Eclipse clone on the way?

News has emerged that scientists have successfully grown cells containing the DNA of Eclipse, the most famous racehorse of all time. This is the first, and most difficult step to producing a live cloned foal.

Eclipse, born two hundred and fifty years ago, is widely considered to be the greatest Thoroughbred racehorse ever. Unbeaten throughout his racing career from 1769-1770, Eclipse  was in different league to his contemporaries and won eight of his races by default –  “walk overs” - as no-one would put up a horse to run against him.

After retiring from racing he became a very successful sire. It is likely that there are very few Thoroughbred horses alive today that do not contain a link to Eclipse somewhere in their bloodlines.

His skeleton currently adorns the teaching block named after him at the Royal Veterinary College, London.

Attempts to recover DNA from his much studied skeleton proved fruitless, but samples of his tail hair which had been woven into the tassel of "The Whip”, the prize of victory in the self-named race, were found to contain sufficient undamaged genetic material for the scientists to work with.

A team from the University of London’s Department of Veterinary Embryology have been able to transfer DNA from Eclipse into the cytoplasm of cells from the subcutaneous connective tissue of a donor horse. These fibroblasts have then been proliferated in the lab and have been shown to have remained viable and to contain the replicated Eclipse DNA.

The next stage in the cloning process, which is due to start this month, will be the implantation of the chromosomal tissue into an egg from a donor mare and then the chemical signalling to trigger the egg to start the development into an embryo. After the recombined oocyte has been activated, it is transferred surgically to the oviduct of a recipient mare, which carries the foal to birth. If all goes according to plan, a cloned Eclipse foal could be born in early 2015.

Equine Grass Sickness Vaccine Trial

Following the successful completion of a Grass Sickness vaccine pilot trial last year, a full-scale  trial is due to start shortly throughout Great Britain.

Equine grass sickness (EGS) affects grazing horses, ponies and donkeys, and is nearly always fatal. Britain has the highest incidence worldwide. The current theory is that EGS is a toxico-infection involving Clostridium botulinum type C. Several studies have shown horses with natural immunity to Clostridium botulinum type C are less likely to get the disease.

Other equine clostridial diseases are successfully prevented by vaccination, so it should be possible to prevent EGS by vaccination.

The main purpose of last year's pilot study was to assess whether a larger-scale trial would be possible. So it was designed to test the methods and systems used rather than the vaccine itself.

A total of 48 horses and ponies were randomly assigned to the vaccine group and 47 were assigned to the placebo treatment group. All horses in the study completed the primary treatment course of three injections given 21 days part.

The researchers report that the pilot field vaccine trial was a huge success, meeting all of the study objectives. The findings have already been used to revise sample size calculations and trial methodology for the full-scale nationwide randomised placebo-controlled field vaccine trial.

Both the C. botulinum type C toxoid vaccine and placebo injection were shown to be safe.

No systemic adverse reactions (where the entire body may be affected and the horse or pony may become unwell) were reported following any injections administered during the pilot vaccine trial. Minor local injection site abnormalities (such as localised heat, pain or swelling at the injection site) were reported in 19 of a total of 372 injections administered during the study. None of them required treatment or veterinary attention.

There was no significant difference in the number of minor injection site abnormalities between the vaccine or placebo treatment groups.

The researchers report that the response to the vaccine varied, as they expected it would. Some horses showed an increase in antibody levels of up to eight times, but others showed a less marked response. This is in fact what tends to occur with other vaccines, such as influenza. However, it does mean that not all horses would be fully protected by the  vaccination.

This ground-breaking EGS vaccine trial aims to determine the efficacy of Clostridium botulinum type C vaccination in preventing EGS by comparing EGS incidence between groups of horses receiving vaccination or a placebo.

The plan is to recruit 1100 horses for a two year period from premises that have previously had a high incidence of EGS. Demonstration of reduced disease incidence in vaccinated horses would provide a major breakthrough in the prevention of EGS.

For more details see:
www.aht.org.uk/cms-display/egs_vt.htm

WormsAndGermsMap

Researchers in Canada have launched an interactive map designed to track infectious diseases in dogs, cats, and horses around the world.

The "Worms and Germs Map" can be accessed online, and is free to use. It is a companion to the educational site WormsAndGermsBlog. Both were developed by Scott Weese DVM DVSc DipACVIM of the University of Guelph and Maureen Anderson DVM DVSc PhD DipACVIM from the Ontario Ministry of Agriculture and Food.

Dr Weese explains: "This disease mapping site was developed because we perceived a need for real time tracking of companion animal infectious diseases and a need to foster more knowledge about infectious diseases amongst vets, animal owners and people in human medicine and public health.  It may also help track emerging diseases, diseases that have a changing range and allow for more rapid identification of outbreaks."

For more information, and to see what has been reported in your area, go to www.wormsandgermsmap.com 

Herpes infection webcast

The paralytic form of equine herpes infection ( EHV-1 myeloencephalopathy) seems to be occuring more commonly, leading to speculation that viruses with increased neurovirulence are circulating.

What can we learn from recent outbreaks? A free webcast, presented by Dr Nic Pusterla of UC Davis, promises to review the problem and highlight the latest developments in epidemiology, therapy and prevention.

See here for more details..

http://www.myhorseuniversity.com/node/755

Mucus production in RAO

Recurrent airway obstruction (RAO) or “heaves”, the equine equivalent of human asthma, is a common cause of poor performance and a significant welfare concern.

Severely affected animals show signs such as dilated nostrils, nasal discharge, and excessive chest movement. A "heave" line may be present. They may be incapable of any athletic activity. Mild cases may appear to breathe normally and require further investigation to confirm the diagnosis. However, most cases fall somewhere between the two extremes.

The signs are caused by a combination of increased mucus production in the respiratory tract and spasm of the muscles surrounding the airways. This results in narrowing of the airways, making it more difficult for the horse to breathe.

Recent research, funded by the Horserace Betting Levy Board, has been looking at the properties of mucus and the sites of its production in the lungs of horses with RAO.

An essential component of mucus is the mucins – high molecular weight proteins, produced by specialised cells such as those lining the respiratory tract. Their most important characteristic is that they can form gels, and so provide lubrication, transport and a physical barrier.

It was these mucins that formed the subject of this study. A summary of the work, carried out by Adele Williams as part of her PhD studies at the University of Manchester, has been published online.

Dr Williams found no difference in composition of the mucus between healthy and RAO-affected horses; the RAO cases just had more of it. Neither did she find any difference in mucin properties between horses housed inside or maintained at pasture.

The research showed that mucins were produced in cells lining the airways and in deeper glands. There was great variation in the size and number of these cells in both normal and RAO-affected horses. However, the mucin-producing cells in the deeper glands were larger in horses with RAO than in healthy control animals.

In the future it may be possible to use cell cultures to study mucus production in the laboratory, and to investigate ways of modifying mucus production. As part of the current project, mucin-producing cells were grown successfully in the laboratory for a short time. However there were problems with bacterial and fungal overgrowth. The technique needs to be refined before it can be used for analysing and modifying mucus production in the search for a treatment for mucus overproduction in horses with recurrent airway obstruction.

