suggests horses can smell human fear.

 

Agnieszka Sabiniewicza and co-workers at the Institute of Psychology, University of Wrocław, looked at whether body odours collected from humans in a state of fear or of happiness produced different behavioural responses in horses that were exposed to them.

 

The research team collected body odour samples from ten fearful or happy humans. They achieved this by showing them a fear-inducing horror video or a cartoon.

 

Prior to viewing the films, the human subjects washed in perfume-free detergent and had avoided smoking, alcohol, odorous food, or hard exercise for a couple of days. While watching the films the “odour donors” had sterile pads in their armpits. The pads were subsequently collected and frozen.

 

Twenty-one adult Thoroughbred and Arabian horses took part in the study. Their response to the smell of fear, or happiness, or a control (no odour) was recorded. 

 

Two people, one known to the horse, the other unknown, stood quietly in different corners of the stable. They made no attempt to interact with the horse. The investigators then presented the horse with a pole to which odour pads were attached (pads from four fearful or four happy people were combined to reduce the risk of individual variation between odour donors) and recorded the horse’s response.

 

The researchers found that horses showed different behaviours in response to odours from fearful or happy humans.

 

Horses lifted their heads significantly more frequently and for longer in response to the fear odour and the control, compared to the happiness odour. 

 

Also, when exposed to the fear odour, there was a tendency for horses to touch, more frequently and for longer, a familiar person that was present during the test, than they did when exposed to the happiness odour.

 

The researchers conclude that, using human body odour as the only source of information about a human’s emotion is enough to induce some differential behaviour in horses. 

 

For more details, see:

Olfactory-based interspecific recognition of human emotions: Horses (Equus ferus caballus) can recognize fear and happiness body odour from humans (Homo sapiens)

Agnieszka Sabiniewicza, Karolina Tarnowska, Robert Świątek, Piotr Sorokowski, Matthias Laska

Applied Animal Behaviour Science (2020) vol 230; 105072

https://doi.org/10.1016/j.applanim.2020.105072

Does oxytocin influence friendliness in horses?

 Recent research suggests docility and friendliness in Thoroughbred horses might be related to blood oxytocin concentration.

Oxytocin, vasopressin (AVP) and serotonin are hormones and neurotransmitters that play a role in shaping social behaviours, such as aggression and social recognition.

 

In a study performed at Sangju International Equestrian Center, Geumhui Lee and Minjung Yoon measured the levels of the three hormones in the blood of a varied group of adult horses. 

 

They assessed the influence of breed, sex, and age on the concentration of each hormone. They also looked to see if there was any relationship between their concentration and docility and friendliness of the horses.  A report of the work is published in the journal Domestic Animal Endocrinology.

 

The authors report that oxytocin and vasopressin concentrations did not vary with the breed, sex, or age of the horse. But they did find that serotonin concentration varied with the breed and age of the horse. 

 

There was no correlation between docility and friendliness of the horses and either AVP or serotonin concentrations. However, the researchers did find a trend towards a correlation between docility and oxytocin in Thoroughbred horses.

 

They conclude that oxytocin concentration may be related to docility and friendship in Thoroughbred horses.

 

For more details, see:

 

Association of plasma concentrations of oxytocin, vasopressin, and serotonin with docility and friendliness of horses

Geumhui Lee, Minjung Yoon

Domest Anim Endocrinol (2021) 74:106482.

 doi: 10.1016/j.domaniend.2020.106482

 

Genetic risk of fracture in Thoroughbreds

Scientists at the Royal Veterinary College (RVC) have received funding for a study into the genetic risk of fractures in Thoroughbred racehorses.

The research paves the way for greater understanding of how best to identify and manage horses at high risk of such fractures and contribute to greater health and welfare of Thoroughbreds.

It is possible to monitor horses using diagnostic imaging techniques (such as radiography and CT scan) to identify changes in bones that could lead to fractures. However, such techniques are too expensive for routine use. This new research could potentially allow veterinary professionals to identify genetically high-risk horses and enable a more targeted – and therefore less expensive – use of these methods.

The research team at the RVC have used genome wide information to derive types of stem cells known as ‘induced pluripotent stem cells’ (iPSCs) from horses at high and low genetic risk of fracture. These iPSCs can then be turned into osteoblasts, the cells that produce bone. This innovative method allows researchers to study bone from high and low risk horses in the absence of any environmental variability, thus giving them the chance to look closely at the purely genetic factors that underpin fracture risk in Thoroughbreds.

Furthermore, identifying the mechanisms which underpin genetic risk in horses will allow future research to develop novel therapies and interventions for high-risk horses to decrease their risk of catastrophic facture. Identifying horses at high genetic risk would also allow breeders to make informed breeding decisions to reduce the probability of breeding horses at high genetic risk of fracture. This project therefore has the potential to significantly improve the health and welfare of racing Thoroughbreds.

The research has been made possible by a grant awarded by the Alborada Trust, an organisation that supports medical and veterinary causes, research and education and the relief of poverty and of human and animal suffering, sickness and ill-health. 

Lead researcher, Dr Debbie Guest, Senior Research Fellow at the RVC, said “I am delighted to have received funding from the Alborada Trust for this project. Bone fractures are a common problem in racing Thoroughbreds and this work has the potential to make a significant improvement to Thoroughbred health and welfare.”