Mobile light therapy

A new way to advance the breeding season in mares is being developed following research into the use of light-emitting diodes (LEDs) to inhibit melatonin secretion.

 

Thoroughbred breeders aim to have foals born as soon as possible after the official birthday of January 1^st (in the northern hemisphere.) This gives them a head start in size and maturity when competing against other horses in the same age group, both at sales and subsequently at the race track.

However, breeding early in the year is at odds with the horse's natural breeding season, which occurs some months later.

Artificial light is commonly used to advance the breeding season in mares. When an early foal is desired, breeders will put the mare "under lights" - keeping the barn lights on in the winter, to mimic the lengthening days that initiate the natural breeding season.

The hormone responsible for controlling this seasonal variation in response to change in day length is melatonin. It is secreted by the pineal gland in response to darkness.

Researchers at the University College Dublin's School of Agriculture and Food Science, have been examining the effect of different levels of blue light on melatonin production.

Four healthy 5-year-old TB mares took part in the study, which was conducted around the vernal (spring) equinox, so the mares were accustomed to equal 12 hour periods of light and darkness. For the duration of the study the mares were housed in a light-tight barn with artificial lighting timed to mimic the conditions outside .

The researchers used LEDs (emitting blue light of wavelength 468nm) set in a head mask to investigate the effect of blue light on melatonin secretion in the horse. (Blue light (465–485 nm) has been found to be the most efficient for inhibiting melatonin secretion in humans.)

Blood samples were collected through indwelling catheters at the end of hour-long periods of exposure to dark or to varying intensities of light. The light was directed at either both eyes or just one eye.

All samples, except the first, collected after exposure to “daylight”, occurred during the dark phase of the 24 h cycle.

The results showed that blue light inhibited the production of melatonin. The inhibitory effect occurred regardless of whether the light was administered to one or both eyes.

Melatonin levels were significantly lower after exposure to 10 lux, 50 lux, 100 lux as well as barn light, than they were after an hour of darkness. Melatonin levels after exposure to 3 lux were not significantly different from those recorded in darkness.

Lead researcher Dr Barbara Murphy, concludes that “melatonin inhibition can be achieved by exposing a single eye to low wavelength blue light.” She adds that “this is a novel finding with important implications for management of artificial lighting regimens in horses.”

“The light mask represents a safe cost-effective method of administering timed low-level light to a single eye so that mares can be maintained outdoors in their natural environment, avoiding the costs of indoor maintenance, while effectively advancing the onset of the breeding season to meet industry timelines.”

Read more at equinescienceupdate.com

Study suggests fatter is naughtier

 

Being overweight is not just a problem in human health; recent research suggests that fat horses and ponies are more likely to misbehave than their more slender companions.

A study, Misbehaviour in Pony Club Horses: Incidence and risk factors, published in the Equine Veterinary Journal (EVJ) is the first of its kind to quantify the incidence of misbehaviour in a population of horses.

Conducted by Petra Buckley, Senior Lecturer in Equine Science at Charles Sturt University, New South Wales,the study involved 84 Pony Club horses from seven different Clubs in rural Australia. Over a period of a year owners kept daily records of horse management including nutrition, healthcare and exercise and recorded any misbehaviour.

Misbehaviour was classified as “dangerous” (such as bucking, rearing, biting or kicking) or “unwelcome” (including “pulling like a steam train”, playing up, resenting foot trimming, and being difficult to catch.)

The horses were checked by a vet every month to investigate any relationship between pain, such as lameness and back pain and misbehaviour.

Of the horses studied, 59% misbehaved at least once during the study year, either during handling or when ridden. Whilst the occurrence of misbehaviour during riding was low, at 3% of horses in each month, in more than half of these cases the misbehaviour was dangerous, and posed a serious injury risk to horse and rider.

Risk of misbehaviour was higher in horses that were fat or obese and in those that were ridden infrequently. Horses exercised more than three times each week were less likely to misbehave. The odds of misbehaviour during riding were more than twice as high when horses were fed daily supplements, such as roughage, concentrates and/or grain. Access to “good grass” was also associated with increased risk of misbehaviour, independent of any supplementary feed provided. Horses and ponies that were excessively fat were roughly three times more likely to misbehave.

This suggests a link between nutrition, exercise, body condition scores and misbehaviour, where higher body condition scores reflect dietary intake exceeding requirements, a problem that can be exacerbated by infrequent exercise.

The study includes recommendations to help prevent misbehaviour such as exercising at least three times a week and maintaining an optimal physique by more closely matching pasture and supplementary feeding to horses’ exercise levels and resulting energy requirements.

“Our results highlight the importance of considering horse body condition, nutrition and exercise in any investigation of horse misbehaviour” concludes Petra Buckley.

Read more at equinescienceupdate.com

Saddle slip may indicate lameness

Saddle slip may not be the result of an ill fitting saddle or asymmetrical back muscles. A recent study has shown that it is often a sign of hindlimb lameness.

The study, conducted at the Centre for Equine Studies at the Animal Health Trust in Newmarket , identified a significant link between hind limb lameness and saddle slip, showing consistent saddle slip in some horses with hind limb lameness, even when the lameness was fairly subtle and difficult to detect.

