Urine DNA profiling

Scientists will soon be able to use DNA profiling techniques to confirm the identity of racehorses that have tested positive to drugs.

Such a test would dispel any doubt about sample substitution and confirm that a sample did in fact come from a particular horse, helping to either confirm the identity of horses returning positive drug samples, or exonerating horse and trainer.

The report “DNA Profiling of Horse Urine Samples to Confirm Donor Identity” resulted from studies carried out by Paula Hawthorne and colleagues at the University of Queensland, and was funded by the Australian Government's Rural Industries Research and Development Corporation (RIRDC). The research team tested various techniques for DNA profiling on seven urine samples and compared the results with those from hair samples taken from the same horses.

They found that storage time and temperature had a significant effect on the success of the DNA profiling. Urine could be stored at 4°C for no more than two days (or frozen at -20°C or -80°C) before processing. Samples stored at 4°C for a week or more yielded no profiles.

The most successful technique, a commercially available test, allowed them to identify all twelve microsatellites, in four urine samples - all from male animals. As only seven samples were examined overall, it was not possible to tell whether that was a coincidence, or whether it really is more difficult to extract DNA from mare’s urine.

All DNA profiles from the urine samples matched those from the hair taken from the same horses.

There is still more work to do - for example, the researchers point out that drugs in the urine may interfere with DNA profiling. So once the best method of DNA profiling has been established, further tests will be required to assess whether the results are affected by drugs likely to be found in the urine.

However, the authors of the report suggest that once the optimum method has been finalised it should not take long to integrate it into existing procedures of racing drug-testing laboratories.

The full report is available for purchase or free download. See:
https://rirdc.infoservices.com.au/items/09-076

Risk of Atypical Myopathy cases this spring.

“There seems to be an increased risk of cases of Atypical Myopathy during the spring, when the disease has occurred during the previous fall” warns Dr Domonique Votion, of the University of Liege.

In the last few months of 2009, Western Europe experienced the largest ever series of cases of the disease, according to the Atypical Myopathy Alert Group (AMAG).

No less than 371 cases were notified to the AMAG. Of those horses, 265 died, giving a survival rate of just 22%. Most cases were reported in France (124) Germany (92), and Belgium (64).
Thirty-five cases were identified in the UK.

Horses with Atypical Myopathy suffer from severe, generalised weakness. They are often unable to get to their feet, or only do so with difficulty. If they are still able to walk, they do so with a stiff gait - especially of the hindquarters. Muscle tremors and generalised or patchy sweating may be seen.

Affected animals have elevated heart rates. They often have increased respiratory rates, with difficulty on expiration. The rectal temperature is usually below normal. Dark brown colouration of the urine is characteristic.

Despite the severity of the signs, horses often still seem keen to eat and will try to grasp hay that is held close to their mouth.

Often the first sign of disease is stiffness, especially of the hindquarters. However, it is not unusual for severely affected cases to be found dead on the pasture with no previous sign of illness.

For more details about the Atypical Myopathy and the Atypical Myopathy Alert Group see:

http://www.myopathieatypique.be

Disease surveillance report

The latest equine disease surveillance report published jointly by the UK Government’s Department for environment food and rural affairs (Defra), Animal Health Trust (AHT) and the British Equine Veterinary Association (BEVA), is now available. The report covering the period October - December 2009 has been uploaded recently to the Animal Health Trust website.

The Defra/AHT/BEVA equine quarterly disease surveillance report collates equine disease data arising from multiple diagnostic laboratories and veterinary practices throughout the United Kingdom. The current edition includes data from 30 laboratories and offers a unique insight into equine disease occurrence in the UK.

A form is available on the AHT website for registration to receive reports free of charge, via e-mail, on a quarterly basis.

See:

http://www.aht.org.uk/equine_disease.html

EMS research: help needed

Do you have a horse or pony with Equine Metabolic Syndrome? If so, scientists at the University of Minnesota's Equine Genetics and Genomics Laboratory would like to hear from you.

