Improved strangles tracking

Strangles is one of the most commonly diagnosed infectious diseases of horses. Infection results in significant health and welfare consequences and economic costs. Most affected horses recover, however about 10% remain as carriers, free of clinical signs but capable of spreading the disease.

In the largest ever study of its kind into an equine pathogen, scientists in 18 countries used the latest DNA sequencing techniques to track the bacteria Streptococcus equi as it caused the disease strangles in horses around the world.

 

They analysed data on 670 Streptococcus equi isolates that had been recovered from 19 different countries. 

 

“Using standard diagnostic testing, the Streptococcus equi strains look almost identical, however by carefully examining the DNA of the bacteria, we have been able to track different variants as they spread across the world” said Prof. Matthew Holden of the University of St Andrews. “Piecing the puzzle together, we showed that cases in Argentina, the United Kingdom and the United Arab Emirates were closely linked. Along with other examples, we provide evidence that the global trade and movement of horses is helping to spread the disease.”

 

“Building on top of the data generated, we provide an online surveillance platform for strangles enabling labs to upload and interpret their genomic and epidemiological data in close to real-time. Pathogenwatch will be used to monitor the emergence and spread of new lineages to help inform interventions and policy making decisions” said Prof David Aanensen of The Centre for Genomic Pathogen Surveillance, University of Oxford.

 

The work, is published in the journal Microbial Genomics.

 

The authors urge that the World Organisation for Animal Health (OIE) recognise the international importance of strangles. They suggest that identifying horses that are infected with S equi before or immediately after transportation would yield significant benefits

 

“This has been an incredible team effort, which was only possible through the collaboration of leading researchers from twenty-nine different scientific institutes in eighteen countries” said Dr. Andrew Waller of Intervacc AB. “Horses are transported all over the world as they move to new premises or attend competitions and events. New cases of strangles can be prevented by treating carriers before they pass on the bacteria. This new research in the field of strangles and the new online Pathogenwatch resource provide an opportunity to track the course of infections, reigning-in Streptococcus equi’s globetrotting lifestyle by shutting the stable door before this horse pathogen has bolted!”

 

For more details, see:

 

DNA investigation highlights the ‘unbridled globetrotting’ of the Strangles pathogen in horses 

Microbial genetics (2021)

https://doi.org/10.1099/mgen.0.000528

New strain of deadly Hendra virus discovered

The Australian veterinarian-led research project, ‘Horses as Sentinels,’ has identified a new strain of the deadly Hendra virus (HeV) as the cause of a previously unexplained horse death.

Hendra virus is highly lethal in both horses and humans, with mortality rates approximately 79% and 60% respectively. The originally recognised strain of Hendra virus has resulted in the deaths of four humans and over 100 horses in Australia, since 1994. 

 

Hendra virus was first identified in 1994 when racehorse trainer Vic Rail died after suffering a mysterious pneumonia like illness when 20 racehorses in Hendra, Queensland, also died. Subsequently, a previously-unknown virus was identified as the cause of both the trainer’s and the horses’ deaths. 

 

The attending veterinarian was Dr Peter Reid. Nineteen years later, Dr Reid teamed up with Dr Annand – a veterinarian involved in the discovery of Australian bat lyssavirus in horses in 2013, and Dr Ina Smith of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Risk Evaluation and Preparedness Program to launch the ‘Horses as Sentinels’ project. The research team now also includes collaborators from around Australia and the United States.

 

Flying foxes (fruit bats) are known to spread the virus. The original strain of Hendra virus has been found within the range of black flying foxes and spectacled flying foxes. However, the new HeV variant has also been isolated from Grey-headed flying foxes. This species migrates, and their range includes parts of southern Australia that have so far been considered to be at low risk of Hendra virus in horses and people.

 

The finding indicates that HeV should be considered as a possible diagnosis in unvaccinated horses anywhere in Australia that flying foxes are present, and that unwell, suspect horses which return an initial negative Hendra virus test should continue to be treated with the same caution as a Hendra virus positive case, until testing for the new variant is performed. 