Saddle slip, in which the saddle slips consistently to one side, is a well-recognised problem in sports horses. It can occur for a variety of reasons, including asymmetry in the shape of the horse’s back, riders sitting crookedly and ill-fitting saddles.

Sue Dyson, Head of Clinical Orthopaedics at the Centre for Equine Studies, had also observed that saddle slip may occur because of hind limb lameness. The intention of the study, therefore, was to find out more about the interrelationships between the horse, saddle and rider and to document the frequency of occurrence of saddle slip in horses with hind limb lameness compared with other horses.

The research was undertaken by Line Greve, Intern at the Centre for Equine Studies, and Sue Dyson, and was presented at the British Equine Veterinary Association Congress in September 2012. It is thought to be the first study of its kind, and was supported by the Saddle Research Trust (SRT).

The study assessed 128 horses of varying size, age and type. The degree of lameness of each horse was graded; back shape and symmetry were measured and saddles assessed for symmetry and fit. Each horse was ridden by at least two riders and rider straightness plus weight were recorded. The grade of saddle slip, whether it occurred with more than one rider, and whether saddle slip was influenced by the direction of movement or the diagonal on which the rider was sitting were also noted.

The saddle consistently slipped to one side in 54% of horses with hind limb lameness, compared with 4% of horses with fore limb lameness, 0% with back pain and/or sacroiliac joint region pain and 0% of non-lame horses. The saddle usually slipped towards the side of the lame (or more lame) hindleg.

Diagnostic analgesia was subsequently used to abolish the hind limb lameness and this eliminated the saddle slip in 97% of cases.

Sue Dyson said: “Our findings emphasise the need to educate owners, veterinarians, physiotherapists, trainers, riders and saddle fitters that saddle slip is frequently an indicator of lameness, not necessarily a manifestation of an ill-fitting saddle or asymmetric shape of the horse’s back. Detection of saddle slip provides an opportunity for the owner, riders and trainers to detect low-grade and subclinical lameness, with important welfare consequences.”

Minimising the stress of weaning

What is the least stressful way to wean foals? A small scale pilot study compared three different procedures.

The research was carried out at the Graf Lehndorff Institute for Equine Science, Neustadt (Dosse), Germany, under the direction of Professor Christine Aurich. A full report of the study has been published in the journal Stress.

Different weaning procedures were used for each of three groups of mares and foals. Each group comprised 6 (or 5) mares and foals.

Methods of weaning used were:

• Group A (6 foals): all foals in the group were weaned at the same time

• Group B (5 foals): all foals were weaned at the same time, but were left with two mares with which they were familiar, but not related.

• Group C (6 foals): these foals were weaned by removing two mares from the group on each of three consecutive days

During the weaning process, the researchers monitored the foals' behaviour and movement. They also measured the concentration of cortisol in the foals' saliva, recorded their heart rate and variability, and their weight.

The results confirmed that weaning was associated with stress. All groups showed an increase in salivary cortisol on the day of weaning. In Group C the cortisol concentration remained elvated for two days.

Abrupt weaning with no further contact with adult animals seemed to be the most stressful. Foals in Group A lost weight for two days. They seemed more unsettled - spending more time moving about on the day of weaning. They also showed the most pronounced increase in heart rate.

Foals that were weaned in the presence of two familiar but unrelated mares, (Group B) seemed least affected by the weaning procedure. Of the three groups, they showed the least locomotion and vocalisation after weaning.

The researchers conclude: “Based on cortisol release and behavior, weaning is associated with stress but this was least pronounced in foals weaned in the presence of two familiar but unrelated adult female horses.”

Fixed time protocol for frozen AI

A fixed time insemination protocol described by researchers from Brazil could encourage a greater use of frozen semen in equine reproduction.

One of the reasons frozen semen is not more widely used for breeding mares is the need for insemination to occur close to the time of ovulation. This necessitates repeated ultrasound examinations when the mare is in season, making the technique time consuming and labour intensive.

For artificial insemination with frozen semen to become more widespread, a simplified routine is needed that is less labour intensive, but does not sacrifice fertility.

Bruno Ribeiro Avanzi and colleagues at the Department of Animal Reproduction and Veterinary Radiology, Universidade Estadual Paulista at Botucatu, used a fixed time insemination protocol to achieve conception rates comparable with those using a more traditional approach.

Semen from two stallions was used in the study. One stallion (A), a Westphalen, was of good fertility, the other, (B) a Mangalarga Marchador, was of poor fertility.

The semen was collected, processed and frozen using a standard method.

Twenty nine mares were enrolled in the study. The oestrus cycle was monitored by rectal palpation and ultrasound scanning. Once a pre-ovulatory follicle of at least 35mm diameter was present, each mare received an injection of the gonadotrophin releasing hormone deslorelin acetate.

Growth of the follicle was monitored every six hours, starting eighteen hours after the deslorelin. Half of the mares were inseminated when ovulation had been detected, the others were inseminated 40 hours after the administration of deslorelin regardless of whether ovulation had occurred or not.

All mares were inseminated into the tip of the uterine horn adjacent to the follicle.