EMS is characterized by three main features: obesity or regional accumulation of fat (particularly in the crest or over the rump), insulin resistance and laminitis.

Some horses, often considered to be "easy keepers" by their owners, are more at risk of EMS than others. It is likely that the genetic make-up of the horse affects its susceptibility to the condition.

The aim of the study is to better understand the role in EMS of factors such as breed, gender, age, environment (diet and exercise) and genetics. To achieve this, the researchers need to collect data from as many horses with EMS as possible. So, they are keen to encourage horse owners and their veterinarians to get involved.

If you are interested in taking part in the Equine Metabolic Syndrome research project, the first step is to complete a short online survey. Within about one month, if your horse is considered suitable for the project, you will be asked to complete a second survey. This will ask for further information about the horse and about another horse, unaffected by EMS, that lives on the same property. This horse will serve as a "control". Ideally the control horse should be of similar breed and age, have no history of laminitis, not be overweight and show no signs of Cushing's syndrome (delayed shedding, increased drinking/urination).

The third step is to submit a blood sample to the laboratory, for biochemical analysis and DNA evaluation.

To identify the underlying genetic susceptibility to EMS, the scientists will compare genetic markers between horses with and without EMS. The genetic differences that are highly correlated to having EMS can be used as genetic markers for the disease.

The long-term goal is to use these EMS genetic markers to detect horses susceptible to EMS and laminitis before they have clinical signs. It may then be possible to change the management of susceptible animals to reduce the risk of them developing disease.


For more details about the study

http://www.cvm.umn.edu/equinegenetics/ems/research/index.htm

Rapid ringworm diagnosis

Scientists in South Korea have described a rapid method for diagnosing ringworm (dermatophytosis.)

Fungal culture is the “gold standard” method for identifying the species of dermatophyte involved, based on the colony characteristics and microscopic appearance. It is accurate but time consuming. Samples may have to be cultured for up to three weeks before the organism can be identified.

It’s not necessary to know the species before starting treatment. Indeed, to prevent the spread of infection, treatment is usually started pending the results of laboratory investigations.

However, there are occasions when it may be useful to know the identity of the dermatophyte involved, as it may help to identify the source of the outbreak. For example Trichophyton mentagrophytes can be found in soil and be carried by rodents.

Researchers at the Colleges of Veterinary Medicine at Seoul National University and Konkuk University compared a rapid molecular PCR assay with conventional fungal culture for diagnosing ringworm.

They found that the PCR analysis of the fungal DNA was superior to traditional fungal culture for diagnosing dermatophyte infection, “ in terms of sensitivity, specificity and particularly rapidity.”

Read more at www.equinescienceupdate.co.uk/rmmdd.htm

Exercise and pregnant mares

In humans, moderate exercise in pregnancy seems to do no harm and may help limit excessive weight gain and maintain fitness for the birth. What about horses? Many pregnant mares are ridden and subject to moderate training up to the later stages of pregnancy.

A research team from the University of Maine and the Equine Science Center, Rutgers University, New Jersey compared the response of pregnant and non-pregnant mares to a graded exercise test.

Six unfit standardbred mares were assessed when nine months pregnant and again eight months later after weaning. The exercise test was carried out on a treadmill inclined at 6%. The speed increased in steps of one minute each at 4m/s, 6m/s and 7m/s.

At each stage of the graduated exercise test, mares had lower heart rates when pregnant than after weaning. Plasma lactate concentrations rose less in response to exercise when mares were pregnant than when they were not. The researchers speculate that this might be due to greater cardiovascular efficiency during pregnancy.

Resting plasma cortisol levels were lower during pregnancy than when the mares were not pregnant.

When exercised, pregnant mares showed no increase in cortisol levels. In contrast, when they were not in-foal, the mares showed a normal increase in plasma cortisol during and after the exercise test.

Neither did exercise have an effect on foetal heart rate. This suggests that the unborn foal is not stressed by the mare undertaking moderate exercise.

