Autumn rise in Atypical Myopathy cases

Once again, Europe is seeing a seasonal rise in cases of Atypical Myopathy.

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.

The Atypical Myopathy Alert Group was set up to help owners take preventive measures against the disease. The Group reported that by 23rd December 2011, 116 clinical cases compatible with a diagnosis of Atypical Myopathy had been communicated to Liege University, Belgium, and RESPE (Réseau d’Epidémio-Surveillance en Pathologie Équine: Network of epidemiological surveillance on equine diseases) in France.

Help Solve the Mysteries of Laminitis

Horse owners and veterinarians are asked to collaborate with researchers in a new study into pasture- and endocrinopathy-associated laminitis.

Rather than being based on laboratory research, the study is designed to make use of the wealth of information available in naturally occurring cases of laminitis. Research is already underway under the direction of epidemiologist, Noah Cohen, VMD, PhD at the Texas A&M University College of Veterinary Medicine.

Read more at equinescienceupdate.com

Drug combination may limit joint damage

Research at the University of Sydney suggests that a new osteoarthritis drug combination could significantly extend the working life of racing and other performance horses.

Previous studies has evaluated various medications for the treatment of osteoarthritis in horses, but this is one of the first to show a new drug combination has the ability to slow down damage to joints, rather than just alleviate pain.

"Osteoarthritis is a major cause of wastage in athletic horses, with a significant economic impact on the equine industry," said Dr Toby Koenig, surgical resident at the University of Sydney Veterinary Teaching Hospital, Camden, and lead researcher for the study.

"We found a new combination of three commonly used drugs - pentosan polysulphate, glucosamine and hyaluronic acid - can reduce the damage experienced during strenuous exercise," he added.

"Until now the focus has been on minimising pain for horses suffering from osteoarthritis. We think this new drug combination could have significant impact on the way horses are treated, potentially extending careers of horses in racing, dressage and other competitive events."

Read more at equinescienceupdate.com

More help to avoid positive drug tests

More detection times for commonly used drugs have been released by the British Horseracing Authority (BHA).

According to the BHA, the inadvertent carry over of medication following veterinary treatment is the most common reason for a positive drug test on the day of racing.

An important part of the Authority's drive to keep racing free of drugs is the provision of data to help vets decide when medication should be stopped before racing to minimise the risk of a positive drug test.

"We recognise the need to provide trainers and their vets with this important information to allow them to treat their horses but also avoid race day positive tests."

The BHA has recently announced four new Detection Times for commonly used veterinary medicines; the sedative acepromazine, the sedative /analgesic combination detomidine/butorphanol, the anti-inflammatory treatment prednisolone, and the airway treatment salmeterol.


Read more at equinescienceupdate.com

Research into gene therapy for osteoarthritis

Osteoarthritis, or degenerative joint disease, causes pain and suffering to horses and humans alike.
University of Florida researchers are developing a gene therapy for osteoarthritis in horses, in the hope that the technique will be applicable to people as well. The goal is to create a one-time treatment that gives long-term benefits.
The work involves the use of viruses, called adeno-associated viruses, or AAV, to deliver genetic material to the joints of horses, where it would produce a therapeutic protein directly at the site of the disease.
There is no cure for osteoarthritis. Current medications often only produce limited relief, require repeated administration and may interfere with healing. In contrast, this new gene therapy would require a one-time treatment and would not hinder the body’s healing processes.
Research suggests that the pain, joint inflammation and loss of cartilage associated with osteoarthritis are linked to a protein called interleukin-1. A therapeutic gene used to treat the arthritic joints produces a second protein that naturally counteracts the effects of interleukin-1, but that has not yet translated into effective treatments for patients because of difficulty getting high enough concentrations inside affected joints.
The UF researchers are devising a gene therapy approach that would allow continued production of therapeutic protein within the joints, directly at the disease site.
“We hope that this will be at least the first step in a therapy that will benefit both people and animals,” said Patrick Colahan, a board-certified equine surgeon in the University of Florida College of Veterinary Medicine and co-investigator on the study. “It has the potential to help lots of different species, and from a veterinarian’s perspective, that’s what we’d like.”
Read more at equinescienceupdate.com

Foal heat diarrhoea - no treatment best

New research shows that the bacterial population of the foal's digestive tract undergoes major changes within the first two weeks of life. This change seems to be directly responsible for the "foal heat" diarrhoea that is often seen in young foals.

The work, carried out at the University of Veterinary Medicine, Vienna and the Graf Lehndorff Institute for Equine Science, Neustadt, Germany, found that the onset of diarrhoea was unrelated to the mare returning to oestrus after giving birth.
 
Horse-breeders expect most newborn foals to suffer from diarrhoea. Many methods have been suggested to avoid the problem, including supplementing the mothers’ diets with ß-carotene, which is known to be helpful in preventing diarrhoea in young calves.  However, Juliane Kuhl in the group of Christine Aurich at the University of Veterinary Medicine, Vienna has now shown that this food supplement has no real effect on the incidence of diarrhoea in foals.

Kuhl, Aurich and their collaborators examined the bacteria in the faeces of foals and their mothers, as well as the measuring the levels of antibodies (γ-globulins) in the animals’ blood. 

They found little change over time in the nature of bacteria in the mothers’ faeces, although they did observe dramatic differences in the bacteria in the foals’ faeces. 

Foals are born with very low amounts of bacteria in their intestines but are colonized by E. coli within the first day of their lives.  In contrast, the number of foals with Enterococcus remains low until about ten days following birth, after which these bacteria can be detected in most animals.  Other bacteria such as Streptococcus and Staphylococcus arrive between two and four weeks after birth, by which time the foals’ intestinal flora is essentially indistinguishable from that of their mothers.

Interestingly, the researchers found that the changes in the bacterial flora closely parallel the development of diarrhoea. 

They also found that foals with low γ-globulin levels did not develop diarrhoea more often than those with much higher levels. So, the incidence of diarrhoea cannot be related to a weakened immune system.

Kuhl is careful to note that “we have not yet shown that diarrhoea results directly from the switch in intestinal bacteria, although our data make it seem very likely that this is the case.”

The implication is that the horse is essentially predisposed to develop diarrhoea at a very young age.  As the condition clears up fairly quickly without the need for antibiotic treatment, food withdrawal or food supplements such as ß-carotene, breeders should simply accept that many of their animals will suffer from the condition. 

Read more at equinescienceupdate.com

Comparing hot iron branding and microchipping in foals

Research shows that foals find both hot iron branding and microchip implantation stressful, but the effects of microchip implantation do not last as long.

The study, by R Erber and colleagues, compared the response of groups of foals to the two methods of identification..

Fourteen warmblood foals from the Brandenburg State Stud were divided into two groups. Seven foals were branded with a hot iron on the right thigh; the others had a microchip implanted in the neck.

Throughout the procedure the researchers monitored the foals for signs of stress by recording heart rate, and concentration of cortisol in saliva. They also monitored how the foals behaved in response to the procedures.

Both procedures caused stress. Foals showed an increase in heart rate and in saliva cortisol concentration. In fact, foals showed two peaks in heart rate - initially when they were first restrained, and again when the actual identification (branding or microchipping) procedure was carried out.

Although there was no difference in the degree of stress (measured by salivary cortisol and heart rate) between the two procedures, the researchers point out that it was possible that the foals' response to restraint could have masked that due to the procedure itself.

However, the researchers did find a difference between the two procedures. Hot iron branding resulted in skin necrosis that got worse for three days after application. It also produced an increase in skin temperate.

In fact, not only did foals show an increase in skin temperature at the site of the hot iron branding, they had increased skin temperatures on the opposite thigh and on both sides of the neck as well.

So although both procedures appeared to cause similar degrees of stress, hot iron branding produced more persistent changes. It resulted in skin necrosis that lasted for at least seven days. Hot iron branding also resulted in a generalised increase in body temperature that was not seen after microchip implantation.