For frozen semen from the fertile stallion, the researchers reported pregnancy rates of 46.7% (7/15) when bred 6 hours after ovulation, and 66.6% (10/15) for inseminations performed 40h after ovulation induction.

The less fertile stallion achieved pregnancy rates of 35.7% (5/14) when bred 6 hours after ovulation and 21.4% (3/14) for inseminations performed 40h after induction of ovulation.

The researchers conclude that insemination at a fixed time after ovulation induction is efficient. “The present data supports the feasibility of equine frozen semen as a technology to be widely used and spread since it reduces mare management and costs.”

Read more at equinescienceupdate.com

Single mutation affects horse gaits

Scientists in Sweden have announced an important discovery that helps explain how some horses are limited to “natural” gaits, while others are capable of additional gaits.

Nearly all horses use “natural” gaits (walk, trot, canter and gallop) without special training. Additional “ambling” gaits may occur naturally in some individuals, but usually only in certain breeds.

Researchers have identified a single gene mutation that enables horses to perform gaits such as running walk and pacing. The pace is a lateral two-beat gait; the two legs on the same side of the horse move forward together, unlike the trot, in which the two legs diagonally opposite each other move forward together.

Not only does the mutation play a crucial role in the horse's ability to perform “ambling” gaits, it also affects performance in harness racing.

Leif Andersson and his research team in the Department of Animal Breeding and Genetics, at the Swedish University of Agricultural Science were looking for a genetic basis for gaits in horses. Only some horses can pace, and they wanted to find out why.

 

They studied the genomes of 70 Icelandic horses that could perform extra gaits — 40 could pace, and 30 could perform other alternate gaits. They found that a single mutation in a gene called DMRT3 was strongly associated with the ability to pace. The mutation resulted in the production of a shortened form of the DMRT3 protein. Both copies of the gene were mutated in the pacing horses.

Andersson explained that horses without this mutation cannot move their right hindleg and right foreleg forward at the same time. But with the mutation the movement is not regulated so strictly and becomes more flexible.

“We suspected a strong genetic component, but were almost shocked when we discovered that a single gene, DMRT3, largely explained the genetic difference between pacers and non-pacers’” said Lisa Andersson, one of the PhD students involved in the project.

The researchers developed a diagnostic test and found that the mutation is widespread among horses that show alternate gaits like Tennessee Walking Horse from the USA and Paso Fino from South America.

The mutation must have originated over a thousand years ago, Andersson said, judging by its widespread distribution among breeds. The horses with this gene would have given a smoother ride and thus been kept and bred.

While Andersson's group were investigating the presence of the gene mutation in pacing horses, a second research team was investigating the expression of the DMRT3 gene in the spinal cord of mice.

Klas Kullander and colleagues in the Department of Neuroscience, at Uppsala University, found that the gene was expressed in a previously unknown type of nerve cell within the spinal cord.

Further investigation showed that the DMRT3-neurons cross the midline of the spinal cord, connecting the left with the right side. They also connect with motor neurons that control flexor and extensor muscles. It seems that, as well as coordinating the activity of flexor and extensor muscles, this network of nerve cells also controls the alternate movement of left and right limbs.

‘The discovery of the DMRT3 mutation is an outstanding example of how genetic studies of evolution in domestic animals can lead to basic new knowledge concerning gene function and important biological mechanisms’, said Leif Andersson.

‘It is truly great when this type of interdisciplinary collaboration results in such ground breaking discoveries. There was no information in the scientific literature on the function of the DMRT3 prior to the publication of our article. This protein is present in all vertebrates for which data are available, and it is likely that DMRT3 nerve cells have a central role for coordinating movements in humans as well’, added Klas Kullander.

More details at equinescienceupdate.com

BHA announces new Detection Times

The British Horseracing Authority has announced that it has adopted five new Detection Times for Romifidine, Salbutamol, Firocoxib, Butorphanol and the Romifidine/butorphanol combination.

These Detection Times are harmonised across the member countries of the European Horseracing Scientific Liaison Committee (EHSLC). The EHSLC has been investigating the detection times of commonly-used medications, in response to the need for more information on the time taken for drugs to be eliminated.

In addition, the BHA detection Time for Detomidine/Butorphanol has been harmonised with the Detection Time across Europe and raised from 48 to 72 hours. Most of these new Detection Times result from research performed at the Authority’s Centre for Racehorse Studies in Newmarket.

The “detection time” is the time at which the concentration of the drug (or its breakdown products) in the urine, is not detected using routine or standard methods, in all the horses in the study.

It is important to remember that “detection times” are not the same as “withdrawal times”. An additional safety margin should be added to allow for individual variation.

However, the figures will give some welcome guidance to veterinarians who have to advise on whether a horse is likely to test positive if treated in the days before a race.

Further information, including a downloadable sheet of all 31 BHA Detection Times, together with a full explanation of the limitations of the results, can be found on the Authority’s website

http://www.britishhorseracing.com/resources/equine-science-and-welfare/medication-control.asp

Information on withdrawal of supplements containing Devil’s Claw has also been added to the Notices section of the Authority’s Rules website, where further information the use of a number of medications can also be found.

http://rules.britishhorseracing.com/Orders-and-rules&staticID=126908&depth=2

Possible blood test for inflammatory airway disease?