 

The ‘Horses as Sentinels’ research team has developed updated diagnostic laboratory techniques capable of identifying the new strain, and will be sharing them with relevant laboratories. They have also established that the current Hendra virus horse vaccine is expected to be equally effective against the new strain.

 

For more details, see:

https://www.vetvoice.com.au/media-releases/new-strain-of-deadly-hendra-virus-hev-discovered/

Impending worming crisis

 

We are heading for anthelmintic resistance disaster unless we radically change our ways according to a group of scientists and clinicians. In a letter to the Veterinary Record, David Rendle and others of the British Equine Veterinary Association (BEVA) anthelmintic working group report the findings of a small-scale survey into the use of faecal worm egg counts (FWECs) and anthelmintic sales.

The seriousness of the problem is highlighted by the fact that resistance to all currently available classes of anthelmintics has been reported in both the cyathostomins (small redworm) and ascarids (large roundworm). Furthermore, there is currently no prospect of new drugs in the pipeline.

The BEVA working group collected data on faecal worm egg counts performed and the sales of anthelmintic doses in the United Kingdom from 2015 to 2018

They found that the number of FWECs performed increased by 29% (from 91,769 in 2015, to 119,030 in 2018).

The number of horse doses of anthelmintic fell by 2.9% over the same period.  from 1,166,053 in 2015 to 1,131,759 in 2018 (In fact falling by 8% between 2015 and 2016, before gradually increasing each year after that)

Although it is encouraging that the number of FWEC tests performed has increased, the authors express concern at the low number of tests relative to the number of doses sold, and the increase in anthelmintic sales between 2016 and 2018.

They point out that if current guidelines were followed, and anthelmintic treatment only carried out when shown to be necessary by a FWEC, then there should be at least twice as many FWECs than anthelmintic doses. But the data showed that only one FWEC was carried out for every 11 doses sold.

They were also concerned that sales of the macrocyclic lactone moxidectin remained high throughout the four years. This was despite “despite universal consensus by experts that it should not be used as a routine treatment.”

They conclude: “If a crisis in equine welfare is to be averted, then a paradigm shift in attitudes to anthelmintic use and a radical change in the availability of anthelmintics will be required.”

Fore more details, see:

Anthelmintic resistance in equids

D Rendle and others. 

Vet Record (2021)188, 230

New research into Equine Grass Sickness

Vets and horse owners across the UK are invited to help in a new research effort to find out more about Equine Grass Sickness (EGS). The disease remains stubbornly resistant to attempts to understand its cause.

Grass Sickness remains a major cause of mortality in horses and ponies in Britain with more than 80% of cases proving fatal. Some chronic cases do survive with specialised intensive nursing.

The Moredun Foundation and the Equine Grass Sickness Fund have embarked on an ambitious five-year plan to reveal the mysteries of this deadly disease.

They will continue to investigate the existing suspects, including mycotoxins and clostridium botulinum, but will also review all the research done to date, to see what might have been missed, or what new angles or techniques they might be able to uncover. For the first time several research projects will be ongoing simultaneously, bringing scientists, vets and horse owners together in an unprecedented collaboration to discover the cause.

As part of the plan, an EGS Fellowship Project will collect information on cases of grass sickness to form a national EGS Biobank. The new research Fellow will be based at the Moredun Research Institute and will spearhead the development of a new database and sample biobank to enable research to progress and encourage new thinking and inter-disciplinary collaborations.

Horse owners are being encouraged to take part in the project by becoming “EGS detectives” to raise awareness about the disease in their area, helping to report cases and submit samples for the research biobank.

Researchers want to collect samples from affected horses and from unaffected ones grazing the same pasture. They also aim to collect samples from the affected horses’ environment – including soil, herbage and water.  Additional information about the horse and pasture will be collected through a questionnaire.

It is hoped that the information will help identify the underlying causes of the disease or the factors that trigger its onset.