Read more at equinescienceupdate.com

Seasonal pasture myopathy research

University of Minnesota researchers are seeking the help of horse owners to find out more about Seasonal Pasture Myopathy. This condition, which is frequently fatal, has been identified increasingly in the Midwestern US.

Horses with Seasonal Pasture Myopathy (SPM) suffer from severe, generalised muscle weakness. They are often unable to get to their feet, or only do so with difficulty. If they are still able to walk, they have a stiff gait - especially of the hindquarters. Affected animals have elevated heart rates, and show profuse sweating and muscle twitching. They often have increased respiratory rates. Dark brown colouration of the urine is characteristic. The mortality rate can exceed 90%.

“We have already seen suspected cases of seasonal pasture myopathy this fall in Minnesota and feel it is an under-diagnosed condition in North America,” said lead researcher Dr. Stephanie Valberg of the University of Minnesota. “Our goal is to work with horse owners to identify which horses are at risk and find the best diagnostic test for this condition.”

The research team need to build up a database of information on cases of the SPM, so that they can start to work out / identify the common risk factors. They hope to be able then to make suggestions of management changes to reduce the risk of the disease condition

If you suspect your horses has (or had) SPM, Dr Valberg's research team would like to hear from you. The first step is to complete a short questionnaire to see if your horse has the condition.

For more details about Seasonal Pasture Myopathy, and details of how you can help research into the condition, go to the University of Minnesota Equine Center website:

http://www.cvm.umn.edu/umec/SPM/home.html

Ancient artists spot on

Ancient cave paintings probably give an accurate portrayal of the horses that roamed the earth at the time, according to new research.

For years, archaeologists have debated whether cave paintings were intended as a realistic portrayal of life as seen by the artist, or whether they were a flight of fancy, having symbolic significance. The latter view was fuelled by the fact that, although genes for bay and black hair colour had been identified in ancient DNA, the gene for spotted coat colouring had not been found.

Now a multicentre research project has found the gene responsible for leopard spotted coat colouration in DNA from prehistoric horses.

The international team of researchers has found that all the colour variations seen in Palaeolithic cave paintings – including distinctive ‘leopard’ spotting - existed in pre-domestic horse populations, lending weight to the argument that the artists were reflecting their natural environment.

Professor Michi Hofreiter, from the Department of Biology at the University of York, said “...our results suggest that, at least for wild horses, Palaeolithic cave paintings, including the remarkable depictions of spotted horses, were closely rooted in the real-life appearance of animals. 

“While previous DNA studies have produced evidence for bay and black horses, our study has demonstrated that the leopard complex spotting phenotype was also already present in ancient horses and was accurately depicted by their human contemporaries nearly 25,000 years ago. 

“Our findings lend support to hypotheses that argue that cave paintings constitute reflections of the natural environment of humans at the time and may contain less of a symbolic or transcendental connotation than often assumed.”

Read more at equinescienceupdate.com

Management affects large intestinal motility

A possible explanation for the increased risk of impaction colic in stabled horses has been revealed by a study that shows that they have lower large intestinal motility compared with horses at pasture.

The research team, led by Dr Sarah Freeman at the University of Nottingham School of Veterinary Medicine and Science, measured the motility of the large intestine at three regions of the large intestine, using transcutaneous ultrasound.

The study involved sixteen clinically normal horses, which were divided into two groups.

Group A: Horses were stabled continuously throughout the study.
Group B: Horses were initially at pasture 24hr/day. Over a 2 week period they were gradually changed to the same stabling/dietary management as group A.

The researchers assessed the motility of large intestine twice daily for two consecutive days. They recorded the number of contractions at each of three sites: the caecum, sternal flexure, and left ventral colon.

Overall large intestinal motility as assessed by transcutaneous ultrasound was lower in stabled horses. In particular, stabled horses showed significantly fewer contractions in the sternal flexure and left ventral colon.

 Read more at www.equinescienceupdate.com

Laminitis due to endocrine disorders

Hormonal disturbance (endocrinopathy) appears to be a common underlying cause of laminitis according to research from Finland.

The study, conducted at Helsinki University Equine Teaching Hospital, looked for signs of endocrinopathy in all cases of laminitis presented for examination. Almost 90% of horses with laminitis had endocrine abnormalities.

Hyperinsulinaemia, associated with obesity was the most common cause, accounting for two thirds of all cases of endocrinopathic laminitis.  Cushing’s disease (or Pituitary Pars Intermedia Dysfunction: PPID) was responsible for a third of the endocrine-associated laminitis cases.

Dr Ninja Karikoski and colleagues examined 36 horses and ponies with laminitis. Thirty-two of them (89%) had signs of endocrinopathy.

Eleven horses had signs of PPID - hirsutism (long curly coat) and increased basal ACTH concentration or typical response to a dexamethasone suppression test.

Twenty-one horses had raised basal levels of insulin in the blood without signs of hirsutism.  All but one of these hyperinsulinaemic horses were overweight. Twelve had a body condition score (BCS) of four, (on a scale from zero to five, where five is obese) and eight had BCS of five.

The researchers conclude that, in this study, most cases of laminitis were associated with an underlying hormonal disturbance.

They suggest that endocrine testing should be performed on all cases of laminitis unless there is a clear inflammatory or gastrointestinal cause.

 Read more at www.equinescienceupdate.com

Jet lag benefits racehorses

A new study has shown that not only do racehorses cope better with jet lag than humans do, but also their performance even appears to be enhanced by it.
  
They research showed that horses adapted very quickly to a shift in time zone. Importantly, this rapid adaptation was not accompanied by an increase in the level of stress, but by alterations in endocrine systems that favour an enhancement of the horse’s physical capacity during the process.
 
In fact, following experimental jetlag, horses experienced improved athletic performance, being able to run at full gallop for an additional 25 seconds before reaching fatigue.
 
This improved performance did not persist, however, and had returned to pre-shift values after 14 days in the new lighting conditions.

 Read more at www.equinescienceupdate.com

Comparing positive and negative reinforcement training methods.

A recent study in Denmark suggested positive reinforcement methods were preferable to negative reinforcement when training horses in potentially stressful situations.

They found that found that horses trained with positive reinforcement methods trained more quickly and showed less evidence of stress. 

What is the difference between positive and negative reinforcement? In Positive Reinforcement (PR), the desired behaviour is encouraged by giving a reward as a consequence of the behaviour.

A particular behaviour can also be encouraged by removing an unpleasant stimulus. This is known as Negative Reinforcement (NR). In this case, the reward is the stopping of a negative stimulus once the correct behavioural response is achieved.

Negative reinforcement differs from punishment, in which an adverse stimulus is given as a consequence of the behaviour. This results in the behaviour becoming weaker or stopping altogether.

Twelve horses took part in the study. All had previous bad experiences with trailer loading and their owners were now unable to load them.

Horses were randomly separated into two groups. The PR group received clicker training and were trained to follow a target (a yellow ball on a stick) into the trailer. For the NR method, an adverse stimulus was applied by pulling on the lead rope, or tapping the hindquarters with a whip. This adverse stimulus was stopped as soon as the horse obeyed.

Throughout the training sessions, the research team recorded heart rate, and noted signs of behaviour and discomfort.

Comparing the two methods, the researchers found that PR provided the fastest response to training. On average, the PR group spent less time on training sessions than did the NR group.

Read more at www.equinescienceupdate.com

Progress towards a vaccine against deadly foal pneumonia

 Rhodococcus equi bacteria can cause “rattles”, a potentially lethal disease in foals which is characterized by chronic broncho-pneumonia with abscesses in the lungs. Other forms of the disease occur including infection of the intestine and lymph nodes.