The researchers conclude: “these data suggest that pregnant mares benefit from greater cardiovascular efficiency during pregnancy. They should be able to perform limited moderate exercise without any major deleterious effects on their unborn foals or themselves during late gestation.”


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Tick-borne disease in Danish horses

Tick-borne infections are common in Danish horses. A survey published in Acta Veterinaria Scandinavica showed that many Danish horses carry antibodies to Borrelia burgdorferi sensu lato (the group of Borrelia species known to cause Lyme disease) and Anaplasma phagocytophilium (the cause of equine granulocytic anaplasmosis).

The study, overseen by Dr Anders M Bojesen of the Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Denmark aimed to evaluate the seroprevalence of B. burgdorferi s. l. and A. phagocytophilium in Danish horses.

Overall, 29.0% horses were seropositive for B. burgdorferi s. l. and 22.3% were seropositive for A. phagocytophilium. This was a higher proportion than had been found in previous studies in neighbouring countries.

There was no significant correlation between risk factors investigated, including breed, gender, age, use and housing and the occurrence of antibodies against B. burgdorferi s. l.

However the researchers did find that older horses were more likely to have been infected with A. phagocytophilium. Compared with horses aged between 1-4 years old, those aged 11-20 years were 2.3 times more likely to be seropositive for A. phagocytophilium, and horses over 21 years old were 3.3 times more likely to be seropositive.

Horses seropositive for B. burgdorferi s. l. were likely to be seropositive for A. phagocytophilium and vice versa.

The researchers conclude “these findings warrant further attention to these infections in horses particularly with regard to improved means for detection of active infections, which may contribute to a better understanding of these diseases and their impact on horse behaviour and welfare.”

More details...

New equine respiratory condition described

Danish Researchers have identified a new cause of respiratory disease in horses. They found the bacterium Stenotrophomonas maltophilia in samples collected from horses with chronic lower airway disease.

Stenotrophomonas maltophilia, a Gram-negative bacterium, has been found increasingly in human medicine, especially in patients with impaired immune systems. Until recently the organism has been recorded only rarely in animals.

In a paper to be published in The Veterinary Journal, Lotte Winther, a PhD student in the Department of Large Animal Sciences at the University of Copenhagen, and colleagues present data from seven horses with respiratory disease associated with S. maltophilia infection.

All cases had a history of chronic coughing. Endoscopic examination revealed copious mucopurulent exudate in the lower trachea. Culture of the tracheal exudate produced grey, slow-growing colonies, which were identified as S. maltophilia by both culture and DNA testing.

Many antibiotics commonly used to treat equine respiratory infections were not effective against S. maltophilia.

The findings suggest that S. maltophilia can act as a respiratory pathogen. The researchers advise that the organism be included in the differential diagnosis of horses with respiratory disease associated with copious mucopurulent exudate.

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TEST TO PREVENT UNNECESSARY FOAL DEATHS LAUNCHED

A new diagnostic test, which gives breeders the ability to eradicate Foal Immunodeficiency Syndrome, was launched on 1 February by UK scientists.

Foal Immunodeficiency Syndrome (FIS), a genetic disorder which is known to affect Fell and Dales ponies, causes foals to become anaemic and prone to opportunistic infections. Sadly, any foal born with the syndrome will not survive.

The DNA test, which costs £40, will not only identify foals which have the fatal condition but will highlight adult ponies who are carriers of the genetic trait which causes the syndrome. Affected foals will be prevented by avoiding breeding a carrier mare with a carrier stallion.

Owners and breeders who wish to find out the genetic status of their ponies can arrange for a simple pulled mane or tail hair sample to be taken by a vet and submitted to the Animal Health Trust. The Fell Pony or Dales Pony Societies will supply sample bags for submission on request.

Dr. June Swinburne of the AHT, who led the research team, said: “The DNA test gives owners and breeders the power to overcome this devastating illness. It enables them to make informed decisions about which ponies to breed. We have already had samples submitted by HM The Queen from her own breeding stock of Fell ponies. I’d urge any breeders of Fell or Dales ponies to submit samples in order to arm themselves with the facts they need to prevent the birth of affected foals and thereby avoid this distressing condition.”