More details:

http://www.hblb.org.uk/documents/blog/RS242.pdf

Research Radio

Equine Guelph, the horse owner’s Centre at the University of Guelph, has launched a new service that aims to bring updates on the latest equine research carried out by scientists at the Ontario Veterinary College and the University of Guelph.

Research Radio, an online podcast  promises to the cutting edge discoveries being made, and explain what they mean for equine health and welfare. It is produced in association with  Trot Radio's Norm Borg and SSG Gloves.

The first two podcasts are now available. The first features Dr. Thomas Koch, Assistant Professor of Biomedical Sciences at Ontario Veterinary College, discussing his work on stem cell therapy. In the second, Dr. Jeff Thomason, Senior anatomy Professor and research co-ordinator at Equine Guelph, discusses the relationship between track surface and injury in the performance horse.


http://www.equineguelph.ca/research/radio.php

Owners of British horses that don't headshake needed to help understand headshaking!

An international group of researchers are looking for owners of normal healthy horses as well as owners of horses that headshake to complete a short online survey to help understand headshaking. They are trying to understand why some horses develop headshaking behaviour and others do not. With a better understanding it is hoped that more effective treatments can be developed.

The group have launched a simple online survey and the project is funded by UK based Science Supplements Ltd. The group want to hear from owners who have horses that headshake BUT just as importantly, from owners whose horses don't headshake. These horses will act as controls for the study.

To date the group have over 300 completed surveys from owners of horses that headshake and from over 400 that don’t. The group urgently need more surveys, especially from owners of horses that DO NOT HEADSHAKE. (Please note that at this time the survey is limited to horses in the UK)

The survey takes around 10 minutes to complete and can be found here:

https://www.surveymonkey.com/s/HEADSHAKING2014

Is crib-biting inherited?

Crib-biting, (or cribbing) is a stereotypic behaviour in which the horse grasps a fixed object with its incisor teeth, and draws air into the cranial oesophagus, before expelling it with a characteristic grunt.

Various factors have been suggested as a cause for the behaviour including gastric discomfort and lack of  sufficient environmental stimulation. But is there a genetic component?

Scientists at the University of Helsinki, Finland compared crib-biting and non-crib-biting horses, looking specifically at genes known or suspected to be related to stereotypic behaviours.

In particular they looked at genes such as Ghrelin, Ghrelin receptor, Leptin, Dopamine receptor, μ-opioid receptor, N-cadherin, Serotonin receptor and Semaphorin.

Two groups of horses were compared. Horses in the crib-biting group had started to display the behaviour at any early age, and had done so for at least a year. They tended to crib-bite after feeding or when stressed.

Non-crib-biting (control)  horses were all over ten years old and had never been seen to crib-bite.

The researchers analysed the candidate genes in both groups and compared the allele frequencies between the cases and controls for each breed separately. They could find no evidence of an association at any of the tested loci.

They conclude: “These results suggest that the previously known stereotypic genes are not major risk factors for crib-biting in horses.” They suggest that further whole genome studies involving larger groups of crib-biting and non-crib-biting horses are required.

More information

Detecting larval Strongylus vulgaris infections

 Collaboration between scientists in Denmark and the United States has led to the development of a diagnostic test that promises to help identify horses infected with the larval stages of the large strongyle Strongylus vulgaris. The larvae  migrate in the arteries that supply the large intestines and may cause blockage of the arteries and intestinal infarctions.

The result of the research is a serum enzyme-linked immunosorbent assay (ELISA) which has been validated for detecting migrating larvae in the bloodstream of horses. The test detects antibodies against a polypeptide in the excretory/secretory fraction of the migrating larvae, named SvSXP.

Further work using the test showed that foals receive colostral antibodies from the mare which may persist for up to 13 weeks of age. Foals start being able to mount their own immune response to the parasites from about three months of age, depending on the grazing conditions and the stage at which they were exposed to the parasites.

In younger foals, the serum ELISA does not give reliable diagnostic information despite heavy infections. The researchers found that young foals can be heavily infected without showing positive ELISA test results.

They also found that higher infection levels tend to be associated with higher ELISA levels.

Once they had started producing antibodies, foals continued to maintain high ELISA levels throughout the study. There was a tendency for the ELISA levels to decline gradually as the numbers of migrating larvae declined and adult intestinal worm burdens increased.

The scientists suggest that further research into the time taken for antibody levels to decline after effective anthelmintic treatment would be very useful.

If the test becomes commercially available it will be a useful addition to the armoury  of diagnostic tests for investigating parasitic disease in horses.

Read more at equinescienceupdate.com

Investigating sudden death in racehorses

Sudden death in athletic horses is a rare but distressing event. By definition, affected horses were, moments before, perfectly fit and healthy. The absence of any premonitory signs  complicates the task of identifying causative factors.

Recently Catriona Lyle led a multicentre study in an attempt to gain a better understanding of the problem and find ways to reduce the risk of sudden death occurring. The work,  funded by a Horserace Betting Levy Board scholarship, was undertaken at the Royal (Dick) School of Veterinary Studies in Edinburgh.

Lyle coordinated the study drawing information from racecourses in North America, Australia, Japan and Hong Kong. Post-mortem data from 284 cases over 20 years were studied. In the UK post-mortem examinations are not always carried out in cases of sudden death and so gaining access to these international records was essential.

She explains:“The study has shown that the cause of death can be quite variable, ranging from severe lung bleeding to a pelvic fracture that causes massive bleeding into the abdomen. But in approximately half the cases I studied, the pathologist was uncertain as to the cause of death. The most likely explanation for death in these situations is cardiac rhythm irregularities, but this is very difficult to prove.”

Following her analysis of these international data, Lyle then looked at cases of sudden death in British racehorses. She found that sudden death of horses during races is a very rare event. Over a seven year period, in 705,914 race starts, there were 201 sudden deaths on British racecourses. The same syndrome is known to occur in eventing, show jumping and hunting but statistics have not been established in these sports.

In the UK study, she found that increasing age is a risk factor, steeplechases posed more of a risk than flat races and racing during the summer was associated with a greater risk of sudden death. However, this should be put in the context that, on average, steeplechasers are older than hurdlers or Flat horses. Horses that had raced within the last 60 days were less likely to be affected.

Read more at equinescienceupdate.com

All you need to know about equine hormonal disorders?

Up to date information on equine hormonal disorders has just become easier to find thanks to the Equine Vet

Journal and Equine Veterinary Education. They have compiled a free online collection of their recent articles on Equine Endocrinology to raise awareness of these common disorders and to provide a source of references all in one place.

“Raising awareness of the benefits of early diagnosis [of these conditions] and sharing the latest research on these and other associated conditions are imperative to provide horse owners with the best diagnostic and treatment programmes for their horses” said Professor Celia Marr, Editor of Equine Veterinary Journal.However. “It is easy to under-estimate obesity: horse owners need to think about improving management of their horses’ feeding and exercise in order to avert problems before they become a veterinary issue.”