Affected animals show signs of fever, cough, rapid breathing, and nasal discharge. The disease tends to develop insidiously. Few signs may be apparent until the disease is quite advanced. The organism is often found in soil, particularly in dry dusty conditions.

Treatment usually requires an extended course of antibiotics and/or immune plasma. If the infection is diagnosed too late, antibiotics are often no longer sufficient to cure the disease, and death may occur within weeks.

Despite the severity of this disease, no vaccine against it is yet available. However, researchers in The Netherlands have now developed a promising candidate vaccine.

Read more at equinescienceupdate.com

Ancient wild horses help reveal past

An international team of researchers has used ancient DNA to produce compelling evidence that the lack of genetic diversity in modern stallions is the result of the domestication process.

Modern domestic horses show abundant genetic diversity within mitochondrial DNA, which  is inherited only from the female. In contrast there is practically no variation in the DNA sequence on the male-inherited Y-chromosome.

Several hypotheses have been proposed to explain this difference, but to be able to test them it is necessary to know about the degree of variation in the ancestral horse population. The only way to get this information is by studying ancient DNA.

The research team, which was led by Professor Michi Hofreiter from the University of York, UK, has carried out the first study on Y chromosomal DNA sequences from extinct ancient wild horses and found an abundance of diversity.

The results, which are published in Nature Communications, suggest the almost complete absence of genetic diversity in modern male horses is not based on properties intrinsic to wild horses, but on the domestication process itself.

Professor Hofreiter said: “Unlike modern female domestic horses where there is plenty of diversity, genetic diversity in male horses is practically zero.

“One hypothesis to explain this suggests modern horses have little Y chromosome diversity because the wild horses from which they were domesticated were also not diverse, due in part to the harem mating system in horses, implying skewed reproductive success of males. Our results reject this hypothesis as the Y chromosome diversity in ancient wild horses is high. Instead our results suggest that the lack of genetic diversity in modern horses is a direct consequence of the domestication process itself.”

Read more : http://www.equinescienceupdate.com/articles/awhhrp.html

Identifying the cause of Foal Immunodeficiency Syndrome

Researchers in the UK have now published details of their work which resulted in the development of a genetic test for Foal Immunodeficiency Syndrome (FIS, otherwise known as Fell Pony Syndrome).

By comparing the genetic material from affected foals, known carriers with no clinical signs, and normal animals, the research team were able to track down the mutation responsible to a particular portion of chromosome 26. Further studies showed that the genetic defect affected the sodium/myo-inositol cotransporter gene (SLC5A3).

In the report of their work published in PLoS Genetics, they explain: "This gene plays a crucial role in the regulatory response to osmotic stress that is essential in many tissues including lymphoid tissues and during early embryonic development. We propose that the amino acid substitution we identify here alters the function of SLC5A3, leading to erythropoiesis failure and compromise of the immune system. FIS is of significant biological interest as it is unique and is caused by a gene not previously associated with a mammalian disease. "

"Having identified the associated gene, we are now able to eradicate FIS from equine populations by informed selective breeding."

Read more at www.equinescienceupdate.com

Effect of blinkers

How do horses respond to partial loss of vision?

In a study at Texas A & M University, eight driving horses were assessed to see if they responded differently to stimuli when wearing blinkers or not. A racing hood with half cup blinkers was used to restrict the field of view behind the horse. A similar racing hood without blinkers was used as a control.

One experimenter administered one of four stimuli while standing about nine strides behind the horse:

• a length of steel chain was dropped onto an aluminium sheet
• a children's toy gun was fired
• an aluminium can containing coins was shaken
• an umbrella was rapidly opened

The horse's heart rate was recorded after each stimulus.

They found that wearing blinkers was significantly associated with an increase in heart rate when worn by horses experiencing a noise for the first time. On the other hand, blinkers were significantly associated with a decrease in heart rate when worn by horses exposed to a primarily visual stimulus (the umbrella opening).

"It would seem logical that wearing blinkers would be advantageous when a visual distraction is hidden by the blinkers. Because the horses cannot see the object, he has no reaction to this object which is potentially frightening" they comment.

However, sounds are different. "This paper shows that horses wearing blinkers react more when they are exposed to unexpected noises." They point out that this reaction is not necessarily seen by an observer - most of the horses in the study showed little visible reaction to the noise stimuli. There was, however, a dramatic increase in heart rate.

The researchers suggest that this model of restricted vision could be used to investigate how horses react to other visual deficits such as total blindness, or the changes that occur after cataract surgery.

More details at www.equinescienceupdate.com

Catching things from horses

Two unusual cases of horse to human transmission of bacterial infections remind us of the importance of good hygiene practices when handling horses.

One report from the Netherlands concerns the suspected transmission of Methicillin-resistant Staphylococcus aureus (MRSA) type ST 398, from a foal to a 16 year old girl. The girl, who was confined to a wheelchair, developed an infected wound from which a strain of MRSA, identified as belonging to type ST398, was isolated.

Investigations into the source of the infection showed that the girl had had intensive contact with a Friesian foal. She had not been admitted to hospital in other countries, nor had she been in contact either pigs or calves - the common source of human infection with this type of MRSA.

Swabs from other members of the girl's immediate family and other animals in the household were negative for MRSA

The type of MRSA involved,  ST398, is one which is associated with livestock and has been spreading in Europe and North America. It is the most common type of MRSA identified in horses in the Netherlands.
 
The authors suggest that the foal was the most likely source of the infection. In fact, the foal itself had been hospitalised in an equine clinic two months earlier for treatment of a wound infection.

Another report describes a surgical operation that became infected with Streptococcus equi.

S. equi, the cause of strangles in horses, is a cause of great concern to many horses' owners, but is rarely a danger to humans or other domestic species.

The patient, a professional racehorse trainer, underwent treatment for an aortic aneurysm - a condition in which the walls of the main artery leaving the heart are weakened and balloon outwards. If untreated there is a risk of sudden rupture leading to sudden death.

A specialised endovascular technique was used, in which a stent, a tubular framework,  was inserted into the femoral artery in the groin, and passed up the artery until it came to lie within the affected vessel.

The stent became infected and the causative organism was identified as Streptococcus equi.

Read more at www.equinescienceupdate.com

Faecal egg counts after tapeworm treatment

It may be more useful to look for tapeworm eggs the day after treatment rather than before. Research carried out by Johanne Elsener of Wyeth Animal Health and Alain Villeneuve of the Faculté de Médecine Vétérinaire, Université de Montréal looked at whether treating for tapeworms one day before carrying out a faecal examination improved the chance of identifying infected animals

The study involved horses of differing ages on a single stud farm - from weanlings to adult breeding mares and stallions.

All horses were presumed to be naturally infected with Anoplocephala perfoliata - as tapeworm-infected animals had been identified previously on the farm.

The horses were weighed and dosed according to weight.

The researchers examined faecal samples before and 24-48 hours after treatment with a paste containing praziquantel (and moxidectin). Faecal samples were examined using a modified Wisconsin sugar centrifugation technique - performed by a technician who was unaware of the treatment given to each .horse.

Overall, the researchers found that they were twice as likely to detect tapeworm eggs in the faeces of horses 24 - 48 hours after treatment with praziquantel than they were before treatment.

In adult horses (mares and stallions) the difference was statistically significant. Young horses (weanlings, yearlings and two year olds) showed a numerical increase in positive horses after treatment, but the difference was not statistically significant.

The two-year old horse group had the highest proportion of positive faeces, (66% horses were positive before treatment)

The researchers conclude that sampling after treatment may give a better idea of the true prevalence of tapeworm infection.

More details at equinescienceupdate.com

Does soaking make hay safer for laminitics?

An important part of treatment and prevention of laminitis is to limit the water soluble carbohydrate (WSC) intake. To achieve this, access to pasture is restricted and the horse or pony is fed hay instead.