Inflammatory airway disease (IAD) is a common cause of poor performance in the equine athlete. Affected horses may cough as well as showing exercise intolerance, but a definitive diagnosis is based on examination of bronchoalveolar fluid (BALF.) This involves passing a tube into a sedated horse’s lung. A small amount of fluid is introduced and withdrawn, and the cells that have been washed from the lung are collected and examined microscopically.

Research at a laboratory in France may lead to the development of a simpler test for IAD. Eric Richard and colleagues at the Frank Duncombe Laboratory at Caen have been investigating the value of a blood test for a protein present in the lung for identifying horses with IAD.

Surfactant protein D (SP-D) is produced mainly by specialised cells in the alveoli and bronchioles, but has also been found in joint fluid and in the reproductive tract. It plays a role in immune defences in the lung

SP-D is released into the blood stream in response to tissue damage, and is used routinely in human medicine as a marker for inflammatory lung diseases.

The study, which compared SP-D levels before and after exercise in horses with and without inflammatory airway disease, has been reported in the Equine Veterinary Journal.

The researchers found that IAD was associated with a detectable, though moderate, increase in SP-D levels in the blood.

Within the IAD-affected group, they found no significant correlation between serum SP-D concentrations and BALF cytology. Neither did they find a significant effect of exercise on serum SP-D concentration in either the IAD or control groups.

A non-invasive test for IAD would benefit both horse and owner, being less stressful for the horse and cheaper for the owner. However, the report's authors advise that more work is needed to understand the factors controlling blood levels of SP-D. They advise caution before applying their findings to clinical cases.

More details:  equinescienceupdate.com

Music and stress response in weanlings

Scientists at the University of Queensland have found that music therapy may help reduce the stress associated with weaning.

Twelve weanlings that had been raised together were divided into two groups, matched for temperament. At weekends, all weanlings were turned out together. On week days, one group remained in the paddock, while the other group was stabled, with or without soothing music. Eventually both groups had been stabled for five days with music and five days without.

During the music treatment weeks, the Forest Gump Main Theme by Alan Silvestri was played continuously from 09.00 to 15.00 h daily. This particular piece of music was chosen for its constant rhythm, continuity and predictable melody.

The research team recorded heart rates every day from 09.00 to 15.00 h using heart rate monitors. They also recorded each horse's behaviour.

They found that although music did not affect the median heart rate, it significantly reduced heart rate variability. Furthermore, behavioural measurements showed that weanlings were more relaxed, and spent more time eating rather than walking about the stable, when they were exposed to soothing music.

Twice a week the weanlings were exposed to stallions in nearby stables. This gave the research team the opportunity to assess the effect of music on the weanlings' response to stress.

They found that, when music was being played, the peak heart rate in response to stress was substantially lower and the duration of increased heart rate was shorter.

The researchers conclude that their findings suggest that stress responses in weanlings can be modified by playing music whilst in stables. They suggest that the application of music therapy to enrich the equine environment is an area that shows promise and requires further study.

Read more : equinescienceupdate.com

Legibility of hot iron brands

The debate about the use of hot iron branding for identifying horses is becoming as heated as the branding iron itself. Critics of the procedure maintain that it causes pain and stress, which is no longer acceptable since the advent of microchip technology.

Others point out that not everyone carries a microchip reader with them. At least brands are easy enough to read without special equipment. Or are they? Recent work suggests that hot iron branding is not as accurate a means of identification as its supporters claim.

Until recently, horses were generally branded but following concerns that the practice is unnecessarily cruel there has been a gradual switch towards the use of microchips. Branding has essentially been discontinued in the European Union, although it is still accepted in several countries. Breed registries claim that this traditional method is perfectly satisfactory and obviates the need for costly equipment. Typically, a brand will comprise a symbol to indicate the particular breed combined with a two-digit number to identify the individual animal.

Comparisons between the two methods for identifying horses have focused on how they are perceived by the animals: does either method cause more stress or more harm to the horse?

Surprisingly, however, no attention has been paid to the other side of the coin. There is no doubt that microchips can be unambiguously decoded, providing the necessary equipment is available, but how well can brand marks be read? The issue has now been examined by Jörg and Christine Aurich of the University of Veterinary Medicine, Vienna.

According to the study, reported in the Veterinary Journal, three breed experts could only accurately identify the brands on less than half of the horses presented to them.

To assess the legibility of the markings, the researchers asked three experienced people to record the brands of 248 horses participating in an equestrian tournament in Germany.

All three experts were able to recognize the breed symbols on about 90% of the animals. For about 84% of the animals the symbol was recorded correctly by all three people.

However, reading the two-digit numbers proved more problematic. While each of the three readers correctly read the numbers on about half of the horses, the correct number was recorded by all three of them for less than 40% of the animals.

Read more at equinescienceupdate.com

 

 

 

PCR beats serology for leptospira detection

Examining urine using a polymerase chain reaction (PCR ) technique is more reliable than serology for identifying horses infected with leptospirosis, according to scientists in Brazil.