The virtual supplement is available (free) at:

http://onlinelibrary.wiley.com/journal/10.1001/%28ISSN%292042-3306/homepage/equine_endocrinology_virtual_issue.htm

Filling a gap in equine history

Scientists have announced the discovery of a new species of fossil horse from 4.4 million-year-old fossil-rich deposits in Aramis, Ethiopia.The findings have been reported in the Journal of Vertebrate Paleontology.

The animal had limbs with three toes and was about the size of a small zebra. It has been named  Eurygnathohippus woldegabrieli after Giday WoldeGabriel, a geologist at Los Alamos National Laboratory. The research team wanted to recognize his many contributions in unraveling the geological complexities of the deposits in the Ethiopian Rift system where fossils of some of our oldest human ancestors have been found.

The horse fills a gap in the evolutionary history of horses but is also important for documenting how old a fossil locality is and in reconstructing habitats of human forebears of the time, said Scott Simpson, co-author of the research and professor of anatomy at Case Western Reserve University's School of Medicine, in Cleveland, Ohio. "This horse is one piece of a very complex puzzle that has many, many pieces."

The researchers found the first E. woldegabrieli teeth and bones in 2001, in the Gona area of the Afar Region of Ethiopia. This extinct species of horse was among the diverse array of animals that lived in the same areas as the ancient human ancestor Ardipithecus ramidus, commonly called Ardi.

"The fossil search team spreads out to survey for fossils in the now arid badlands of the Ethiopian desert," Simpson said. "Among the many fossils we found are the two ends of the foreleg bone—the canon—brilliant white and well-preserved in the red-tinted earth."

A year later, they returned and found part of the connecting shaft, which was split lengthwise but provided the crucial full length of the bone. The long slender bone indicates this ancient species was an adept runner, similar to modern zebras, and analyses of their teeth indicated they relied heavily on eating grasses in the grassy woodland environment.

E. woldegabrieli had longer legs than ancestral horses that lived and ate in forests about 6 million to 10 million years ago, Simpson said. The change helped them cover long distances as they grazed and escape lions, sabre-tooth cats and hunting hyenas that would run down their prey.

Other fossils they found included teeth, which are taller than their ancestors' and with crowns worn flatter—more signs the horses had adapted to a grazing life. Analyses of the isotopic composition of the enamel confirmed that E. woldegabrieli was a dedicated grazer with a coarse diet similar to that of modern zebras, wildebeests, and white rhinoceroses.

"Grasses are like sandpaper," Simpson said. "They wear the teeth down and leave a characteristic signature of pits and scratches on the teeth so we can reliably reconstruct their ancient diets."

Raymond L. Bernor, from the Laboratory of Evolutionary Biology at the Howard University College of Medicine in Washington D.C., led the fossil analysis. The bones, which are kept at the National Museum of Ethiopia in Addis Ababa, Ethiopia, showed this animal differed significantly from both horses more than 5 million years old, and those 3.5 million years old and younger. Members of the youngest group are even taller and have longer noses, further adaptations toward living in open grasslands, the researchers say.

More information:
Eurygnathohippus woldegabrieli, sp. nov. (Perissodactyla, Mammalia), from the middle Pliocene of Aramis, Ethiopia.
Bernor RL, Gilbert H, Semprebon GM, Simpson S, Semaw S.
Journal of Vertebrate Paleontology, vol. 33, no. 6; pages 1472-1485
doi: 10.1080/02724634.2013.829741

Equine influenza: Are we protecting our horses effectively?

Should we be doing more to protect our horses against equine influenza?

Vaccination against equine influenza became mandatory for racing Thoroughbreds in the United Kingdom in 1981. Since then major outbreaks have been few and far between. Vaccination has two aims: to protect the vaccinated individual from becoming ill and to limit the spread of infection by reducing the amount of virus a vaccinated horse will shed if it does become infected.

The flu virus can change the proteins on its surface, a process known as antigenic drift. These surface proteins are the structures that are recognised by the immune-system. If they change, a vaccine that has been produced to recognise proteins on older virus strains will be less effective. The World Organisation for Animal Health (OIE) monitors field surveillance data and recommends suitable vaccine strains to be included in commercial vaccines. None of the vaccines currently on sale in UK have the most recently recommended strains and only one in the US achieves this.

Read more...

New Codes of Practice for 2014

Codes of Practice for the 2014 equine breeding season have been published by the Horserace Betting Levy Board. The Codes set out voluntary recommendations to help breeders, in conjunction with their veterinary surgeons, to prevent and control specific diseases in all breeds of horse and pony. Information can be found on Contagious Equine Metritis, Equine Viral Arteritis, Equine Herpesvirus, Equine Coital Exanthema, Equine Infectious Anaemia, Dourine and Strangles.

The sections on Equine Herpesvirus and Strangles have been updated and expanded for 2014. For more details see:

http://codes.hblb.org.uk/index.php/page/2

3D printing future for therapeutic shoes?

Australian vets and scientists from CSIRO (Commonwealth Scientific and Industrial Research Organisation)  have given a surprise Christmas gift to ten-year old mare, Holly, who suffers from chronic laminitis.

She recently took the first steps in her new 3D printed titanium shoes that were custom designed to fit her foot. 

The team of 3D printing experts worked with horse podiatrists to scan Holly's feet and design the “horse-thotic” which aims to support the foot and encourage it to heal, whilst making Holly comfortable.

Holly has had laminitis for three years. Horse vet and farrier, Dr Luke Wells-Smith from the Equine Podiatry and Lameness Centre, said his team saw the 3D printed shoe CSIRO built for a race horse earlier this year and started to think about using 3D printing to rehabilitate lame horses.

"The new shoes will work to redistribute weight away from the painful areas of the laminitic foot and give Holly, and horses like her, the chance to recover," he said.

"Many attempts have been made in the past to cure laminitis but it’s the 3D scanning and design part of this process that is so exciting to us.

"Christmas is looking a lot merrier for Holly this year. She should be walking normally and without pain in just a few weeks," said Luke.

CSIRO's 3D printing expert, John Barnes, said scanning the hoof would allow them to manufacture a shoe that is the ‘perfect fit’ for these complicated foot diseases, giving the horse the best possible chance for rehabilitation," he said.

"We know that 3D printing has the potential to create so many advanced biomedical products, but rehabilitation of horses has been a completely new area of work for CSIRO.

"We’re glad that this technology is opening so many doors and is now helping to aid the rehab process for these animals and get them walking comfortably again," he said.

See the video:

http://csiro.au/Portals/Media/Hollys-Christmas-wish-comes-true.aspx

Limiting roughage access may limit fertility

Ensuring that mares have access to roughage throughout the day and night has beneficial effects on reproductive efficacy according to a recent report.

Horses have evolved as "trickle feeders" and are adapted to eating little and often. Modern management methods frequently interfere with this natural feeding routine, and have been implicated in causing welfare problems and  health issues such as gastric ulcers and colic.

Now evidence has emerged to suggest that restricting the availability of ro ughageto just part of the day can be detrimental to breeding performance.

The study, “Temporal feeding pattern may influence reproduction efficiency, the example of breeding mares” by Haifa Benhajali and colleagues has been published in the journal PLOS One.