But even hay may not be safe for horses with laminitis. Most authorities suggest that horses and ponies prone to laminitis or with insulin resistance should ideally receive hay that has a water soluble carbohydrate concentration not exceeding 100g/kg on a dry matter basis (DM)

However, in northern Europe pasture grasses often contain high levels of WSC (>300g WSC/kg DM), which may result in hay with WSC content up to 200g/kgDM.

It is often suggested that soaking the hay may reduce its water soluble carbohydrate content and thus make it safer for laminitis-prone horses and ponies. However, the studies that have supported this approach have often used large quantities of water and, as well, the hay may have been chopped prior to soaking.

Often owners do not go to such lengths. What is the effect of soaking hay when carried out according to common practice?

Dr Annette Longland, Clare Barfoot and Dr Pat Harris conducted an investigation into whether the degree of soaking that is in common use in the UK would have an effect on the WSC content of various hays.

The study looked at the loss of WSC and crude protein from a range of British hays, which were either shaken or left compacted in the "flake" and then soaked in just enough water to cover the hay, for various lengths of time.

The authors found that soaking hay for up to 16 hours produced variable and incomplete loss of WSC.
As would be expected, the dry matter content of the hays fell after soaking - there was a significant reduction in DM content after 20 minutes soaking, and a continued fall with longer periods of soaking.

However, regardless of the duration of soaking or whether the hay was shaken up or left compacted the WSC content of most of the hays remained above the recommended limit for laminitics of 100g/kgDM.

The researchers found no significant difference between the compacted or shaken hays. They conclude that soaking cannot be relied on to make hay suitable for feeding to laminitic horses.

They recommend that hay for animals prone to laminitis be analysed for WSC content, and only hay that is low in WSC is fed to horses prone to laminitis. Soaking can be used as an extra safeguard.

How does a brumby stallion spend his day?

Magdalena Zabek's latest report on the feral horses of central Australia is now available. Click here to read

Research confirms effectiveness of grazing muzzles

Using a grazing muzzle appears to be more effective than restricting access to pasture, for reducing the amount of grass eaten by ponies, according to a recent study.

Pasture intake by the ponies grazing for three hours without muzzles averaged 0.8% (with some eating close to 1%) of their bodyweight, which is the equivalent of up to two thirds of the recommended daily dry matter intake  for many ponies on restricted diets.

In contrast, the pasture intake of the ponies when wearing muzzles was around 0.14% of bodyweight over three hours, representing an average reduction of 83% compared to when they were not wearing muzzles.

Read more at www.equinescienceupdate.com

Making sense of flexion tests

Flexion tests are often used as part of a prepurchase examination or a lameness work-up to evaluate lameness or assess the likelihood of future lameness problems. But what does a positive flexion test tell us about which structures are involved?

Research published in the Equine Veterinary Journal suggests that the fetlock is probably responsible for a positive response to flexion test of the lower limb. Structures below that joint are less likely to be involved.

Dr Clodagh Kearney and colleagues conducted a study on eight warmblood horses. These were all clinically sound, but had gone lame after being subjected to a flexion test of the lower limb. Flexion tests were performed under standardised conditions.

The response to the flexion test was assessed after performing various nerve blocks, which desensitised different regions of the limb. One clinician performed the nerve blocks; others performed the flexion tests and assessed the degree of lameness. So the clinicians assessing the lameness did not know which nerve block had been carried out (or on which leg).

They found that a nerve block of the palmar digital nerves, just above the cartilage of the distal phalanx, had minimal effect on the lameness induced by the flexion test. A nerve block just below the fetlock at the level of the distal abaxial sesamoid bones produced a similar response. However, there was a marked improvement in flexion test induced lameness following a low four point block just above the fetlock.

The researchers conclude that the fetlock joint and surrounding structures contribute strongly to the outcome of a flexion test of the lower limb in a non lame horse. "From a clinical point of view, it is reasonable to suggest that the flexion test of the distal limb may be sensitive for investigating the metacarpophalangeal joint region, but may be less relevant for structures distal to this joint."

Read more at www.equinescienceupdate.com

Treponemes found in canker lesions

Japanese research has found evidence of treponemes in equine canker by looking for specific portions of RNA characteristic for the organisms.

Canker is a chronic proliferative condition of the horse's foot - affecting the frog and bars and sole. In severe cases it may extend to involve the hoof wall. Similar conditions in cattle and sheep have been shown to be associated with spirochete bacteria - in particular treponemes.

Dr Kyaw Kyaw Moe and colleagues examined samples from lesions in two horses and compared them with samples from an unaffected horse.

They found spirochetes in microscopic sections of the canker lesions. They also found 114 clones in the affected horse samples and none in samples from normal horses.

The clones could be classified into 19 separate groups - corresponding to many different treponemes, including those implicated in bovine papillomatous digital dermatitis.

Despite this the researchers were unable to culture the organisms. This is not surprising as treponemes are slow growing and are often overgrown by more rapidly growing bacteria.

The research confirmed the presence of treponemes in canker lesions in two horses and their absence in a normal horse. However, as the study was based on only a couple of cases, the researchers could not confirm that treponemes are the cause of canker - further work is required involving more cases.

Read more at equinescienceupdate.com

Effect of psyllium on glucose and insulin

Psyllium, a sort of "super-bran", is already used in horses, particularly for treatment and prevention of sand colic. When mixed with water, it swells to up to 10 times its original volume, turning into a jelly-like substance which is thought to ease the passage of sand through the digestive tract.

Researchers at Montana State University conducted a trial to see if adding psyllium to a horse's diet had an effect on glucose and insulin metabolism. It had been noticed previously that psyllium had a beneficial effect on insulin sensitivity, when taken by people with insulin resistance. So they wanted to investigate whether a similar effect occurred in horses.

They used 16 healthy horses (8 mares and 8 geldings), which they divided into 4 groups of 4, each containing 2 mares and 2 geldings. All horses were fed a diet of mixed grass hay and a commercial whole grain feed twice a day. Psyllium pellets were added to the grain ration of three groups at 90g, 180g, or 270g daily. The fourth group received the same diet, but without added psyllium.

On the 60th day the researchers withheld food from the horses overnight. In the morning they collected blood samples before the morning feed and then every 30 minutes for six hours, to monitor the blood glucose and insulin concentrations.

The researchers found that on average, horses that had been receiving psyllium for 60 days had lower average peak glucose levels after feeding and lower average glucose levels. Psyllium-fed horses also had lower peak insulin levels and lower average insulin levels after feeding compared with horses that had not received psyllium.

Dr Shannon John J Moreaux, Assistant professor of Equine Science at Montana State University, and one of the research team commented. "Psyllium could be especially beneficial to obese, insulin-resistant horses, or horses that are predisposed to developing laminitis because of metabolic syndrome". He added that it was commercially marketed and readily available to horse owners, and when fed daily, may help to maintain lower post-feeding blood glucose and insulin levels.

This was a small study carried out using normal horses. Before we can conclude that psyllium will benefit insulin resistant horses, further research is needed using affected horses.

However, if it proves to be effective in insulin resistant horses it could provide a useful addition to the strategies available for managing this condition.

Read more at equinescienceupdate.com

Is your vet a health risk?

Vets that work with horses are more likely than other vets to carry methicillin-resistant Staphylococcus aureus (MRSA), according to an Australian study.

The researchers, led by Dr David Jordan, collected nasal swabs from 771 individuals, who were also asked for details of the type of work they did and with which species.

Analysis of the data showed that veterinarians that worked mainly or exclusively with horses were more likely the carry MRSA in their nostrils.

MRSA was present in 5.8% of those taking part in the study. However, the data revealed differences depending on the type of work the individuals performed.

Positive swabs were obtained from 11.9% of veterinarians who spent a lot of their time on horse work. (This was 13 times that of the vets involved in industry or government work. Less than 1% of them had positive swabs).