For more information on testing, owners should contact the Fell or Dales Pony Societies.
Alternatively visit the AHT website http://www.aht.org.uk/genetics_fis.html or email FIStesting@aht.org.uk

Ivermectin for foal deworming warning

Ivermectin should not be the drug of choice for controlling Parascaris equorum (large roundworm) in foals a recent study warns.

Dr Eva Osterman-Lind and Dr Dan Cristensson of the National Veterinary Institute, Uppsala, Sweden, investigated the occurrence of Parascaris equorum infection on nine stud farms in Sweden and assessed the efficacy of three commonly used dewormers.

They found that ivermectin had very little, or no, effect on the output of ascarid eggs.

“The most striking result from this study was that in five studs out of six, ivermectin failed to suppress the faecal output of P. equorum eggs” Osterman-Lind and Cristensson report in the journal Acta Vet Scandinavica. “Ivermectin resistance is now a widespread problem in Swedish stud farms.”

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How common are wobblers?

Cervical vertebral stenotic myelopathy (CVSM) is an important disease of Thoroughbred horses in which compression of the spinal cord in the neck leads to incoordinated gait. Affected horses are often described as “wobblers”.

But how common is the condition? Researchers at the University of Glasgow studied records from four breeding establishments - three European Thoroughbred stud farms (936 foals) and one farm in USA (353 foals) - over a 7 year period.

During that time there were 13 cases of Type 1 CVSM, (dynamic stenosis); 5 horses with Type 2 CVSM (static stenosis) and 5 horses in which the Type could not be determined. Overall, 1.3% of the animals were found to be affected.

The average age at which signs of the condition became apparent differed. Horses affected with dynamic stenosis were noticed at a younger age than were those with static stenosis. Type 1 (dynamic stenosis) was diagnosed typically in yearlings (Mean 433days old - about 1y 2 months.) Horses affected with the stenotic compression were diagnosed later - (mean 1188d -about 3years 3 months)

The researchers also found that male horses were significantly more likely to be affected (17 male to 6 female), which agreed with previous studies.

“CVSM is an important disease of Thoroughbred horses and leads to wastage in the thoroughbred industry through the inability to race and the loss of affected horses” the report's authors conclude.

They suggest that “further investigations of the prevalence of CVSM in populations of thoroughbreds and other breeds and determination of risk factors for the disease are warranted.”

More details...

Genetic Test for ‘Speed Gene’ in Thoroughbred Horses

Researchers have identified a gene that can predict the type of work that is most appropriate for an individual Thoroughbred racehorse.

The work, led by Dr Emmeline Hill at University College Dublin, was published in the Public Library of Science Journal, PLoS ONE.

The MSTN gene is responsible for muscle mass development. At a specific point in the gene, the code can contain either the letter C or the letter T. As each individual has two copies of the gene—one inherited from the dam, one from the sire—there are three possible combinations of the letters: C:C, C:T or T:T.

The researchers found that C:C horses were suited to fast, short-distance races; C:T horses competed favorably in middle-distance races; and T:T horses had greater stamina.

The findings were independently validated in a re-sampled group of 62 unrelated elite (Group and Listed race winners) Thoroughbreds and in another group of 37 elite racehorses.

Following the success of the research program, Dr Hill and Mr Jim Bolger, the renowned Irish racehorse trainer and breeder, co-founded a company, Equinome, in 2009 to commercialize the test.

Dr Hill says “Using the Equinome Speed Gene test, a world first in equine genetics, it will now be possible to definitively know a horse’s genetic type within weeks of a sample being taken, thus reducing much of the uncertainty that has been typically involved in selection, training and breeding decisions.”