One hundred Arab breeding mares on the national breeding facility of Sidi Thabet, near Tunis, in Tunisia, were included in the study. They were randomly divided into two groups whose management differed only in the timing of availability of roughage. Mares were housed individually except for a period of six hours when they were turned out into a paddock. They had free access to water, a small amount of cut grass was given at midday, and 4kg of barley was fed overnight.

The “Continuous feeding pattern” group (CF) had access to hay both when turned out and when housed for the rest of the day and night. They received 5kg hay in the stable at night and 5kg hay when turned out. The “standard feeding pattern” group (SFP) received 10kg hay only when housed. So the total amount of roughage provided each day for both groups was the same.

The researchers found a significant difference between the two treatment groups. Those receiving hay throughout the day had fewer oestrus abnormalities and higher fertility. The conception rate in the CF mares was 81% compared with 55% in the SFP mares.

They conclude that “temporal patterns of feeding may be a major and underestimated factor in breeding.”

For more details see:

Temporal feeding pattern may influence reproduction efficiency, the example of breeding mares.
Benhajali H, Ezzaouia M, Lunel C, Charfi F, Hausberger M.
PLoS One. 2013 Sep 30;8(9):e73858. 

doi: 10.1371/journal.pone.0073858

How risky is medicating joints?

Injecting medication directly into the joint is a common procedure for treating injuries in competition horses. It carries a risk of introducing infection into the joint. However, a recent report suggests that with adequate preparation serious consequences are uncommon.

Lewis Smith and colleagues examined clinical records of all horses given intra-articular injections by nine ambulatory veterinary surgeons over a five year period. The vets were based at a specialist equine practice in Newmarket England dealing mainly with Thoroughbred racehorses. Data relating to intra-articular injections for diagnostic purposes were not included in the study.

The site of injection was prepared using standard aseptic technique, but usually the hair was not clipped.  All injections were made using scrupulous aseptic injection technique.

During the study period, 9456 injections were performed, including corticosteroids (92.3%) antibiotic (amikacin)( 94.8%) and polysulphated glycosaminoglycans (PSGAGs)(0.15%).

Twelve horses developed complications after medication. Four of those developed joint sepsis, but all returned to work after having the joint flushed.

Analysis of the data showed that administration of PSGAGs into the joint, was significantly associated with joint infection. Overall, intrasynovial medications that included amikacin were less likely to develop joint sepsis, but the difference was not significant if the PSGAGs were excluded from the analysis.

The authors concluded that the risk of  sepsis being induced inadvertently following intrasynovial medication was extremely low. They advised that intrasynovial medication with PSGAGs should be  avoided unless antimicrobials are given at the same time.

For more details see:
Risks of synovial sepsis following intrasynovial medication in ambuatory practice, 2006-2011: 9456 intrasynovial injections. Smith, L., Palmer, L., Shepherd, M., Steven, W.N., Dallas, R., Baldwin, G., Sommerville, G., Hawthorne, T. and Ramzan, P.
Equine Veterinary Journal (2013) 45, Suppl. 44, 6  (no11)

NEW LAMINITIS STUDY

A new research project aiming to help horse owners reduce the impact of laminitis is being undertaken by the Animal Health Trust (AHT) in partnership with the Royal Veterinary College (RVC).

The study, which will extend over four years, is being funded by World Horse Welfare. It will take a closer look at management factors that may contribute to the development or recurrence of laminitis within the British horse and pony population. Through modifying these contributing factors, it is hoped that horse owners can significantly reduce the impact of this important welfare problem.

The AHT and RVC plan to create a website where owners from all over the country can register their horses and ponies and assist in the regular gathering of information related to potential risk factors for laminitis, over a period of two years.

This will help establish a timeline of events and gain a better understanding of the factors leading to laminitic episodes.

The study, to be conducted by PhD student Danica (Dee) Pollard, will follow-up on previous research conducted by Dr Claire Wylie in which factors such as rapid weight gain, increasing time since last deworming, box rest in the previous week and new access to grass in the past month increased the risk of laminitis.

Dr Wylie’s study also revealed that factors such as feeding of additional supplements and transport in the previous week were associated with a reduced risk of laminitis. 

These are factors that could all be changed by the owner, and this is why they are of particular interest to the new study.

Dee Pollard, based at the AHT, said: “This will be a very exciting opportunity for owners to be at the frontline of equine health research and contribute to a study which aims to provide evidence-based preventative strategies to combat laminitis.”

Horse owners interested in taking part in the research project are asked to register their interest via email to danica.pollard@aht.org.uk

Acceptability of smaller microchips

Although microchips are widely used for identifying horses throughout Europe, there is still some resistance to their use, with questions being raised about stress during implantation, inflammation at the site of implantation, and reliability of detection.

In response to this criticism, microchips that are even smaller have been developed. They may be less stressful to implant, but do they work as well? Recent work has looked at whether such chips are reliable and if their implantation causes signs of stress.

The study, carried out at the Brandenburg State Stud at Neustadt (Dosse), Germany, was  reported by Manuela Wulf and others in a recent edition of the Veterinary Record. Forty adult mares were implanted,  on the left side of the neck, with a reduced-size microchip (10.9×1.6 mm). (Conventional microchips are 11.4×2.2 mm). Three different scanners were used to detect the microchips  immediately, and on three further occasions up to 28 weeks after implantation.

The researchers found that scanners differed in their ability to read the microchips, although all scanners detected all chips on every occasion when scanned from the side of implantation. One scanner read all microchips successfully from both sides of the neck on four occasions up to 28 weeks after implantation.  Two other scanners detected all of the chips from the side of implantation, but were less successful reading from the “wrong” side of the neck.

Did the horses find the implantation procedure stressful? The researchers monitored heart rate, heart rate variability and saliva cortisol levels during the implantation process in twelve of the mares. They also recorded the same information while pressing at the implantation site with a cannula without penetrating the skin. So each mare acted as its own control. They found a slight increase in heart parameters in both chip implantation and controls, but no change in cortisol levels.

The report's authors conclude that reduced-size microchips are highly reliable for identification of horses. “Compared with conventional microchips, the reduction in size did not impair readability. Microchip implantation is no pronounced stressor for horses.”

For more details see:
Reduced-size microchips for identification of horses: response to implantation and readability during a six-month period.
Wulf M, Aurich C, von Lewinski M, Möstl E, Aurich JE.
Vet Rec. 2013 Nov 9;173(18):451.
 doi: 10.1136/vr.101824

Riding Arena Footing and Management Webcast

Ever wondered what's involved in providing a top quality arena surface, or wanted to know more about the materials to use?

Here's your opportunity. There's a free webcast on “Riding Arena Footing and Management” from MyHorseUniversity on November 26, 2013 at 7 PM ET.

Dr. Ann Swinker, Associate Professor in Equine Sciences, Penn State University and Horse Extension Specialist has been involved in the horse business for over 35 years. She will discuss the physical properties of the various footing materials that are available and the advantages and disadvantages. She will also consider the management of arena surfaces, the principles of maintenance and the signs that a surface needs to be changed or replaced.