The figures were even higher among people who worked only with horses.  The results showed that 21.35% of them had nasal swabs positive for MRSA. (They were 23 times more likely to have their nostrils colonised by MRSA than were vets working for government or industry.)

Considering the extent of carriage of MRSA and the seriousness of the disease it can cause in humans and animals, Dr Jordan recommended that vets should take more precautions to prevent the spread of MRSA

"The higher than normal prevalence of MRSA carriage among veterinary clinicians in Australia is a cause for concern in the profession and warrants further investigation for specific risk factors, particularly for vets who work with horses"

He suggests that guidelines specific for equine work are needed. These should include: "enhanced personal hygiene during handling of animals; better sanitary management of premises, equipment and waste; greater awareness of biosecurity during handling and surgical procedures; and reform of use of antibiotics - especially those of importance in human medicine such as the fluoroquinolones, third generation cephalosporins and gentamicin."

Read more at www.equinescienceupdate.com

Hendra virus vaccine progress

Australian scientists have succeeded in developing an experimental vaccine to protect horses against Hendra virus.

Hendra virus (HeV) was first isolated in September 1994 from an outbreak at a training complex in Hendra (a suburb of Brisbane, Queensland, Australia) after which the virus was named.

During that initial outbreak 14 horses died. Seven other horses were found to have been infected and were humanely destroyed. Two humans were affected, one of whom died.

In five of the 14 known outbreaks, the infection has spread to people. The virus has killed four of the seven people infected.

Fruit bats (Pteropus spp), commonly known as flying foxes, have been identified as the natural host for the Hendra virus.

“Our trials so far have shown that the vaccine prevents the infection of horses with Hendra virus,” said Dr Deborah Middleton from the Australian Animal Health Laboratory (AAHL).

Stopping the disease in horses could also help protect people from the disease.

"All the human infections have come from contact with infected horses," Dr Middleton explains. So if you can control the disease in horses, you break the transmission cycle to people as well as protecting the health of horses.

Studies so far have shown that the vaccine will prevent horses becoming infected. It also protects them from developing the disease and shedding the virus.

Further work, including field trials and product registration, is still required. However, if all goes well, the vaccine may be available as soon as 2012.

Dr Barry Smyth, President of the Australian Veterinary Association, said that both vets and horse owners would welcome the news on the vaccine.

“It’s important that veterinarians and horse owners continue with precautions that reduce the risk of spreading the virus and that they report suspected cases immediately,” Dr Smyth said.

Read more at: www.equinescienceupdate.com

Saddle research uncovers new theory in asymmetry

The Saddle Research Trust (SRT), believe they have discovered a new theory in rider asymmetry, which they feel will have implications for equine performance and welfare.

Following a series of pilot studies carried out in conjunction with educational establishments throughout 2010, the charity claims to have evidence that highlights previously unidentified areas and measurable characteristics of saddle performance.

Anne Bondi BHSI, Director for the trust explains: “The initial objective of our early pilot studies was to measure the effect of the rider asymmetry using a variety of scientific measuring systems open to the trust. It soon became apparent that a more complex pattern of interaction was occurring, one that could not just be explained by a rider sitting crookedly.”

Humans are not perfectly symmetrical, and most riders are aware of being right or left handed. This ‘handing’ often creates a loss of symmetry in the rider in the vertical plane.

“After observing this common occurrence we began to examine further the effect the saddle has on the rider and their posture” she continues.

A similar lack of symmetry also exists in the horse in the horizontal plane. The movement of a horse’s back and limbs creates movement in the saddle, generating an unstable platform for the rider. This forces riders to adopt a compensatory action - accentuating the already asymmetrical posture. The horse also compensates for carrying the asymmetrical rider by counterbalancing.

According to the SRT, this is far more complex than a ‘chicken and egg’ situation. It involves a mixture of symptoms involving asymmetries in the horse, rider and saddle, but more significantly the interaction between them.

"Our studies to date have shown a clear lack of synchronisation in this three-way interaction, and it is our understanding that the degree to which this occurs is greatly affected by saddle design and fit."

“We have raised many new questions about the effect of saddles on asynchrony, as well as identifying measurable characteristics in saddle performance. Although our work is in its infancy we believe it will have far-reaching effects on all levels of equestrianism.”

Read more at www.equinescienceupdate.com

Bedding dope test risk

Flunixin excreted in the urine may be ingested with bedding, risking prolonging the time taken to clear the drug from the body.

Owners and trainers should be aware that horses may recycle anti-inflammatory drugs such as flunixin in the stable environment. This may prolong the time the drug is detected in the urine - thus increasing the risk of positive dope test.

Flunixin is a non-steroidal anti-inflammatory drug commonly used in horses. The rules of many disciplines prohibit its presence in the blood or urine of horses on the day of competition.

Detection times have been established for some medications to help veterinarians advise owners and trainers on how long before a competition treatment should be withdrawn to minimise the risk of the drug being found in the urine. However, research in France shows that the problem can be complicated by horses absorbing flunixin from bedding that has been contaminated by urine containing the excreted drug.

Work at the Laboratoire des Course Hippiques, found that, even if bedding is removed completely and the floor brushed out, there is still a risk of a "rebound" increase in urine flunixin levels.

Dr Marie Agnès Popot and colleagues looked at the excretion profiles of flunixin in urine collected from horses under various systems of stable management. They gave flunixin as either a single intravenous dose (1mg/kg) or as an oral paste (0.5mg/kg twice daily for 3 days).

Horses were housed in stables from which the bedding was either completely removed on a daily basis, or only "skipped out" (removing only soiled bedding on a daily basis, and cleaned completely once a week.)

The largest rebound in urine flunixin concentration was seen in those horses kept in stables that were not cleaned completely on a daily basis. However, removing all the bedding and sweeping the floor could not totally prevent rebound in flunixin levels. The only circumstance in which a rebound in urine flunixin levels did not occur was when the drug was given intravenously and the horse was moved to a clean stable after 24 hours.

"Flunixin is mainly eliminated by renal clearance and a large amount of flunixin is eliminated in urine within the first 24 hours following administration" the researchers explain in a report in the Journal of Veterinary Pharmacology and Therapeutics. "Then, for horses housed in unclean boxes, the conditions  exist for the possibility of prolonged recycling; the only way to break recycling is to move the horse in  another separate box after the first 24 hour of treatment, rendering unavailable the flunixin excreted in the urine for the first 24 hour."

They conclude that attention to stable hygiene can drastically reduce the risk of spurious drug excretion profiles for drugs such as flunixin that are mainly eliminated in the urine.

Read more at www.equinescienceupdate.com

Focusing on the next obstacle

Elite riders' eye movements may be key to show jumping success. Research from Nottingham Trent University found that an experienced show jump rider focused on the jump up to 3.05 seconds earlier before take off than did a less experienced non-competitive rider.

http://www.ntu.ac.uk/news_events/news/releases/eyegaze.html

Mares behaving badly

Plant oils might provide the answer to mares that are unruly when in season.

Some mares become unruly and difficult to manage when in season and perform poorly as a result. Various methods of controlling this behaviour have been suggested. Most are based on suppressing the oestrus cycle.

Sandra Wilsher and Professor Twink Allen at the Paul Mellon Laboratory of Equine Reproduction, Newmarket, England, were investigating the mechanisms of maternal recognition of pregnancy.

They found that intrauterine administration of oestrogen in fractionated coconut oil prevented mares returning to oestrus, However, they also found that the coconut oil alone (without oestrogen) had a similar effect, as did peanut oil.

Fractionated coconut oil was most effective when given 10 days after ovulation - luteolysis was delayed in 11/12 mares (92%). It was not as effective on days 8-12., although the difference was not statistically significant. When administered on the 6th day after ovulation, it inhibited luteolysis in only 25% of mares. 