Leptospirosis can cause various clinical signs, including abortion, uveitis, and kidney and liver disease. Sub-clinical infections also occur, in which infected horses show no signs, but carry and excrete the organism.

In a letter to the Veterinary Record, Hamond and others report the findings of a study that assessed the relative merits of serology and urine PCR for detecting Leptospira infection in horses.

Their research looked at four herds in Rio de Janeiro, Brazil. Previous cases of leptospirosis had been recorded in the herds, and none of the horses had been vaccinated against the disease.

Blood and urine samples were collected from all adult horses (144). Leptospira antibodies were found in 66 horses, and 89 horses had Leptospira DNA in the urine.

Over half of the Leptospira-positive urine samples came from horses with no Leptospira antibodies in the blood.

The authors conclude that in horses, “serology is a useful tool for detecting leptospirosis on a herd basis, but individual detection of Leptospira species carriers must rely on PCR.”

Read more at: www.equinescienceupdate.com

Role of bacteria in chronic laminitis

 

Recent research suggests that bacteria may play a more significant role in chronic laminitis than previously thought.

Its not uncommon for abscesses to form underneath the dorsal hoof wall in horses with chronic laminitis. But whether these are the result of aseptic destruction of the laminae, or the result of bacteria tracking up the horn tubules is a matter of debate.

A study, by Janet Onishi and colleagues, based at Rutgers University, New Jersey, USA, investigated whether horses with chronic laminitis had evidence of sub-clinical infection in the laminar tissue.

“The objective of this study was to establish whether bacteria colonize laminar tissue and whether horses with chronic laminitis have higher or different microbes in the laminar tissue compared to non-laminitic horses” they explained.

Hoof samples were collected in a sterile manner from five horses with chronic laminitis, and from eight horses with normal feet.

The researchers found that laminae from horses with chronic laminitis contained 100 times the number of bacteria than did laminae from unaffected animals.

Only a few bacteria, all Gram-positive organisms, were isolated from the laminae of the healthy horses. In contrast, the laminae from chronic laminitic cases contained many more bacteria. Again Gram-postive organisms predominated, including bacteria in the phylum Actinobacteria, and coagulase negative Staphylococci. Many of the bacteria were identified as potential pathogens.

“The bacteria recovered from laminar tissue of chronically laminitic horses are not only potentially pathogenic, but are also known to form biofilm infections. “

(A biofilm is a complex community of micro-organisms, typically attached to a surface. Bacteria within the biofilm may be less accessible to host defences and antibacterial agents. A common example of a biofilm is dental plaque.)

The researchers suggest that horses may develop chronic laminitis as a result of biofilm infections occurring after an initial episode of acute laminitis. “We propose that treating chronically laminitic horses is difficult because there is a bacterial component to the disease that is not understood.”

Read more at: www.equinescienceupdate.com

Scientists question training method

Research from the University of Sydney questions whether the round-pen (“Join-up”) training method made famous by Monty Roberts is really as humane as its supporters claim.

Lead researcher was Cath Henshall, an animal science masters degree candidate in the Faculty of Veterinary Science.

She explains: “This method of training is widely used around the world and the people that use it claim that it's a humane and kind way to train horses. They also claim that it works because the trainer is able to successfully mimic horse body language and horse behaviour.

“Our study casts doubt on both those claims. We believe that our research highlights the unpleasant underpinnings of round pen horse training and for that reason we caution against its widespread use because it uses fear to gain control of horses."

The technique relies on the trainer using movement and noise to drive the horse around the perimeter of the pen. The trainer gradually reduces their aggressive movements, after which the horse will eventually slow down and approach them.

The researchers used remote control cars to mimic the technique and to eliminate the role of the trainer in imitating the horse's body language.

They believe that the training outcomes were achieved as a result of 'pressure-release' and not the ability of the trainer, or a remote control car, to mimic horse behaviour. "Put simply,” said Henshall, “pressure-release works because the horse finds the pressure applied unpleasant and therefore the removal of the pressure rewarding.”

The response the horse makes immediately before the pressure is removed is what the horse thinks made the pressure go away. When put in the same situation in the future, it is likely to perform that same behaviour to obtain the outcome that it values – safety.

"We 'rewarded' the horses for stopping and turning towards the car with a period of 'safety', when the car didn't chase them as long as they kept facing it. We trained some horses to actually walk up to and touch the car," said Henshall.

“We found that the car is almost as successful as the human trainer, so we think that calls into question whether the horse is responding to the human as though they think the human is another horse. We also confirmed that the reason the training works is for the same reason all horse training and a lot of animal training works. So that it doesn't actually require that you understand horses' body language particularly well. It just requires that you're able to chase and not chase at the right time.”

"Given that we could train horses to produce similar, though not identical responses to those seen in round pen training, but in reaction to non-human stimuli undermines the claim that the human's ability to mimic horse behaviour is an essential component of the technique."

"Although neither Monty Roberts' method nor ours uses pressure applied directly to the horse's body, both apply a form of emotional pressure by scaring and then chasing the horse."

"Our results indicate that because these methods rely on fear and safety, the horse is forced to choose between being repeatedly frightened or remaining with the trainer. We question whether it is humane to rely on fear and its termination to train horses," said Henshall.