You can register for the webcast now. Don't worry if you miss it; you can still catch it later, as it will be archived on the website and will continue to be available (free).

For more details go to ....

http://myhorseuniversity.com/resources/webcasts/ridingarenafooting

Benefit of targeted worming

Worming only those horses that need it can be cost effective, even taking into account the cost of performing faecal worm egg counts, according to research published in the Veterinary Record.

It is now widely acknowledged that a targeted approach to worm control is preferable to interval dosing regimes. Current recommendations are that only those horses carrying a moderate or high worm burden are treated; thus ensuring that worms are not exposed to anthelmintics needlessly.

Faecal worm egg counts (FECs) are used to determine which horses need (or don't need) treating. To many owners this may seem an unnecessary expense. However, recent work has shown that using FECs in this way helps reduce the overall cost of worming.

Hannah Lester, with colleagues at the Moredun Research Institute, and the Universities of Bristol, Liverpool and Edinburgh, monitored FECs at 3 monthly intervals over a nine month period. In all, 368 horses from 16 separate yards were involved in the study.

Horses with FECs greater than 200epg were treated, with pyrantel (in March and June) and ivermectin (in September). All horses received moxidectin/praziquantel in December.

The researchers compared the cost with that of a standard interval regime of two treatments with moxidectin and two of moxidectin and praziquantel - which is what had been common practice in the study population.

They  estimated the cost of the two approaches by using average prices for anthelmintic products and faecal egg counts that they obtained off the internet. Even allowing for the cost of faecal egg count reduction tests  (ie repeating the FEC after each treatment to check the anthelmintic had been effective)  they found that, over the year, there was an average saving per yard of £294.44.

They conclude: “these findings support the notion that targeting anthelmintic treatments at those individuals with strongyle FEC of 200epg or greater facilitates a reduction in selection pressure for anthelmintic resistance. Moreover, the results show that such a strategy has a high chance of reducing the financial cost compared with that associated with more traditional interval treatment regimens, and horse owners should, therefore, be discouraged from the view that it is cheaper to treat all horses prophylactically over time.”

Read more: equinescienceupdate.com

Emergency ventilation system developed

Respiratory or cardiovascular arrest in outdoor animals poses a huge challenge to veterinarians. Ventilation equipment is generally hard to operate and requires electricity and compressed air, and is not easily transportable. 

Anaesthesiologists at the University of Veterinary Medicine, Vienna (Vetmeduni Vienna) have developed an inexpensive device that can be used to ventilate large animals. They report that it is easy to transport and can save animal lives in emergencies.

In work recently published in  Equine Veterinary Education, the scientists confirm that their emergency ventilator is effective in horses. 

Yves Moens is Head of the Vetmeduni’s Clinical Unit of Anaesthesiology and Perioperative Intensive Care Medicine. He and his colleagues have long been concerned by the number of horses that die avoidable deaths because of the lack of a suitable ventilation device. The device they designed is similar to the bellows used to inflate air mattresses but has been adapted by the addition of a manually operated expiratory valve.

Although it can only provide 2.5 litres of air, the researchers believed that it would provide sufficient ventilation if the bellows were activated several times in quick succession. They tested this idea on five anaesthetised Haflinger horses during castration surgery and showed that gradual ventilation with the 2.5 litre pump was sufficient to keep the animals alive.

 “It improves the safety of large animals in the field, both during routine anaesthesia and in emergencies. It will also help veterinarians to provide emergency first aid in these circumstances and respect the guidelines for good practice", says Moens. “The respiratory pump is inexpensive and easy to use and will help veterinarians treat their patients in the field.”

Read more : equinescienceupdate.com

How accurate is thermography of horses’ legs?

Infrared thermography is increasingly being applied to investigate the cause of lameness in horses.  The equipment is easy to handle and the method is fast and safe, both for the animal and for the vet.  But is it accurate? 

Recent work by Simone Westermann at the University of Veterinary Medicine, Vienna shows that the technique is surprisingly tolerant of variation in the position of the equipment, i.e. how far from the horse and at what angle to the animal the infrared camera is held. 

In fact, the results were almost completely unaffected by 20° changes in camera angle and increases of up to 50 cm in the distance of the camera from the animal.  At a distance of 1m from the horse a 20° change in camera angle corresponds to about 35 cm.  This represents the effective horizontal tolerance in positioning of the camera.  As Westermann says, “vets should have little difficulty in remaining within this limit, so the method is applicable in practice”. 

Surprisingly, the results showed that horses’ left and right forelimbs show minor differences in temperature and Westermann cautions that “it might be important to take these into account before reaching a final diagnosis.”

The technique is thus reliable and robust, at least in terms of variation in where the camera is located. 

However, it turned out to be extremely sensitive to even very gentle drafts.  A wind speed of less than 1 m/s causes a drop in measured temperature of about 0.6°C, while winds of 1.3-2.6 m/s cause a drop of 1.5°C and winds of 3-4 m/s cause a drop of 2.1°C.  The discrepancies are more than sufficient to lead to a wrong diagnosis, although even the highest wind speed tested is hardly perceptible:  it would barely cause leaves on trees to move.

Westermann is keen to note the relevance of her work for vets who work on horses.  As she says, “It turns out that it is not too important to be sure that the camera is in exactly the correct position before taking measurements.  But it is essential to perform thermography on horses in a room that is completely free of draughts.  If you don’t, your diagnosis will be completely unreliable.”

More information : equinescienceupdate.com

Antibacterial action of honey

Wounds to the lower limbs of horses can prove challenging to manage.  Recently there has been a growing interest in the use of honey in such cases.

Not all honey is the same. Its antibacterial quality depends on the type of honey and the conditions under which it was harvested and processed. Most honey contains hydrogen peroxide, which has antibacterial properties. Some types of honey contain other active components. For example, manuka honey is believed to have antibacterial properties due to high concentrations of methylglyoxal, a compound usually found in only low quantities in other types of honey.

Manuka honey, produced by bees foraging on manuka plants (Leptospermum scoparium), native to Australia and New Zealand, has been the subject of considerable research. Honey from other sources is often used in practice, but there has been little research into how effective it is.

Researchers at the University of Glasgow have been examining various different types of shop-bought honey to determine if they were free from bacterial contamination and suitable for use on equine wounds. They also investigated the effect of various examples of uncontaminated honey on the growth of equine pathogens, and  found that, in laboratory tests, certain varieties of honey are able to inhibit bacterial growth even at very low concentrations.

They found that many commercial sources of honey were contaminated with bacteria. The most commonly identified contaminating organism was Bacillus spp. However, potentially pathogenic organisms  (Proteus and Enterobacteraceae) were identifed in two honey samples.

Uncontaminated honey samples were subjected to further investigation to assess their antibacterial properties. Eight of the eleven samples tested were effective against all 10 bacterial isolates at concentrations from 4 to 16%. Overall, medical grade Manuka honey and a locally produced heather honey performed best.

The researchers conclude that many honeys have antimicrobial properties, and may be effective in the treatment of wound infections. They note that the concentrations at which honey samples inhibited microbial growth were much lower than is likely to occur at the surface of an infected wound treated with honey.