Oestrogen in mineral oil, or mineral oil on its own did not block luteolysis when given 10 days after ovulation.

So it seems unlikely that embryonic oestrogens are important in the maternal recognition of pregnancy.

Fractionated coconut oil and peanut oil each contain various different fatty acids.  The researchers were unable to identify an individual component that was responsible for inhibiting luteolysis.  Instead, they suggested that it is likely that a range of fatty acids are capable of causing luteal persistence.

Further work is required to determine how the vegetable oils have this effect. However, it does seem that they may provide a practical way of preventing unruly behaviour in oestrus mares.

Read more at www.equinescienceupdate.com/articles/popmb.html

Sublingual detomidine for needle-shy horses

How do you sedate a needle shy horse? Recent research suggests that detomidine, a sedative commonly used in horses, can be effective when administered under the tongue.
 
Detomidine is a popular choice for sedating horses, capable of producing profound sedation when administered intravenously.

Previous studies have shown that detomidine is not effective when administered by stomach tube, and is variably effective when mixed with food. However it seems to be absorbed through the gums and appears to be effective when given sublingually.

Recent research looked at the value of sublingual detomidine for sedating horses known to need sedation to permit routine management or veterinary tasks - such as farriery, routine dentistry, passage of a stomach tube or clipping.

The study by Dr Rachel B Gardner and colleagues was published in the Journal of the American Veterinary Medical Association.

Horses used in the study were all known to require sedation or strong additional restraint - such as a twitch - to allow the procedures to be carried out.

The treatment group comprised 129 horses treated with detomidine sublingually, at a dose of 0.04mg/kg (double the usual dose when given intravenously).

A further 42 horses were treated with a gel which appeared identical, but did not contain detomidine. The study personnel did not know whether they were administering the detomidine gel or the placebo.

The efficacy of the treatment was assessed according to whether it allowed the required procedure to be carried out. Treatment was only considered successful if the procedure could be completed without resort to further sedation or the use of a twitch.

The procedures were completed successfully in 98 of 129 (76%) of detomidine treated horses compared with only 3 of the 42 (7%) of control horses. Little or no ataxia was reported in 70% of detomidine treated horses

Sublingual detomidine was most successful for sedating horses for manual teeth floating and hoof trimming and shoeing. It gave a lower success rate for clipping with electric clippers - only half of the detomidine-treated horses could be clipped successfully.

For more details see:

Efficacy of sublingual administration of detomidine gel for sedation of horses undergoing veterinary and husbandry procedures under field conditions.
RB Gardner, GW White, DS Ramsey, JE Boucher, WR Kilgore, MK Huhtinen
J Am Vet Med Assoc (2010) 237, 1459 - 1464

No benefit in metformin IR study

A study into the pharmacological management of insulin resistance using metformin, failed to demonstrate any benefit.

The research was conducted by the School of Animal and Veterinary Sciences, Charles Sturt University in New South Wales, Australia and the Department of Clinical Studies, New Bolton Centre, University of Pennsylvania, PA, USA, in collaboration with the Waltham Equine Studies Group. Lead researcher was PhD candidate Kellie Tinworth.

In insulin resistance, insulin seems unable to exert its normal effect. This is particularly noticeable in relation to glucose metabolism. As a result, the body releases increasing amounts of insulin, ending up with normal or raised blood glucose levels despite high concentrations of insulin.

Insulin resistance appears to be a significant risk factor for conditions such as laminitis.

Therefore, it is important to prevent IR from developing, or to manage it before it contributes in turn to the development or progression of other potentially life-threatening conditions.

While the correct management of energy intake and exercise levels is thought to be essential, in some cases medication is also considered, especially when increased exercise is not possible.

No licensed drugs are currently available for treating insulin resistance in horses and ponies. Metformin has been suggested as a possible treatment for the condition. It appears to enhance insulin sensitivity of peripheral tissues without stimulating insulin secretion.

The research team hoped to confirm that metformin had a positive effect on insulin and glucose dynamics in insulin-resistant ponies, so that it could be used as a positive control in other studies.

Six ponies that were insulin-resistant, but not obese, took part in the study. Three ponies were allocated to the treatment group, and they received metformin (at 15mg/kg bodyweight orally, twice daily) for 21days. The control group received a placebo.

After a "wash out" period, the trial was repeated with the ponies being swapped between the treatment and placebo groups.

The response to metformin (and the placebo) was assessed using a frequently-sampled intravenous glucose tolerance test (FSIGT).
 
The researchers found no measurable benefits of metformin. No significant change was noted in any of the indices of insulin sensitivity. Neither was there any change in bodyweight, body condition score or cresty neck score.

Read more at: www.equinescienceupdate.com/articles/nbmir.html

Role of bacteria in periodontal disease

Bacteria may be more important in the development of periodontal disease in horses than previously thought, according to research carried out at the University of Edinburgh.

Equine periodontal disease is a common condition in horses affecting around 60 percent of horses over the age of 15 years. The disease is painful and can have a big impact on a horse's quality of life, affecting the animal's ability to eat and its performance.

Bacteria are known to be a cause of periodontal disease in humans, cats and dogs, but it is less clear what role they play in the disease in horses. Mechanical factors, such as food being packed between the horse's teeth due to abnormal growth and spaces have been considered to be the primary cause.

Research, carried out by Alistair Cox, is believed to be the first to describe the microscopic anatomy of equine periodontal disease.

Cox examined the skulls of 22 horses that had been submitted for post mortem examination. Although none of the horses had received treatment for periodontal disease, 16 had some form of periodontal disease.

"This research, funded by The Horse Trust, highlights how common periodontal disease is in horses. Yet many horses don't receive treatment so are likely to be suffering in silence. I would advise all horse owners to get their vet or equine dentist to regularly check their horse to see if it is developing the condition," he said.

Cox identified bacteria, including spirochaetes, that were associated with periodontal disease. Spirochaetes are known to be important in human and canine periodontal disease, but this is the first study to identify them in association with the condition in horses.

"This study shows that bacteria may be more important than was previously thought in the development of equine periodontal disease,” said Cox

"More research is needed to understand whether bacteria or mechanical factors are the main cause of the disease. Once we have a better understanding of why and how the disease develops, we can do more to prevent horses from developing this painful condition."

Read more at: http://www.equinescienceupdate.com/articles/rbpd.html

FIS test success

One year on, the test for Fell Pony Syndrome, has been acclaimed a great success.

As the genetic test identifies carrier animals, it can be used to prevent affected foals being conceived.  The disease only appears when both parents carry the mutation. Breeders can avoid producing affected foals by ensuring that they do not breed two carriers together.

Of the almost 1000 animals tested, 47% of Fell ponies and 10% of Dales ponies were found to carry the mutation for the disease.

The fatal disease is now known as Foal Immunodeficiency syndrome (FIS), as cases are not confined to one breed. Affected foals die or are euthanased, usually before they reach three months of age.  

Since February 2010, when the test became available, nearly 1000 samples have been tested. Three quarters of the samples came from Fell ponies. Of those tested, 47% of Fell ponies and 10% of Dales ponies were found to carry the mutation for FIS.

The test was developed as the result of research led by Dr June Swinburne of the Animal Health Trust, Newmarket. 

"This test, developed using funding from The Horse Trust, has been a massive success among the Fell and Dales pony breeding communities," she said. "We hope the test will prevent unnecessary suffering among Fell and Dales pony foals as breeders can now easily prevent the conception of foals with FIS. As so many breeders tested their breeding stock last year, we hope there will be very few foals affected by this horrendous disease in the future."

Read more at: http://www.equinescienceupdate.com/articles/fists.html

Does restricting grazing really reduce grass intake?

A recent study suggests that limiting access to pasture may not be effective at reducing grass intake by ponies

 

Recent research, about to be presented at a biannual nutrition meeting in the US, suggests that ponies given reduced access to pasture can eat considerable amounts of herbage during the time they are turned out. Indeed they may even increase their intake during this time as they become accustomed to the routine.