Professor Lee Innes, Moredun Research Institute said, “We are delighted to be launching this new research initiative bringing together horse owners and researchers to progress our knowledge and understanding of this devastating disease. Moredun has a long and proud history of working in close collaboration with livestock farmers to help develop solutions to combat disease and we are keen to apply this model of collaboration to help tackle equine grass sickness”.

For more details go to:

https://grasssickness.org.uk/research/egs-biobank-horse-owner-information/

Vets with Horsepower 2021

Since 2010 the Vets with Horsepower team have been raising funds for charities in their own inimitable style – travelling the world on motorbikes and delivering high quality education to vets and owners. Last year’s trip fell victim to COVID-19. Not to be thwarted this year they have planned a record-breaking marathon of CPD lectures on equine veterinary topics to be delivered over 25 hours non-stop on 29th April.

Registration is in return for a donation which goes to support their chosen charities. They explain:

“Since spring of 2020, we have not been able to raise funds for charities in our usual, slightly crazy way. However, charities do struggle, and need money now more than ever. If you can, please donate today, all funds raised will go directly to our fantastic charities:

• “Ethelberth Youth and Childcare centre in South Africa. Over the years the Vets with Horsepower team have provided support for Ethelbert children's home and youth care centre in South Africa. This fantastic charity looks after children in their time of need and provides them with a safe home away from home so they are able to continue their education and look ahead to a bright future if and when they are reunited with their families.

• “The Gambia Horse and Donkey Trust. Providing veterinary care to working animals and education for the families that rely on them. With our help, they have built a veterinary clinic and have modified a van into an ambulance, essential to carry the horses and donkeys with more severe injuries to the clinic for treatment.

• “Saving the Survivors works with helping the victims of poaching attacks – such as rhino, elephant, wild dog, cheetah and pangolin.

• “Vetlife, a UK based charity for the veterinary community. Their aim is to provide support to members of the UK veterinary community and their families who have emotional, health or financial concerns, whilst seeking ways to prevent such situations in the future. The veterinary community continues to experience significantly higher levels of depression and suicide than the general population.”

For more details, and to donate and register go to:

https://www.vetswithhorsepower.com/2021.html

The Vets with Horsepower team point out that every penny raised via sponsorship, donations and sold CPD tickets is going to amazing charity work. They support projects that are making a difference to humans or other animals, are achievable, where success can be demonstrated and that would not have been possible without their help.

You can read more about the charities here: https://www.vetswithhorsepower.com/charities.html

Chance to help Equine Cushing's research

 

Horse owners and carers can help research into the underlying causes of Pituitary Pars Intermedia Dysfunction (PPID) also known as Equine Cushing’s Disease, a condition common in older horses and ponies. Typical signs include a long curly hair coat and weight loss. The condition is associated with a range of problems the most serious of which is laminitis. 

Researchers at the University of Melbourne are conducting a survey of horse owners as part of a broader, major international project to improve the understanding and knowledge of the fundamental causes of the condition, in order to improve early diagnosis, treatment, husbandry and nutritional management.

 

The short online survey is designed to better understand how owners manage horses or ponies with PPID, and what the important factors are for them including: the ability to feed separately and cost of medications.

 

Lead researcher at the Melbourne Veterinary School, Dr Nicolas Galinelli said that it was important to gain a better understanding of current management practices when it comes to PPID. 

 

“We need to get a broader sense of what is working for horse owners so that we can improve health outcomes for these animals both in terms of the early recognition of PPID signs and in the way we determine the most appropriate treatment, management and nutrition.”

 

“PPID affects approximately 20 per cent of horses and is slightly more common in ponies. Sometimes it is treated with specific drugs that target the excessive production of hormones from the pituitary gland, whilst other owners may choose to only treat the clinical signs of the disease such as laminitis. Adapting the diet can also be helpful. We want to understand how owners make treatment decisions and which decisions are having the best outcomes,” Dr Galinelli said.