However, they advise that “the use of shop-bought honey on wounds should be avoided, as contamination with potentially pathogenic microbes appears to be common. Honey sourced within the UK is as, and in some cases more, effective than medical grade honey sourced in New Zealand.”




Read more at equinescienceupdate.com/articles/aah.html

New laminitis research findings

Laminitis continues to be a significant welfare problem of horses and ponies, causing widespread suffering. Investigations into the underlying causes and disease processes involved in the condition are ongoing.

The benefits of  feeding a balanced diet alongside appropriate forage, grazing restriction and regular low intensity exercise whenever clinically possible in the management of laminitis prone horses and ponies have been highlighted by new research.

Four separate studies have shed new light on the possible role of grass fructan in the development of laminitis; the influence of water temperature when soaking hay to reduce the water-soluble carbohydrate content; a possible link between recurrent laminitis and reduced anti-inflammatory capacity, and the potential anti-inflammatory benefits of exercise.

Read more at equinescienceupdate.com

Controlling forage intake with hay nets

Horses have evolved to spend much of the day grazing. However, modern systems of horse management often restrict the time available. This may contribute to problems such as gastric ulceration and can result in behavioural problems.

Sometimes it is desirable to reduce the intake of roughage – either to make the horse's ration last longer, or to limit its overall intake.

Recent research from the University of Minnesota shows that using hay nets with smaller holes is effective for limiting the rate of roughage ingestion in horses.

Eight horse were involved in the study. They were were housed in individual box stalls, and fed hay off the floor (control treatment) or from hay nets with one of three different sized holes. The mesh size ranged from 15.2cm (large), to 4.4cm (medium) and 3.2cm (small).

During the trial period, hay was available for two four-hour periods each day.

Horses were allowed to become accustomed to each type of net for 2 days, before intake was recorded over three days. They then had two days of a wash out period during which they were as a group in an outdoor paddock.

The researchers found a significant difference in the rate of consumption between all treatment groups. Horses fed hay off the floor (control) consumed hay at the rate of 1.49kg/hr. Consumption of hay from hay nets was 1.33kg/hr, 1.11kg/hr, 0.88kg/hr for large, medium and small sized holes respectively.

They found no difference between the large mesh net and control for the amount of hay consumed (both 95%% of hay offered); but medium and small hay nets restricted hay intake to 89% and 72% respectively.

They conclude that their results demonstrate that the medium and small sized nets were effective in decreasing both rate and amount of forage consumed by adult horses.





More information at equinescienceupdate.com

Geldings behaving badly

Some horses display stallion-like behaviour despite appearing to have been castrated. Before embarking on exploratory abdominal surgery, how do you distinguish between those with a retained testis (cryptorchid or “rig”) and those that just behave badly?

One technique is to assess resting serum testosterone concentrations to identify horses with functioning testicular tissue.

Recently published research suggests that testosterone levels vary through the year and that this should be borne in mind when interpreting the results. Apparently, spring is the best time to use a serum testosterone assay to confirm the presence of a suspected retained testicle.

Researchers at the Gluck Equine Center, University of Kentucky, and the University of California Davis (UCD), examined data from blood samples submitted from suspected cryptorchids to the clinical endocrinology laboratory at UCD.

Serum from 179  suspected cryptorchids with serum testosterone greater than 100pg/ml were included in the study. In the UCD laboratory, testosterone levels lower than 50pg/ml are interpreted as evidence of absence of testicular tissue, while levels >100pg/ml confirm the presence of testicular tissue.

The research team found that serum testosterone concentration varied with season, being higher in spring than at other times of the year and lower in fall compared with summer and winter. Concentrations of testosterone reached a peak in May and were lowest in November.

They also noticed a significant association between age and testosterone concentration – with testosterone levels  being lower in cryptorchids less than two years old. Testosterone levels also declined  in horses older than nine years old.

They advise that borderline low testosterone concentrations found late in the year might still be positive – so a further test should be performed the following spring if the animal continues to display stallion-like behaviour.

Horsecare smartphone app released

US veterinarian Doug Thal has developed a new smartphone app to help horse owners with equine health matters.

The aim of the app is not to replace the owner's veterinarian, but rather to improve the quality of communication between horse owner and vet, for the benefit of the horse, he says.

Dr. Thal believes that horses receive the best care from well-educated owners that have a strong relationship with their veterinarian. “In fact, good communication with your veterinarian at the onset of equine healthcare problems will likely give you more options, cost you less in the long run, and enable you to do the best by your horse“.

Horse owners are increasingly turning to the internet for information about horse health, he says. Sometimes they do so instead of calling the veterinarian. Too often this approach results in inappropriate or delayed treatment, and may eventually cost more.

Dr Thal, an equine veterinarian for 20 years, states that the Horse Side Vet Guide™ (HSVG) provides easy access to essential equine healthcare information, powered by a constantly growing knowledge base. “The idea that a horse owner could make an observation and immediately access credible information about that observation- literally “horse side” – is the driving concept behind this product”.

All the text records in HSVG  are downloaded to the phone, and so are available at any time, even without access to the internet. Videos, providing short demonstrations of skills that might be needed in an emergency, as well as anatomy images and tables of normal values, are also stored in the quick reference section. However, in order to keep the size of the app reasonable, access to many other videos, media, and outside resources do require an internet connection.

Horse Side Vet Guide is currently available for iPhone and costs $4.99.  An Android version is being developed.

Further details are available from: http://horsesidevetguide.com/

Australian search for anthelmintic plants

Scientists in Western Australia have been investigating the anthelmintic effect of various plant extracts. In a laboratory investigation, they screened extracts of 37 plants to see if they inhibited the development of cyathostome eggs. The results have been published in the journal Veterinary Parasitology.

Extracts from seven species completely inhibited larval development. A further ten species  resulted in 90% inhibition compared with controls.

The research team then took the seven most effective plants extracts and tested how their inhibitory effects were affected by diluting them. The most effective plants,  Alectryon oleifolius and Duboisia hopwoodii, had IC50 (concentration that resulted in a 50% inhibition of development) of 47.2μg/ml and 30.9 μg/ml respectively. In comparison, ivermectin had an IC50 of 0.0000817μg/ml - considerably more effective.

Further tests showed that the effective constituents of many of the plant extracts were likely to be tannins. Tannins may limit palatability, so plants whose anthelmintic  properties rely on them may not be ideal candidates.

However, the researchers identified two plants, Acacia melanoxylon and Duboisia hopwoodii, with anthelmintic properties that were not reliant on tannins.

A further consideration was that the plants may contain other constituents with possible adverse effects.  For example,  D hopwoodii, the most effective plant tested in this study, contains alkaloids such as nicotine and nornicotine, which are toxic for animals.

The search for plants with anthelmintic properties for use in horses is still in the early stages. This study looked at the effect on larval stages, while any anthelmintic would have to be effective against adult worms. Further work also needs doing to identify the active    constituents of the plant that are responsible for the anthelmintic effect.

Eventually, it may be possible to isolate and concentrate the active compound. The researchers calculated that a daily intake of 120g of the anthelmintic plants would expose parasitic worms in the horse's colon to concentrations of 1400 μg/ml – the concentration used in the initial screening test. So it would be feasible exert control over the helminth population by grazing pasture containing the plant or including it in the diet as a feed additive.