Intake of large amounts of fructan, and other rapidly fermentable carbohydrates by grazing ponies has been linked to the development of laminitis.  It has become common practice to restrict ponies’ access to pasture, especially at key times of the day/year in order to reduce the risk.

The study, which was conducted at the Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, in collaboration with the WALTHAM Equine Studies Group, aimed to investigate the effect of grazing restriction on herbage intake and grazing behaviour in ponies.

The grazing behaviour of eight ponies was measured daily over a six week period to assess their voluntary intake of herbage and to monitor the effects of restricting their access to pasture. Two groups of four pony mares were used. Group A had 24 hour access to pasture. The ponies in group B had three hours of pasture access daily and were stabled for the remaining 21 hours, with free access to haylage and water.

Herbage intake was estimated during the three hours when all the ponies were at pasture by monitoring the change in weight of each individual over the period. Grazing behaviour was analysed from video footage of the two groups using interval sampling. The ponies in the restricted grazing group had higher estimated grazed herbage intakes than those with 24 hour access to pasture .during the three hours studied. The difference was significant during the final week, when the restricted grazing group consumed 40% of their total daily dry matter intake as grass in the three hours at pasture. This compared with an intake of grass of around 25% of their daily dry matter ingested during the first week.

 

Clare Barfoot, research and development manager at SPILLERS®, said: “This suggests that ponies with reduced access to pasture are capable of ingesting considerable amounts of grass during the time they are turned out and may indeed progressively increase their intake during this time, indicating that the behaviour could be learned. The implication is that reducing ponies’ time out on normally managed pastures with the view to limiting the intake of rapidly fermentable carbohydrates may not be as effective as first thought.”

Reference:

Changes in proportions of dry matter intakes by ponies with access to pasture and haylage for 3 and 20 hours per day respectively for six weeks. 

 J. Ince,A. Longland,C. J. Newbold,P. Harris.  

Journal of Equine Veterinary Science (2011) (in press)

Vancomycin-resistant bacteria in equine manure

Horses are not likely to play a major role in the spread of one type of antibiotic resistant micro-organism, to humans, according to a study in North West England.

Work reported at the International Conference on Antimicrobial Research in Valladolid in Spain November 2010 looked for vancomycin resistant enterococci (VRE) in equine faeces.

Lead researcher Dr Mohamed O Ahmed presented the results of the study, which looked at faecal samples from 66 hospitalised and 72 non-hospitalised horses.

Enterococci are enteric bacteria found in the digestive tract of many humans and animals. They may be responsible for urinary tract or wound infections (i.e. nosocomial infections). Also in patients with suppressed immune systems, they can cause serious conditions such as infection of the heart valves (endocarditis) and brain (meningitis).

Enterococci are naturally resistant to many antibiotics. One of the few last-choice antibiotics used for treating people with serious enterococcal infections is vancomycin.

Vancomycin-resistant enterococci is an emerging nosocomial organism, reportedly of zoonotic nature. There are several strains of vancomycin-resistant enterococci. The genes conferring resistance have probably been acquired from other types of bacteria that don't cause disease, but are already vancomycin resistant.

If specific vancomycin-resistant strains were present in horse faeces (i.e. VanA and VanB phenotypes) they could act as a zoonotic source of infection.

Overall, the researchers identified 47 suspected VRE isolates from a total of 264 faecal samples. Of those, only 9 were confirmed by polymerase chain reaction (PCR). Seven were confirmed as VanC genotype. Six of these were found in samples from hospitalised horses.

They identified one isolate each of VanA and VanD genotype. Both of these were in non-hospitalised horses, but neither could be typed by PCR.

The VanA genotype has been reported predominantly as the one involved in human infections. However, the VanC genotype, which was found most frequently in this study, is not commonly isolated in cases of human infection.

The researchers conclude that it is unlikely that horses play a major role in the transmission of VRE to humans in that specific geographic area. Also, the fact that most of the VRE isolates were found in hospitalised horses, suggests that hospitalisation could increase the risk of transmission between horses and possibly to humans too. Future research may be needed to look into this.

Read more at www.equinescienceupdate.com

Study finds whipping racehorses pointless

Whipping has no effect on the likelihood of a horse winning or being placed, according to a recent report. The authors conclude that whipping tired horses in the name of sport is very difficult to justify.

Dr David Evans and Professor Paul McGreevy based their findings on the horses’ speed, the number of times they were whipped and their place in the field. The information was gathered from five sprint races (over 1200-1250 meters) at the racetrack at Canterbury, New South Wales. 

“When we compared the sectional times 600-400m, 400-200m, 200m – finish, horses ran fastest in the 600-400m section, during which no horses were whipped”  Dr Evans explained. “Horses achieved their highest speeds during the last 600m of the races without being whipped.”

 “Increased whip use was most frequent in the final two 200 metre sections when horses were fatigued.''

“Analysis of the data showed that the strongest predictor of racing success was where a horse was placed at the 400m and 200m marks. Neither whip counts in the final 400m or 200m, nor velocity in the final 200m, significantly explained the probability of finishing 1st, 2nd or 3rd,” Prof McGreevy added.

“That said, it remains possible that whip use in the final stages of a race really does improve relative performance at a stage when all horses are slowing, but more frequent and sensitive methods of measuring velocity may be required to detect such a cause and effect linkage.” 

The authors conclude, “These data make whipping tired horses in the name of sport very difficult to justify.”

For more details see:

http://www.equinescienceupdate.com/articles/sfwrp.html

Equine Guelph survey research

Equine Guelph offer you the chance to influence their research and education programs so they meet the needs of the equine industry. 

Complete their survey and you can enter a draw for one of two gift certificates for an Equine Guelph online course of your choice (valued at $549.00) 

http://www.surveymonkey.com/s/industrysurvey_enews_1

Mistletoe for treating equine sarcoids?

 Could a festive winter decoration provide the cure for equine sarcoids?

Sarcoids are the most common skin tumour of horses. They are difficult to treat, and may recur after treatment.  A new therapeutic option has been suggested by a Swiss study, which found that an extract of mistletoe was an effective treatment.

The findings have been reported in the Journal of Veterinary Internal Medicine. Lead author was Ophélie Christen-Clottu of the Research Institute of Organic Agriculture, Frick, Switzerland.

The study compared the response of sarcoids to treatment with an aqueous extract* of the pine mistletoe (Viscum album ssp. austriacus) and a placebo.

Mistletoe contains compounds, like lectins and viscotoxins that have been shown experimentally to have cytotoxic and growth inhibiting properties and immune modulating activity. Extracts are used as an adjunct to treatment of cancer in human medicine.

The treatment consisted of injections of 1ml of mistletoe extract in increasing concentrations (from 0.1mg/ml to 20mg/ml) administered 3 times a week for 15 weeks. Control animals were injected with 1ml of saline at similar intervals.

The researchers monitored the location, number, and type of sarcoids present for a year after the start of the study. Neither they nor the horse owners knew which horses were treated with the mistletoe preparation or the placebo until the end of the study.

Fifty-three horses, with a total of 444 sarcoid lesions, were treated - with either mistletoe extract or placebo. Forty-two horses were treated as monotherapy and 11 horses were treated with mistletoe extract or placebo after selective surgical excision of some sarcoids.

Five of the treated horses developed mild oedema at the site of injection when the higher concentration injections were given. This swelling disappeared within a few days without treatment.   No other adverse effects were noted.

At the end of the study, sarcoids were no longer visible in 9 of 32 mistletoe extract treated horses and 3 of 21 placebo control horses. This difference was not statistically significant. However, another 4 horses in the VAE group showed reduction in more than half of the sarcoids.