 

Veterinary pharmacology expert, Professor Simon Bailey added that the survey will ask owners about what factors are important for them in treating PPID, including the cost and side-effects of medications and the ability for horses to be fed separately. He said “We encourage owners to get in touch once our results have been finalised and published. We are keen to help share this information with the equine community and thank them for their support.” 

 

The research, supported by the Australian Research Council, is being undertaken by the Melbourne Veterinary School and Queensland University of Technology with industry partners including WALTHAM Petcare Science Institute (UK), Boehringer Ingelheim (Germany) and The Liphook Equine Hospital (UK).

 

The results from this anonymous survey will provide valuable information and contribute to improved targeted education of the horse owning public.

 

To complete the survey, go to:

 

https://melbourneuni.au1.qualtrics.com/jfe/form/SV_0GPNcsoVqyB6lo2

Reducing deworming frequency without adverse health effects

Less intensive deworming strategies appear as effective in preventing disease as traditional more frequent treatment regimes

With the increasing problem of anthelmintic resistance, we are urged to adopt a more sustainable approach to deworming.

A study led by Martin Nielsen monitored egg count levels, bodyweight and equine health in mares and foals under different parasite control regimes. A report of the work has been published in the Equine Veterinary Journal.

Ninety-three foals and ninety-nine mares at two Standardbred and two Thoroughbred stud farms were included in the study. Faecal samples and bodyweight were monitored monthly, and any occurrence of colic or diarrhoea was recorded.

The foals were divided into two groups and wormed either monthly or on two occasions at two and five months of age. Mares were split into three groups and wormed monthly, twice a year, or when faecal egg counts exceeded 300 eggs per gram.

The research showed that, compared to foals treated monthly, foals dewormed at two and five months old had significantly higher strongyle and ascarid faecal egg counts. Despite that, there was no significant difference in body weight between the two groups.

Mares wormed twice a year weighed less than those in either of the other groups. However, there was no significant difference in faecal egg counts between the groups. 

The authors conclude that it was possible to reduce the frequency of anthelmintic treatment from traditional high intensity regimes without apparent negative health consequences.

Martin Nielsen has published a video summary of the work, which is available at:

https://vimeo.com/483033105

 

 

For more details, see:

Monitoring equine ascarid and cyathostomin parasites: Evaluating health parameters under different treatment regimens
Martin K. Nielsen, Erica K. Gee, Alyse Hansen, Tania Waghorn, Julie Bell, Dave M. Leathwick
Equine Veterinary Journal (2020)

https://doi.org/10.1111/evj.13374

Research funding announced

The Grayson-Jockey Club Research Foundation has announced funding of $1,638,434 towards 12 new projects, 12 continuing projects, and two career development awards each worth $20,000. 

New studies being supported this year include:

 

“Passive immunization of foals with RNA-AB against R equi.” Led by Jeroen Pollet, the project at Baylor College of Medicine will follow on from previous work that showed that poly-N-acetyl glucosamine (PNAG) anttibodies can protect foals against Rhodococcus equi (R. equi) infection. 

 

Currently, these protective antibodies can be acquired by foals drinking çolostrum from a vaccinated mare or by a blood transfusion. But now the research team want to develop a new vaccine to give newborn foals instant protection against R equi infection. 

 

They explain that the vaccine comprises lab-made messenger RNA molecules (mRNA), which are a blueprint that can be used to instruct cells to produce protective PNAG binding antibodies. “We intend to administer the mRNA therapy by using a nebulizer, to let the foals inhale the RNA. This way, we hope to make the procedure less invasive and have mRNA delivered to lung cells where the antibodies are most needed for protection against R. equi. The proposed project would be the first study developing an mRNA therapy for horses.”

 

A University of Minnesota project led by Molly McCue aims to use resting electrocardiograms (ECGs) to identify horses with irregular heart rhythms at exercise that can cause sudden cardiac death (SCD.  They anticipate that this should allow increased monitoring and improved understanding of SCD. 