They conclude: this study “suggests that Australian plants may be useful in forming part of an integrated parasite management program for horses, but more studies are needed before developing appropriate applications.”

www.equinescienceupdate.com

Road safety: does bright clothing help?

Wearing lights when out riding on roads could be safer than wearing reflective or fluorescent clothing according to research presented at the International Society of Equitation Science annual conference, July 2013.

Rose Scofield, from Duchy College, Cornwall, UK conducted a questionnaire-based study to investigate the value of bright reflective clothing in reducing the risk of ”near misses” between horses and vehicles.

She distributed questionaires through equine websites and forums, receiving 426 replies. Participants answered questions regarding the fluorescent or reflective equipment they and their horses were wearing, and whether they had been involved in near miss incidents.

Scofield grouped the responses according to whether the respondents had experienced a “near miss” with traffic or not. Then she examined whether or not they had been wearing reflective and /or fluorescent clothing.

Most riders who responded to the questionnaire did use some reflective equipment or clothing when riding on the road.

However, when she analysed the data, what she found was perhaps surprising. Reflective clothing, worn either by the rider or the horse, appeared to have no significant effect on the likelihood of a “near miss”.

60% of riders reported a near miss. But the proportion wearing reflective clothing on either the horse or rider was similar to that of those who did not experience a near miss.

However, significantly fewer near misses were reported by riders wearing lights.Of all the riders, 8.2% wore lights and did not experience a near miss, whereas 3.6% had a near miss despite wearing lights.

“This suggests that wearing lights should possibly be recommended when riding on the roads to enhance the safety of both rider and horse and contribute to the welfare of the leisure horse in particular.” 

“The use of lights by a rider and horse combination may prove a sound contribution to the welfare of the leisure horse in avoiding possible road accidents.”

For more details see:
Road safety: is there a relationship between ‘near misses’ and the use of rider and horse reflective/fluorescent equipment?
Rose M. Scofield, Hannah Savin, and Hayley Randle,
Proceedings of the International Society of Equitation Science (2013) p30

Does whip use improve show jumping performance?

Researchers in the UK have turned their attention to the use of the whip in show jumping, to see whether it is associated with improved performance.

Catherine Watkins of Hartsbury College in Gloucester presented the results of the study at the 2013 International Society for Equitation Science (ISES) conference.

Whips are carried and used in competition by show jumpers at both the non-elite and elite levels. The study  showed that non-elite show jumping riders were more likely than elite riders to carry a whip. It also showed that increased use of the whip did not increase the chance of finishing with a clear show jumping round. In fact, when the whip was used, the horse was less likely to complete a clear round.

The researchers observed 229 non-elite and 229 elite show jumpers at affiliated UK show jumping competitions.

Non-elite riders were found more likely (69%) to carry a whip than elite riders (62%). Faults were 1.3 times more likely to occur for those riders who carried a whip. The likelihood of achieving a clear round decreased for riders who used the whip, with riders who carried but did not use a whip faring better. Elite riders who carried the whip but did not use it fared the best.

In addition to calculating the likelihood of achieving faults or clear rounds, the researchers compared active use of the whip with current British Show Jumping rules, which state that: misuse or excessive use will not be tolerated; the whip should not be used more than three times after entering the arena; the whip cannot be used prior to commencement of the course; and the whip is only used if the rider removes a hand from the reins.

In spite of these rules, Ms Watkins and her research partner observed seeing “a fair amount of misuse or excessive use of the whip in the arena” “The study found a total of 38 cases where the whip was used either as a punishment tool, or was not presented at the fence.” Of all the show jumping riders observed, none was reprimanded for misuse of the whip or rule infraction.

Of the 458 rounds observed, “Overall 65.5% of riders carried a whip…and 20.7% of those who carried a whip used a whip. Non-elite riders were more than twice as likely to use the whip.”
The researchers speculated that knowledge and experience level reduced the likelihood of the whip being used.  An alternative explanation is that elite riders are on higher quality, more athletic horses that simply don’t have as much “need” for the whip.

This information may be of value to both show jumping organizations reviewing position statements on whip use and equestrians competing in shows. “Those who used the whip were statistically less likely to achieve a clear round…elite riders were statistically more likely to achieve faults if the whip was used.” states Watkins.

With an increase in public awareness of welfare in equestrian sport, discussion of the rules governing whip use is gaining momentum. As evidence is emerging from other equestrian disciplines there is clearly a need for continuing review of whip use. The researchers hope that their study will help stimulate the debate.

For more details see:
Evaluation of whip use and prevalence in elite and non-elite show jumpers.
Catherine Watkins and Darcy Murphy.
Proceedings International Society for Equitation Science (2013) p54

700,000 year old horse DNA sequenced

Researchers have constructed the DNA from a 700,000 year old horse fossil from the far north west of Canada, which has challenged the accepted version of equine evolution.

Indeed, the widely accepted understanding of the horse's evolution is of a gradual increase in size from small forest-dwelling animals to the larger animals of today.

The fossil, found in the Klondike area of Yukon by  University of Alberta researcher Duane Froese, raised questions about this version of events. Not only was the  fossil considerably older than those commonly found in ice age deposits in the Yukon, Alaska and Siberia, it was also at least as large as many modern horses.

The layer of permafrost in which the fossil was found has been dated  by the volcanic ashes it contained as originating about 700,000 years ago. This puts it among the oldest known ice in the northern hemisphere.

An international research team, led by Ludovic Orlando, and colleagues at the University of Copenhagen, Denmark, managed to extract fragments of ancient DNA from the fossil. After several years work, they succeeded in constructing  a draft genome of the horse. This is by far the earliest genome sequence yet recorded. “Our data represent the oldest full genome sequence determined so far by almost an order of magnitude” they say in the report of their work, which is published in the journal Nature.

It is unlikely that the research would have been successful had the DNA not remained frozen over the past 700,000 years.

Having reconstructed the complete genome of the horse, the team compared it with DNA from a horse dating from the Late Pleistocene (about 43,000 years ago), and from five contemporary domestic horse breeds, a Przewalski's horse and a donkey.

By looking at differences between the DNA of the various horses, they could estimate the rate at which mutations occurred in the genetic code over time.

Analysis of differences between these genomes indicated the last common ancestor of all modern equids ( horses, zebras and donkeys ) would have lived about 4.0- 4.5 million years ago. This is about twice as far back than previously thought.

The results also indicated that Przewalski’s horse― an endangered subspecies native to the Mongolian steppes ― diverged from the lineage that gave rise to modern domesticated horses about 50,000 years ago.


More information at: equinescienceupdate.com

Genetics and tendon injury

Superficial digital flexor (SDF) tendon injury is a common cause of wastage in National Hunt Thoroughbred (TB) horses – leading to training and racing days lost and early retirement.

Recent research, funded by the Horserace Betting Levy Board, explored whether genetic susceptibility is a potential risk factor for SDF tendon damage in the TB racehorse.