“Racehorse owners and trainers around the world will be able to identify if a horse is ideally suited to racing over short, middle or middle-to-long distances. With this information, they can then optimize their purchasing and training decisions and better target suitable races for their horses. Breeders, stallion managers and bloodstock agents will also be able to use the test to make more precise selection and breeding decisions to maximize the genetic potential and commercial value of their horses.”

Dr Hill will formally launch Equinome and the Equinome Speed Gene test at 2pm on January 29th at the Irish Thoroughbred Breeders Association Expo 2010 in a seminar entitled Cracking the code: The Speed Gene revealed.


Read more at EquineScienceUpdate.co.uk

For more information about Equinome

Oxytocin promotes placental expulsion

Retention of the fetal membranes is a common post-foaling complication. It is of particular concern in heavy draft breeds, which seem especially likely to develop laminitis if expulsion of the membranes is delayed.

A Japanese study, led by Dr Mitsuo Ishii, found that hourly injections of oxytocin after foaling was an effective way of inducing placental expulsion.

"I recommend that for heavy draft mares, 50iu of oxytocin should be administered from one
hour after foaling and continued at one hour intervals until expulsion of the placenta" Dr Ishii says. " We usually don't remove the placenta manually until 8 hours after foaling."

See more details at equinescienceupdate.co.uk

Sarcoid treatment breakthrough

The battle against sarcoids is forging ahead. Researchers in Scotland have succeeded in killing equine sarcoid cells using a technique known as gene silencing. They are now hoping to obtain funding for clinical trials using the new technique, which could result in a more effective, non-toxic treatment for sarcoids.

Sarcoids are the most common type of tumour found in horses. They are caused by infection with the Bovine Papillomavirus (BPV). The response to treatment is variable, and if treatment fails the sarcoids will often come back with a vengeance.

Recent research, funded by The Horse Trust, offers a potential ray of hope for owners of horses affected by sarcoids. The work was published in the journal Virus Research.

The research, led by Professor Lubna Nasir of the University of Glasgow, found that by inhibiting the activity of a particular viral protein within sarcoid cells, the amount of viral DNA in the cells reduced. This led to a reduction in the growth of the sarcoid cells and caused the cell to die by “Programmed cell-death” (PCD). The researchers believe that PCD occurs because the sarcoid cells become reliant on the virus.

"This could potentially be a major breakthrough in the treatment of sarcoids," said Professor Lubna Nasir. "We are now seeking funding to use this technique in clinical trials on horses that have sarcoids."

"One of the challenges with gene silencing is administering it within clinical setting - as you need to get molecules into every cell. As sarcoids are on the surface of a horse, we think administration should be relatively easy - potentially by injecting or applying a cream to the sarcoid," said Professor Nasir. "If we are able to successfully develop this technique it would be a non-toxic and easy to administer treatment for horses affected by this distressing condition."

See www.equinescienceupdate.co.uk for more details.

Treating piroplasmosis

Research brings hope for horses with piroplasmosis. A drug used to treat protozoal infections in cattle has been shown to be effective against one form of the disease in horses when used at relatively high doses.

Piroplasmosis in horses is known to be caused by two blood-borne parasites, Babesia (Theileria) equi and Babesia caballi. The organisms infect the red blood cells and cause fever, anemia and jaundice.

Infected horses may remain carriers of the infection after recovering from the initial signs of disease. Such horses can transmit the disease even though the organisms can no longer be found in blood smears.

Now researchers at the Agricultural Research Service Animal Disease Research Unit in Pullman, Washington, led by Dr Don Knowles, have found that relatively high doses of imidocarb dipropionate are effective for treating horses infected with Babesia caballi.

Read the full story at equinescienceupdate.co.uk

Test for Fell Pony syndrome

Scientists have developed a test for the gene responsible for Foal Immunodeficiency Syndrome (FIS).

FIS is more often known as Fell Pony Syndrome after the breed most commonly affected. However, the disease is not confined to the Fell Pony, and has been reported in the Dales Pony as well.

Affected foals become ill when they are a few weeks old. Signs include loss of condition, diarrhea, coughing and weight loss. As the condition progresses, they develop anemia, immune dysfunction, and wasting.

