Archaeologists find earliest metal bit

Excavation of a burial site in southern Israel, has unearthed what is believed to be the earliest known metal bit.

Archaeologists led by Professor Eliezer Oren from Ben Gurion University excavated an equid burial at Tel-Haror, an archaeological site with strata dating to the Middle Bronze IIB Period (1,750-1,650 B.C.). Among the bones they found a metal equestrian bit.

Dr. Joel Klenck, a Harvard University educated archaeologist and president of the Paleontological Research Corporation specialises in the analysis of animal remains. He identified the equid as a donkey by the shape and size of its pedal bones and traits on the grinding surfaces of its teeth.

Klenck points out that the donkey burial at Tel Haror is special since it provides the earliest direct evidence of a metal equestrian bit. He states, “Until the excavation at Tel Haror, archaeologists had only indirect evidence for the use of bits. An example of this indirect evidence is wear marks on equid teeth at the fortress of Buhen in contexts dating to the twentieth century B.C. At Tel Haror, we retrieved the actual metal device.”

He notes the ancient bit caused equids to turn due to the force of the device. Also, round plates on either end of the ancient bit exhibit triangular spikes that pressured the lips if the reins were pulled from one direction.

Read more at equinescienceupdate.com

 

How the zebra got its stripes

Why does the zebra have stripes? Perhaps they provide camouflage in the African savannah; perhaps they break up the animal's outline making it more difficult for predators such as lions.

However, research published recently in the Journal of Experimental Biology suggests that the stripes may confer protection against a different sort of predator.

An international team of scientists, led by Gábor Horváth of the Eötvös University, Hungary, found that the zebra's stripes help ward off biting flies.

Such flies are widespread in Africa, and, as well as spreading disease, they cause annoyance and disrupt grazing.

According to Horváth, these insects are guided to a wet habitat suitable for breeding by homing in on horizontally polarized light, which results when light is reflected off water. However, blood-sucking female flies also locate their victims by following polarized light reflected from their skin.

The research, carried out in Hungary, showed that a horse model with zebra stripes attracted far fewer horseflies (tabanids) than did homogeneous black, brown, grey or white equivalents.

The research team found that as the width of the stripes decreased the horseflies were less attracted. They also found that the width of the stripes on zebras coats fell within the range that was most disruptive to these biting flies.

“Tabanids have been shown to respond strongly to linearly polarized light,” they explain “and we demonstrate here that the light and dark stripes of a zebra’s coat reflect very different polarizations of light in a way that disrupts the attractiveness to tabanids.”

It appears to be the polarisation of the reflected light, rather than the colour , that is significant. The research team found that even on homogeneous grey surfaces the attractiveness to tabanids was reduced if the surface had bands of alternating polarisation.

“We conclude that zebras have evolved a coat pattern in which the stripes are narrow enough to ensure minimum attractiveness to tabanid flies”, says the team. They add, “The selection pressure for striped coat patterns as a response to blood-sucking dipteran parasites is probably high in this region [Africa]”.

Welfare implications of restrictive nosebands

Horse welfare at the Olympic Games is threatened if current trends are allowed to continue, according to the International Society for Equitation Science (ISES). The Society maintains that the practice of over tightening nosebands to avoid penalties in competition is covering up poor training at the expense of horse welfare.

ISES notes that, in the last few decades, there has been a steady increase in the design of nosebands that effectively mask evidence of a horse’s discomfort.

The incentives for athletes to over-tighten nosebands arise from the rules of dressage that penalize displays of discomfort such as open mouths and lolling tongues. These rules were written by the sport’s governing bodies to promote excellent training and the demonstration of qualities such as freedom, harmony, lightness and acceptance of the bit without tension. Restrictive tight nosebands can prevent the horse from displaying unwanted behaviours such as opening, gaping or crossing the jaw, and are enabling competitors to mask signs of tension which judges should penalise as evidence of inferior training. Thus nosebands may hinder effective judging.

Recent research*, by Professor Paul McGreevy and others, suggests that horses wearing tight nosebands undergo a physiological stress response, are sensitized to bit pressure and may have reduced blood flow with potential to cause injuries and tissue damage including nasal bone deformities, even when padding accompanies the noseband such as in the case of so-called crank nosebands.

ISES recommends:

• a return to the established practice of placing “two fingers” under the noseband to demonstrate that it has not been over-tightened. This amount of space under the noseband allows horses to express tension or seek relief from the pressure of the bit and so aligns with the principles of ethical equitation.

• that, for fairness and objectivity, a standard taper gauge should be used by stewards at competition. The taper gauge should be placed without force at the nasal midline and be clearly marked to show the desired stop, which, in alignment with established industry guidance, should be the dimensions of two average adult fingers.

Read more at equinescienceupdate.com

Help sought for Cushing's disease research

Cushing's disease (equine pituitary pars intermedia dysfunction - PPID) appears to be becoming more common as horses live longer. While the true incidence of this disease is unknown, a recent survey of horse owners showed that signs of Cushing's disease were reported in 20 to 30 per cent of horses.

Researchers at the Western College of Veterinary Medicine (WCVM), University of Saskatchewan, are starting to explore a possible new treatment for the condition.To learn more about the incidence and prevalence of Cushing's disease, WCVM equine specialist Dr. James Carmalt has designed an online survey that will be distributed to equine practitioners around the world. Dr. Carmalt and his colleagues at the western Canadian veterinary college will use practitioners' responses from this short, 16-question survey to:

• determine the incidence of disease

• determine the most common treatment protocols being used by practitioners

• evaluate the need for developing new treatment methodologies.

Owners whose horses have been diagnosed with Cushing's disease are urged to bring the survey to the attention of their veterinarian.

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

Many horses still too fat after winter

 

In the past, horses would lose condition over the winter, start the year in lean condition and gradually recover over the grazing season.

However, a recent survey of groups of horses spending at least six hours out at pasture has shown that more than a quarter were obese at the end of the winter months. 

This alarming trend may suggest that well-meaning winter management strategies such as rugging and a reduction in exercise could be having a detrimental impact on the welfare of horses in the United Kingdom.

The research was conducted by Sarah Giles, Dr Sean Rands and Professor Christine Nicol of the University of Bristol's Animal Welfare and Behaviour Research Group, in collaboration with the WALTHAM^® Equine Studies Group, headed by Professsor Pat Harris. They examined the variations in body condition in small groups of horses during the month of February 2011.

A cross sectional study of 127 horses and ponies was carried out in Somerset . Horses were kept in herds of three or more, and were at grass for at least six hours a day. Their condition was assessed using the nine point body condition score (BCS) system and the five point cresty neck score (CNS). The prevalence of obesity (BCS of 7 or above) was 27.6% with a slightly higher incidence in horses, while the prevalence of cresty neck (CNS of 3 or above) was 48.8% with a higher number of ponies affected.

Read more at www.equinescienceupdate.com

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