The work, by Lucinda Tully and colleagues, compared the genotype of horses with and without SDF tendinitis in a case-control study.

Tully looked specifically at single nucleotide polymorphisms (SNPs) in seven genes that are involved in tendon structure, function, and remodelling or are known to be involved in Achilles tendinopathy (an equivalent condition in humans).

Genetic material for the study was derived from mane hair, or peripheral blood cells, collected from 270 horses with a history of SDFT strain, and 270 unaffected control samples, chosen at random from among the other horses on yards with affected cases.

The study's findings suggest that sequence variants in TNC and COL5A1 genes are associated with SDF tendinopathy in TB racehorses.

A SNP in COL5A1 significantly increased the odds of having SDF tendinitis. Racehorses having two copies of the COL5A1 COL5A1_01 variant allele were nearly 3 times more likely to have SDF tendinopathy than those homozygous for the wild-type allele.

Conversely , a SNP in the TNC gene was associated with significantly lower odds of SDFT injury. Racehorses heterozygous for the TNC BIEC2-696469 polymorphism were less likely to have SDF tendinopathy than those with two copies of the wild-type allele.

The research team conclude that variants in the TNC and COL5A1 genes are associated with SDF tendinopathy in a population of UK trained NH TB racehorses.

They suggest that further studies in a larger group of horses are needed to determine the significance of these findings at the population level.

In the future it may be possible to use genetic markers to identify horses at risk of SDF tendinopathy.

Read more: www.equinescienceupdate.com

Fishing for chips

Not only is chipping far more reliable for marking horses than traditional methods of branding, it also causes far less injury to the animals, according to research led by Christine Aurich at the University of Veterinary Medicine, Vienna.

With very few exceptions, it is now mandatory within the European Union to mark horses by means of transponders. Nevertheless, some sport-horse registries oppose the use of microchips because they believe that the rate of identification failure is unacceptably high.

Thus far, no systematic examinations to see whether chips are easy to decode, have been conducted. So Manuela Wulf in the group of Christine Aurich at the Vetmeduni Vienna has examined the readability of microchips in more than 400 horses. She tested each of the chips with three different scanners. The scanners differed in diameter and field strength. Both sides of the animals’ necks were tested.

The “best” scanner (equipped with a digital signal processing function that filters interfering signals) detected and read all chips correctly when it was placed on the side of the neck where the chip was implanted, and located nearly 90% of the chips even when it was on the other side of the neck. The other two scanners performed considerably less well, producing correct reads in around 90% of the cases when on the same side of the neck. On the opposite side of the neck, however, the success rate fell to between 20-25%.

It never took more than 25s to detect the microchip , and with the most effective scanner it took a maximum of 5 seconds. So the most effective scanner not only detected all the microchips , it did so in the shortest time.

As Wulf puts it, “It is important that the scanners find and read the chips correctly in every case. We can only recommend the top-of-the-range scanner, which should ideally be placed on the side of the horse’s neck where the chip was implanted.” However, Aurich adds, “Even the lowest quality scanner we tested, performed much better than traditional branding methods of horse identification.”

The major objection to the use of branding relates to the pain and long-term damage it inflicts on the animals. Wulf and her colleagues thus investigated whether the use of microchip markers was any better. She looked closely at the site of chip implantation in 16 horses of nine different breeds and of various ages that had been submitted to the Vetmeduni for post mortem examinations. In the vast majority of cases, the chips seemed to have caused absolutely no ill effects. Two animals that were moderately affected had probably only been chipped recently and the wound had not yet had time to heal.

Aurich sums up the findings, “Not only is chipping a far more reliable method for marking horses than traditional methods of branding, we also found that it causes far less injury to the animals.”

More information: equinescienceupdate.com

Does the human voice calm horses?

In addition to being warned to move slowly around horses, many new riders are also instructed to speak in a soothing tone, in the belief that it can make the animal calm. A recent study presented at the 2013 conference of the International Society for Equitation Science investigated whether such advice actually had a beneficial impact on the horse.

According to Katrina Merkies of the University of Guelph, “Anecdotally, we know that horses respond better to calm and soothing tones, so our hypothesis is that speaking in a calm and pleasant voice will inspire calm behaviour in a horse.”

Merkies and other researchers from both the University of Guelph, Ontario, Canada and Agrocampus Rennes, Rennes, France set out to discover whether emotional tone and pitch of voice did have any effect on horses. For the study, eight draft horses were individually assessed in a 10 m round pen. Each horse was released into the pen, and baseline behaviour and heart rate (HR) readings were taken over a five minute period. Behaviours scored included: gait; head height position; ear and body position relative to the human.

After establishing baselines, a familiar human approached the pen, and one of four recorded voices was played for a 10 second duration: PL – pleasant voice low tone; PH – pleasant voice high tone; SL – stern voice low tone; SH – stern voice high tone.

Researchers found that the horses maintained the lowest head position when no human or sound was present, but all elevated their heads in the presence of a human or sound. The playing of a pleasant tone resulted in the horses positioning their bodies toward the human. While there was no treatment effect on ear position, the horses did orientate their ears more toward the sound if the human was present.

Horse HR did not increase solely in the presence of the human, but it did increase coupled with sound, with SL in particular resulting in the greatest effect. Results would indicate that fewer signs of behavioural distress are observed when a human speaks to the horse in a pleasant, low tone rather than a stern tone.

“We’ve shown that horses do in fact display different physiological and behavioural responses to different tones and voice. So horses are able to discriminate between different tones or qualities of voice.”

Research often creates more questions than it answers, and based on the results obtained, additional research may be required: “However, it’s not clear if the horse is interpreting or responding to the tone of voice alone, or if it’s looked at in combination - both tone of voice and the human’s body language. Which is the more salient clue to the horse? That certainly warrants further study.”

Improving management of wild horses and burros

How to manage the feral horses and burros of the western United States has been the subject of heated debate for some time.

A recent scientific review found that the current practice of removing free-ranging horses is counter-productive. The review concluded that the current approach promotes a high population growth rate, and that maintaining horses in long-term holding facilities is both economically unsustainable and contrary to public expectations.

Most free-ranging horse populations are growing at 15 percent to 20 percent a year, meaning these populations could double in four years and triple in six years.

“With no intervention by BLM (the U.S. Bureau of Land Management), the horse population will increase to the point of self-limitation, where both degradation of the land and high rates of horse mortality will occur due to inadequate forage and water. In addition, periodic droughts, many of them severe, in the western public lands cause immediate and often unpredicted impacts.”

The report noted that there is little, if any, public support for allowing such harm to come to either the horse population or the land itself. However, the current removal strategy used by BLM actually perpetuates the overpopulation problem by maintaining the number of animals at levels below the carrying capacity of the land. Although this protects the rangeland and the horse population in the short term, it results in continually high population growth and exacerbates the long-term problem.

To manage horse populations without periodic removals, the committee concluded that widespread and consistent application of fertility control would be required.

Here's a video in which Committee chair Dr. Guy Palmer of Washington State University shares key findings about using science to improve the BLM wild horse and burro program.

The full report is available online.

http://www.nap.edu/catalog.php?record_id=13511