"Although it is appealing to think that horses in the round pen choose to follow their trainers because they are responding to us as though we are a horse, we believe that the use of fear has no place in genuinely humane and ethical horse training."

 

Read more at:

www.equinescienceupdate.com/articles/sqtm.html

 

 

Ten minutes of Low-Deep-and-Round may cause stress

Compared to other head and neck positions, horses ridden in hyperflexion, or “low deep and round” are likely to be exposed to higher levels of physiological stress, according to work presented recently at the International Equitation Science Conference in Edinburgh.

Previous studies explored the effects of the hyperflexed head and neck position on the stress and behavioural responses of horses on the lunge or a treadmill. This study, by Dutch and Danish researchers measured a variety of behavioural and physiological responses of horses ridden in hyperflexion and two other common head and neck positions.

Fifteen Danish dressage horses training at medium to Grand Prix level and routinely ridden in the hyperflexed head and neck position were used. In addition to hyperflexion, low deep and round, the standard “on the bit” or competition frame and loose frame in which there was less tension in the reins were also investigated. Each rider performed a pre-determined riding test of 10 minutes duration in walk, trot and canter in each of the three head and neck positions, randomised over the three days of testing.

Heart rate, heart rate variability, salivary cortisol concentration, behaviour and the tension in reins were recorded during the 10-minute test period. Salivary cortisol concentrations were measured 60 minutes before and 0; 5; 15 and 30 minutes after the test.

“This study is the first to test whether there is an acute stress response to the hyperflexed head and neck position in horses ridden in a typical training environment” said Dr Machteld van Dierendonck from Utrecht University. “We found that the increases in salivary cortisol concentrations from baseline were significantly higher after 10 minutes of riding in the hyperflexed position than the increases observed in the competition head position or with the loose frame.“

Cortisol is known as the ‘stress’ hormone and increased cortisol concentrations are routinely used to quantify stress responses in animal welfare studies.

“We didn’t find any significant differences in heart rate, and heart rate variability between the treatments, but we did find that certain behaviours were higher during hyperflexed riding than the other head positions. Rein tension during the hyperflexed and competition head position was significantly greater than during the loose frame position.”

“Compared to previous studies which have used side reins to maintain the hyperflexed position, the low, deep and round position in this study was less hyperflexed.” she said.

“We wanted to test the horses’ response to this method in a typical training environment. Within the parameters of this training situation, we found that the use of the hyperflexed head position, even in horses routinely ridden this way could result in a physiological stress response as measured by salivary cortisol concentrations.”

“Interestingly, riders indicated a loss of balance and steering control in the loose frame”.

Head and neck positions has been the subject of controversy with the FEI conducting two reviews in recent years.

This study was a joint work with Danish and Dutch universities. Janne Winter Christensen from Aarhus University in Denmark, along with Mirjam van Dalum, Mandy Beekmans from Utrecht University were joint researchers on this study.

Read more at www.equinescienceupdate.com

Effect of weather on equine flu outbreak

Analysis of the recent Australian equine influenza outbreak has improved understanding of how the disease spreads.

Researchers from Australia and New Zealand looked back at the outbreak, which took place between August and December 2007. It was estimated to have cost the Australian equine industry over $350 million. Almost 70,000 horses on more than 9000 premises in Queensland and New South Wales were affected. The country had previously been free of the disease.

Simon Firestone, lead researcher and PhD candidate at the University of Sydney's Faculty of Veterinary Science. and colleagues matched meteorological data with information from infected premises to assess the effect of the weather on the spread of infection.

They discovered an association between the occurrence of new cases and the weather conditions three days previously. This coincides with the incubation period for equine flu – the first signs are usually seen from 3 days after the animal becomes infected.

The researchers found that horses were more likely to get infected on drier days when relative humidity was low. There was minimal risk once relative humidity exceeded 80%.

Infection was also less likely on days when the maximum daily air temperature was between 20 and 25°C. Extreme temperatures, either high ( >28°C) or low (<16°C) were associated with the highest risk of infection. Lower minimum daily temperatures were associated with higher risk of infection.

The researchers also found that wind speeds in excess of 30km/hour from the direction of infected premises were associated with increased risk of infection.

 

In conclusion, the authors write: “by combining influenza outbreak and concurrent meteorological data, we have shown how relative humidity, air temperature and wind velocity combined to influence the spread of an actual influenza outbreak.

Read more at equinescienceupdate.com

Standing fracture repair in racehorses

New research shows lower limb fractures in racehorses repaired under standing sedation have a similar outcome to those repaired under general anaesthetic, but with the advantages of less time, cost and risk.

The study, conducted by Richard Payne and Polly Compston at Rossdales Equine Hospital, Newmarket, has been published recently in the Equine Veterinary Journal.

The report includes details of racehorses with lower limb fractures that were repaired by Rossdales Equine Hospital up to June 2011. Thirty four racehorses were included in the report - thirty Thoroughbreds and four Arabs.

After premedication with acepromazine, sedation was maintained with i.v. boluses of detomidine and butorphanol. Local analgesia (high 4- (or 6-) point block) together with a ring block was performed by the operating surgeon.