So, overall, 41% of horses in the treatment group showed complete or partial regression of the sarcoids - which was significantly different from the response in the placebo group.

The curative effects were higher in verrucous sarcoids than by other types of sarcoids. On advantage of VAE treatment is the systemic effect: if treatment is successful, all tumors of one horse can regress. The disadvantage of the therapy was  that response to treatment was slow - being seen only after the end of the 15 week treatment period in many cases.

They conclude that mistletoe extract proved effective for treating clinically diagnosed equine sarcoid in this study. They suggest that it can be recommended particularly when excision may not be appropriate, for example for sarcoids around the eyes or for cases with multiple sarcoids.

See: www.equinescienceupdate.com/articles/mftes.html

Striving to prevent foal pneumonia

News that a vaccine against Rhodococcus equi is entering the final stages of development offers the hope of preventing this serious respiratory condition of foals.

R equi causes chronic broncho-pneumonia with abscesses in the lungs, typically affecting foals less than six months old. Other forms of the disease occur including infection of the intestine and lymph nodes.

Rhodococcus equi does not only infect horses. It is an opportunistic human pathogen associated with diseases that result in suppression of the immune system.

The organism is found in soil, especially in the presence of horse faeces, which provides the substrate on which it feeds. It is well equipped to resist desiccation. Foals are infected by inhaling contaminated dust.

Treatment is difficult. The organism is resistant to many common antibiotics. It lives within the macrophages, making it difficult for antibiotics to reach it.  A long course of suitable antibiotics - such as erythromycin and rifampin - is required to effect a cure.

As yet there is no effective vaccine. However, on January 27, 2011, Intervet / Schering-Plough Animal Health announced that a vaccine against Rhodococcus equi infection in foals was entering the final stages of development.

The vaccine is based on a special non-pathogenic strain of the bacterium. Four genes have been deleted from its genome, to make the bacterium incapable of causing disease, but still able to stimulate immunity.

Preliminary studies have shown that the genetically modified strain is safe, and unable to cause disease in foals as well as in calves chickens, pigs rats and mice.

Approval has now been given for field trials to commence. These will start shortly in Germany. In the first phase of the study, a group of foals will be vaccinated with the candidate vaccine and will be compared to a group of non-vaccinated foals. The number of R equi infections will be evaluated in each group.

An effective vaccine against R equi would be a great step forward in the control of this disease.

see: http://www.equinescienceupdate.com/articles/revt.html

Gene for PSSM type 1 in European draught breeds

PSSM is a metabolic disease that results in the accumulation of glycogen and abnormal polysaccharide in muscle.

A genetic mutation of the glycogen synthase1 gene (GYS1) has been identified as the cause of some cases of PSSM in quarter horses and North American draft breeds. This form of the disease has been classified as type 1 PSSM.

A recent study has now also found the GSY-1 mutation in continental European draught breeds.

With the cooperation of the breed societies, Dr John Baird and colleagues sampled Ardenner, Belgian Draft, Breton horse, Comtois, Trait du Nord, Hispano-Breton, Netherlands Draught horse, and German cold bloods.

Overall 62% of continental European draft horses possessed the GYS-1 mutation. The mutation was present in all breeds sampled and in all six countries (Belgium, France, Spain, Germany, Sweden and the Netherlands.)

Of the breeds in which more than 15 animals were tested, the Belgian trekpard had the highest number of horses with at least one copy of the GSY1 gene (92.1%). Over a third of the Belgian trekpard tested were homozygous for the GSY1 allele - that is they carried two copies of the defective gene. The mutation was also present in over 50% of the animals tested from the Comtois (79.8%), Netherlands trekpard (73.9%), Rheinisch-Deutsches kaltblut (68%) and Breton (64.4%) breeds.

"What is striking from the present study" say the authors" is that a high percentage of horses derived from continental European draught breeds, in fact, often the majority of horses tested in each breed, were positive for the GYS-1 mutation."

However they stress that, as the research was not based on random samples, it cannot be relied on to give an accurate assessment of the prevalence of the GSY-1 mutation in continental European breeds.

For more details see: http://www.equinescienceupdate.com/articles/gpedb.html

Latest stem cell research results

Stem cell treatment reduces the rate of repeat injuries when used for treating superficial flexor tendon injuries in racehorses, according to research at the Royal Veterinary College.

Professor Roger Smith developed a technique for harvesting stem cells from the bone marrow, multiplying them in the laboratory and then implanting them back into damaged tendon.

So far, the procedure has been used in over 1500 horses throughout the world. Monitoring the healing process using ultrasound scans showed that the hypoechoic "core" lesion filled in quickly, although a reduced longitudinal striated pattern usually persisted.

A study of the clinical outcome in 113 treated racehorses, found that the re-injury rate was significantly lower in stem cell treated horses than in conventionally treated horses.

Histopathological examination of 17 tendons from post mortem samples obtained from horses that  had undergone stem cell implantation showed both good quality healing with minimal inflammatory cells, and crimped organised collagen fibres.

A further experimental study found that stem cell treated tendons had more normal mechanical  characteristics and their shape, appearance and composition were also improved. Tendon cross-sectional area, cellularity, crimp pattern and DNA content were all significantly better in the treated tendons than in the saline controls. Read more at www.equinescienceupdate.com

Obesity in English horses

Obesity is likely to be just as common in horses as it is in the human population.

A University of Nottingham study found that at least one in five leisure horses was overweight or obese. Owners were likely to underestimate body condition score.

Veterinary student Helen Stephenson assessed the prevalence of obesity among horses whose owners were registered with an equine veterinary practice.

Questionnaires were sent to five hundred horse owners, and 160 were returned. None of the horses was kept for breeding, livery, riding stables, or competition, so all were classed as being used for leisure only.

One in five owners indicated that their horses were either overweight or obese.

The owners were asked about their perceptions of their horses’ body condition, and asked to score this from zero to five, with a score of more than three indicating overweight.

The researchers then assessed the body condition of 15 randomly selected horses to see if the owners had under or overestimated the horse’s weight.

They assigned an average score that was significantly higher for these horses; eight of the owners had scored their horse at least one grade lower than the researcher had, indicating that the owners had underestimated their horses’ weight.

Based on the researchers’ findings, the authors estimate that the true prevalence of overweight/obesity was likely to be 54% rather than the 20% indicated by the questionnaire responses.

Read more at www.equinescienceupdate.com/obeng.html

Feral horse survival under changing environmental conditions

Australia´s recent heavy rain presents an opportunity to examine how feral horses are affected by the weather.
 
Magdalena Zabek has been working with the Australian Brumby Research Unit (ABRU), keeping a photographic record of their work. Now she is looking to complete a study of her own into the effect of a period of plentiful rainfall on the feral horses of central Australia (“brumbies”) following nine years of severe drought.
  
Currently the brumby population is estimated to grow at around 20% annually. It seems likely that the foaling rate in 2011 will be higher, due to the more favourable conditions during the 2010 breeding season.
 
In the ABRU December 2010 newsletter, she writes: "Information from this study will provide valuable information about fluctuations in numbers of feral horses due to the changes in availability of food and water, which is crucial knowledge when implementing population control methods. The study will also contribute to the development of better welfare outcomes for feral horses."
 
"The sudden increase in numbers will have an enormous impact on the feral population when the favourable climatic conditions change because the fragile semi-arid ecosystem is not able to meet the food and water requirements of feral animals during periods of less favourable conditions. When resources become scarce due to drought, the feral horses are forced to travel ever increasing distances to obtain adequate food and water, and, as a result, may die."
 
The findings of the study should help direct strategies used to manage feral horses, and hopefully reduce suffering and death during periods of drought.

Read more in the ABRU December 2010 newsletter.
http://www.wildhorseresearch.com/Documents/Newsletters/December%202010.pdf
 
For more information about Magdalena´s art work see:
http://www.magdalenas-art-work.22web.net