FIS is always fatal. Affected foals die or are euthanized, usually before reaching three months of age.

Researchers at New market’s Animal Health Trust (AHT) and Liverpool University have announced that a DNA-based test that should be available in February 2010.

Read the full story at equinescienceupdate.co.uk

Does work cause stereotypies?

Does the type of work that horses do make them more or less likely to adopt stereotypic behaviour? Recent studies in France suggest it could do.

Stereotypies are abnormal repetitive behaviours with no apparent function. They are sometimes referred to as stable vices. Examples include wind sucking, crib biting and head tossing.

Researchers at the Université de Rennes 1, led by Dr Martine Hausberger, observed horses’ behaviour and related it to the type of work they performed.

Seventy-six French Saddlebred horses were divided into six groups according to their work: eventing; show jumping; advanced riding school; dressage; high school and voltige (a mixture of acrobatics and gymnastics on horseback.) All horses worked for only one hour a day and spent the remaining 23 hours in their stable.

The proportion of horses in each work group showing stereotypies was similar (between 81-100%). However, different types of work appeared to be associated with different stereotypies.

Dressage and high school horses were most likely to show stereotypic behaviours. Some of them showed more than one abnormal behaviour pattern. They were also more likely to display the more serious abnormalities such as cribbing, wind sucking and head tossing and nodding.

For more details see equinescienceupdate.co.uk/wsbd.htm

Scientists to study effect of exercise on laminitis.

The Laminitis Trust has awarded a grant of £134,425 to the Royal Veterinary College and the Laminitis Consortium to investigate the effects of exercise on horses and ponies that are predisposed to pasture-associated laminitis.

Lead investigator, Dr Menzies-Gow, explains: “This project will in part investigate whether exercise can reduce the level of chronic inflammation in laminitis-prone animals, which may then prove to be a simple and practical way of reducing the risk of future bouts of disease in susceptible animals.”

The grant commences in January 2010 and will run over two years. The Laminitis Consortium will provide regular updates on progress.

See equinescienceupdate.co.uk for more details...

3D study of neck anatomy

Wobbler syndrome (Cervical Vertebral Malformation, CVM) is a common condition of Thoroughbred horses. Affected horses have a characteristic “wobbly” gait, caused by compression of the spinal cord.

In some cases, the signs of Wobbler Syndrome (Cervical Vertebral Malformation, CVM) have been linked to arthritic changes in the cervical articular process joints. These are the joints between adjacent vertebrae in the neck. They can become inflamed, which can result in soft tissue swelling, thickening of the joint capsule and new bone formation. The joints lie close to the spinal cord, so any increase in their size is a cause for concern.

Some “wobblers” have marked bony and soft tissue swelling around the joints. But does an increase in fluid in these joints result in spinal cord compression, even if no other bony of soft tissue changes are present? If so, it might be possible to prevent the disease progressing by detecting and treating the inflammation at an early stage.

Holly Claridge, working at the Royal Veterinary College, conducted a study using Computed Tomography to examine the structure of the horse’s neck. She found that the joints these joints do indeed extend towards, but do not actually touch, the spinal cord.

So, unless soft tissue or bony changes are also present, it seems unlikely that inflammation or swelling of these joints causes spinal cord compression.

More details...

Inner secrets of Rhodococcus equi

Work to understand the genetic structure of Rhodococcus equi may lead to new measures to control disease in foals. Understanding the complex mechanisms used by the bacteria to cause disease may reveal the microbe’s “Achilles heel” that could be targeted by vaccines and drugs.

“Among the virulence factors we have identified, we have found one in particular that we think might be a good target for a vaccine” says Professor Jose Vazquez-Boland of Edinburgh University. Pathogenic strains of the bacteria have long processes or “pili”, with which they attach to the host cells.

“We identified the genes responsible and produced antibodies against them.” These antibodies prevent the bacteria attaching to the cells and so prevent infection getting established. So this would be a good candidate for a vaccine.

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