 

Thomas Koch, at the University of Guelph, has gained funding for research that will assess the use of equine umbilical cord blood-derived mesenchymal stromal cells to treat joint injuries in horses. 

 

A Texas A&M University study led by Noah Cohen will look at developing a more accurate blood test to identify horses infected with the Streptococcus equi to improve control and prevention of strangles. 

 

Further details of these and all the other projects supported by this year’s Grayson Jockey Club research grants are available at:

 

http://www.grayson-jockeyclub.org/default.asp?section=2&area=Research&menu=2

Potential role of asthma in DDSP?

Upper respiratory tract conditions have received much attention in the causation and treatment of
dorsal displacement of the soft palate (DDSP). Recent research highlights the potential role played by lower airway conditions.

A study in Hungary has found DDSP was common in sport and pleasure horses with equine asthma.

In the normal horse, the soft palate fits snugly around the base of the epiglottis (the front part of the larynx). This allows inhaled air to pass directly from the nasal passages into the trachea. Normally, the horse does not breathe through the mouth.

Dorsal displacement of the soft palate occurs when the soft palate becomes dislodged from its normal position and comes to rest on top of the epiglottis, in the laryngeal opening. When this occurs during high-speed exercise, the high air flow causes the free border of the soft palate to vibrate. This causes significant obstruction to the horse’s breathing and produces a gurgling sound. The horse usually has to slow down and swallow to replace the soft palate in its normal position.

A study by Kinga Joó at the Szent István University, Kaposvár, Hungary and colleagues, reviewed the findings of pleasure and sport horses (competing at national level) presented for evaluation of suspected equine asthma.

Clinical examination of the horses included endoscopic examination, both at rest and during exercise. Tracheal wash and bronchoalveolar lavage (BAL) were used to collect mucus from the trachea and lower airway.

During the resting examination, a nasal occlusion test was performed to mimic pressure changes that might occur during intense exercise. In many horses this caused the palate to displace.

In all, 22 mild/moderate and 31 severe asthmatic cases were included in the study, a full report of which is published in the Journal of Equine Veterinary Science.

The authors found that 65% of pleasure and sport horses with mild equine asthma showed DDSP during the nasal occlusion test. In horses with severe equine asthma, 79% showed DDSP at rest and all of them had DDSP at exercise.

Horses showing DDSP tended to cough but did not make the typical gurgling sound heard in racehorses. The authors suggest this may be because of the lower rate of air flow in these horses compared with racehorses.

They emphasise the importance of treating the upper and lower respiratory tracts as a single unit, “as lower respiratory tract diseases can often cause upper respiratory functional disorders, whereas upper respiratory obstructions could be a factor in lower respiratory problems.”

They suggest that treatment of dorsal displacement of the soft palate has to be tailored to the cause.

For more details, see:

Asthmatic Disease as an Underlying Cause of Dorsal Displacement of the Soft Palate in Horses
Kinga Joó, Ágnes Povázsai, Zsófia Nyerges-Bohák, Ottó Szenci, Orsolya Kutasi
J Equine Vet Sci (2021) 96:103308.
 doi:10.1016/j.jevs.2020.103308.

Does omeprazole reduce side effects of phenylbutazone?

The authors of a recent report warn of risks associated with administering phenylbutazone and
omeprazole together.

Phenylbutazone, a non-steroidal anti-inflammatory drug (NSAID), is widely used in horses to treat lameness and other inflammatory conditions. It may cause adverse effects including kidney damage, and ulceration of the stomach and large intestine. To reduce the risk of these side effects, some clinicians have been administering omeprazole at the same time.

Omeprazole, is a proton-pump inhibitor that has been shown to be effective in preventing and treating equine gastric ulcer syndrome (EGUS). Similar drugs have been used in human medicine to treat and prevent NSAID-induced mucosal damage.

A study by Megan Ricord and others at Louisiana State University School of Veterinary Medicine at Baton Rouge, investigated the benefit of giving omeprazole at the same time as phenylbutazone in horses.