Non-displaced fractures included in the study were: incomplete sagittal fracture of the proximal phalanx (14/34 ); lateral condylar fracture of the third metacarpus (12/34); medial condylar fracture of the third metacarpus (7/34 ) and 1 lateral condylar fracture of the third metatarsus. Repair was achieved by the insertion of one or more lag screws.

Hospital records, owner and trainer telephone questionnaires and website research were used to evaluate follow-up. The short and long-term results achieved were comparable with those for similar procedures carried out by the same surgeon under a general anaesthetic. Twenty of the horses returned to racing within an average of 226 days.

On average, the time from completion of the repair to the horse returning to racing was actually shorter when carried out under sedation, than similar cases repaired under general anaesthesia. However, the authors point out that horses selected for standing repair were those with non-displaced fractures which would be expected to require less time to heal than those with displaced fractures that required repair under general anaesthesia.

The authors stressed the need for a competent and experienced hospital team to ensure that health and safety concerns did not become an issue.

“Over the past few years we have been developing an increasing number of techniques, which allow us to perform a variety of surgical procedures in the standing horse. This negates the risks associated with general anaesthesia in our equine patients, which are especially relevant for horses with broken legs, because of their risk of re-injury to the site of fracture repair when the horse stands up again after recovery from anaesthesia” said Richard Payne. “Polly’s study showed that the outcome for racehorses that have a standing fracture repair is every bit as good as for those where the fracture is repaired under a general anaesthetic.”

 

Read more at equinescienceupdate.com

Seasonal variation in metabolic rate in ponies

Shetland ponies can drop their body temperature to save energy when food is scarce, according to a study carried out in Germany.

Warmblooded animals can keep functioning in cold conditions, but to do so they expend much energy maintaining their body temperature. Some primitive species seemed able to allow their temperature to fall to conserve energy. It was thought that animals lost this ability as a consequence of domestication. But recent studies have shown that the Przewalski horse, the primitive relative of the modern day horse, seems to have retained the ability to control its body temperature according to the environmental conditions.

Lea Brinkmann and colleagues at the University of Göttingen, Germany, wanted to see if this characteristic was still present in domesticated animals.

They conducted a study to see if Shetland ponies, one of the earliest domesticated breeds, retained the ability to drop their body temperature when food is scarce.

The research team studied a group of ten Shetland ponies throughout the year, monitoring subcutaneous and rectal temperatures, heart rate, general body condition and activity levels.

They noticed that, during the summer, the animals’ subcutaneous temperatures dropped over night, being lowest around dawn, and rose to a peak around mid-day. “This is consistent with a daily shallow hypometabolism,” the team says.

Then at the onset of winter, the researchers divided the ponies into two groups. One group received full rations; the other ponies were fed a restricted diet providing only 30% that of the control group.

The feed-restricted group had significantly lower daily subcutaneous temperatures compared with the control group on cold winter days, when the ambient temperature fell below 0°C. Mean heart rate and locomotor activity closely followed the ambient temperature.

Feed-restricted ponies showed a significant drop in average heart rate (from 52.8 beats per minute in summer) to 29bpm in winter. This response differed significantly from that of the ponies on full rations, suggesting that the feed restricted ponies had a lower metabolic rate.

Ponies were significantly less active in the winter than in the summer.

“Our results show that Shetland ponies exhibit signs of a winter hypometabolism indicated by reduced heart rate and subcutaneous temperature” the team conclude. “Thus, domesticated horses seem to have maintained the capacity for seasonal adaptation to environmental conditions by seasonal fluctuations in their metabolic rate.”

Read more at equinescienceupdate.com

Ticks wanted dead or alive!

The Western College of Veterinary Medicine (WCVM) in Saskatchewan, Canada, have launched a study into tick borne disease in the area.

A research team headed by Dr. Katharina Lohmann has initiated a pilot study into the prevalence of equine granulocytic anaplasmosis (A. phagocytophilum infection) and Lyme disease (Borrelia burgdorferi infection) in Saskatchewan horses. Both bacteria are transmitted in Canada primarily by the black legged tick, Ixodes scapularis. 

Curently, these infections are not common in Canada. There have been only three cases of anaplasmosis reported in horses in the country, one of which was found in Saskatchewan in 2010. 

Dr Lohmann explains that Ixodes scapularis is not thought to be established in Saskatchewan, but individual ticks may be carried in from different areas of the country and from the U.S. by migrating birds.

The first phase of the study will examine blood samples collected from horses in Saskatchewan, Manitoba and Ontario. The research team expect to find antibodies to A. phagocytophilum or B. burgdorferi in about two per cent of horses.

In order to better understand which species of ticks are relevant to horses, the researchers are asking veterinarians and horse owners to submit any ticks found on horses within Saskatchewan.

So far, the species of tick submitted to the survey includes Dermacentor albipictus (winter or moose tick), Dermacentor andersoni (Rocky Mountain wood tick) and Dermacentor variabilis (American dog tick).

The WCVM research team would be pleased to receive ticks of any life stage (including larva, nymph and adult stages) and are actively seeking tick submissions over the next two years (2011-2013).

More details of the tick survey, including how to submit ticks found on horses, are available at:

http://www.usask.ca/wcvm/veterinarians/equine_ticks.php

 

Unexpected outcome of Hendra virus cases

A survey of equine veterinary practices in Queensland Australia has shown that veterinarians are stopping doing equine work because of the risks posed by Hendra virus.

Hendra virus (HeV) infection primarily affects fruit bats, but was first reported in horses in 1994. During the initial outbreak 14 horses died. Seven other horses were shown to have been infected and were humanely destroyed.

Human infections, although uncommon, most  often affect people in contact with horses. Of seven cases of human HeV infection, five have involved equine veterinary personnel conducting post mortem  or endoscopic examinations. In three cases the infection was fatal.

A study, published in Emerging Infectious Diseases, explored the issues faced by  staff of equine veterinary practices relating to HeV infection-control and workplace health and safety.

 

The research team from James Cook University, in Townsville, Queensland, was led by Diana Mendez. They interviewed 21 veterinarians and other staff from 14 equine or mixed practices.

 

They found that twelve of twenty veterinary professionals  (60%) had dealt with one or more cases of HeV infection; seven of them (35%) had dealt with a confirmed case.

One finding that they had not expected was that some veterinarians had given up equine practice because of HeV. Four of 18 vets interviewed said they had stopped doing equine work, and 44% knew of one or more colleague who had stopped doing equine work in the previous year. Concerns over personal safety and legal liability related to HeV were given as the main reason for the decision to leave equine practice.

A vaccine against HeV is being developed. The availability of such a vaccine would go some way to calm the fears of those working in the Australian equine sector.

 

Read more at: www.equinescienceupdate.com

 

Equitation science - the road ahead

 The International Society for Equitation Science celebrates its 10th anniversary this year with a conference in Edinburgh, Scotland. Two days of talks and discussions on the science of horse riding and horse training are planned, followed by a practical day at the Scottish National Equestrian Centre

Details of the scientific program are now available on the ISES website...  

http://www.ises-uk2012.com/programme.htm

How horses recognise humans

Research just published from the University of Sussex demonstrates that domestic horses use a sophisticated cognitive system to identify individuals of species other than their own.

Drs Leanne Proops and Karen McComb, of the School of Psychology's Mammal Vocal Communication and Cognition Research Group, had already shown that horses can combine auditory and visual information to recognise each other.

In their latest research they demonstrated that horses also use this system to distinguish between the different humans they know.

Dr McComb explained: “When we hear a familiar voice we form a mental picture of who spoke. We match visual and auditory cues to recognise specific individuals. Previously we showed that horses also identify other horses cross-modally.

“We now demonstrate how flexible this ability is by showing that horses can also recognise humans in this way, despite people looking and sounding very different to themselves.”

The study was carried out using domestic horses that were accustomed to several different handlers.

Firstly the researchers tested where the horse would look when two voices - one familiar, one unfamiliar - were played from a hidden loudspeaker, either side of which stood the familiar and unfamiliar person.

They found that the horses responded more quickly and looked for longer and more often at the familiar human compared with the stranger when played their voice. They were significantly better at making this match when the familiar person was on the right of their visual field (indicating that the left hemisphere of the brain is involved in this processing).

The researchers then tested how the horses would perform the more complex task of distinguishing between two familiar voices.

This time, the horses were able to match a specific familiar voice to its human handler. This indicates, say the researchers, that the sight of the handler activated a multi-modal memory of that specific individual, allowing each horse to match the sight of a particular person with the sound of their voice.

Horses likely use this recognition strategy naturally to identify numerous individual people in their day-to-day lives.

Read more at: www.equinescienceupdate.com

Clydesdale bog spavin survey

Clydesdale horses would benefit from their owners knowing more about the likely causes of bog spavin, the chronic fluid distension of the tarsocrural (hock) joint.

A survey of Clydesdale owners in the USA and the UK found that most knew of the condition, but were often unaware of its possible significance.

Of the 93 5  horses included in the survey, 10% were reported to show signs of bog spavin. Over half of the affected animals first showed signs of bog spavin before they reached one year of age. This is significant as it coincides with the time when osteochondrosis tends to occur.

Osteochon drosis, a disorder of bone development which results in damage to the articular cartilage, is the most common cause of long term joint swelling in young horses showing little or no lameness. If untreated, the condition may eventually result in osteoarthritis and persistent lameness.

The owners' approach to the condition differed on opposite sides of the Atlantic. In the UK, nearly half of the affected horses were not investigated at all, whereas in the USA over 75% received some investigation – ranging from physical examination by the owner, yard manager or veterinarian, to more specialised techniques.

Radiographic examination was performed on 37.7% of affected horses in the USA , but on just 12.2% in the UK.

Some of the cases of bog spavin identified in the survey could be due to undetected osteochondrosis. The report's authors suggest that a radiographic survey of Clydesdale horses is warranted to establish the true extent of osteochondrosis of the hock joint.

They argue that if more owners knew about the possible causes of bog spavin they might be more likely to investigate and thus identify those horses with osteochondrosis. Arthroscopic surgery could then be offered to appropriate cases to reduce the risk of osteoarthritis.

Read more at www.equinescienceupdate.com