Horses from the University’s teaching herd with mild (<grade 2) gastric ulcers (involving either gastric (EGGD) or squamous (ESGD) mucosa) were involved in the study. They were divided into three groups and received a paste containing phenylbutazone (PBZ), phenylbutazone and omeprazole (PBZ/OME) or an inert control.

Horses were withdrawn from the study if adverse effects (colic, lethargy, diarrhoea) were identified that required medical management, or if ulceration (EGGD or ESGD) greater than grade 4 was seen.

The research team found that omeprazole did reduce EGGD formation, but did not influence development of ESGD.  The PBZ-treated group also showed a decrease in plasma protein concentrations compared to controls, which was likely associated with inflammation of the colon.

More intestinal complications occurred in the PBZ/OME group. These were mostly impactions, but two horses died and on post mortem examination they were found to have intestinal inflammation, ulceration and necrosis. 

The horses usually lived outside, but were housed for the duration of the study and this may have influenced the outcome. However, as the researchers point out, horses receiving non-steroidal treatment are often housed because of lameness issues.

“Importantly,” they point out, “concurrent administration of phenylbutazone and omeprazole, in association with change in management, led to an increase in clinical signs of intestinal complications.”

They advise that caution should be exercised when co‐prescribing phenylbutazone and omeprazole in horses.

For more details, see:

Impact of concurrent treatment with omeprazole on phenylbutazone-induced equine gastric ulcer syndrome (EGUS)
Megan Ricord, Frank M Andrews, Francisco J M Yñiguez, Michael Keowen, Frank Garza Jr, Linda Paul, Ann Chapman, Heidi E Banse
Equine Vet J (2021) 53:356-363.

doi:10.1111/evj.13323.

Online equine health talks

An online series of equine health seminars for Western Canada's horse community, is to be hosted by the Western College of Veterinary Medicine (WCVM)

Topics to be covered include Equine Asthma, foal care, cardiology, EMS and PPID and gastric ulcers. Talks take place on alternate Tuesday evenings starting February 23.

Although there is no charge, you need to register beforehand.

For more details, see:

https://wcvm.usask.ca/education/equine-seminars.php

Assessing welfare in working equids

Brooke, the international working horse and donkey charity, has unveiled an online collection of animal welfare indicators.

Their website explains: “Animal welfare indicators are scientific, non-invasive measurements of aspects that contribute to an animal’s overall welfare state, which help us to understand welfare from the animal’s perspective and include physical measures such as nasal discharge or body lesions, and behavioural measures, such as the animal’s response to contact or general attitude.”

Brooke introduced their first Working Equine Welfare Assessment protocol in 2003. Since then, they have refined how they assess animal welfare in the field.  In 2011, this resulted in them launching their Standardised Equine-Based Welfare Assessment Tool (SEBWAT), which is still widely used in their international country programmes with working equids.

Ashleigh Brown, global animal welfare advisor at Brooke, said: “Brooke benefits from many years of experience in assessing animal welfare in the field, in numerous countries around the world. We are excited to be able to share our resources and our learning to support others with their efforts to measure and improve animal welfare.”

Brooke hopes that the welfare indicators will be useful for scientists assessing welfare within a research context, animal health practitioners and veterinarians treating equids, and students of animal welfare assessment, equine science or animal welfare science. The tools may also be used to monitor the impact of welfare related regulation and provide welfare data in support of animal advocacy and welfare campaigns.

For more information and to access the repository, visit the Brooke website:

https://animalwelfareindicators.thebrooke.org

Strongylus vulgaris implicated in peritonitis?

Strongylus vulgaris (commonly known as the blood worm) used to be a common cause of colic before the advent of ivermectin, which proved to be very effective against the parasite. The larvae migrate up the arteries supplying the intestines, causing damage as they go. This can lead to thrombus formation and ischaemic damage, typically involving the large intestine.

Anthelmintic resistance, particularly among the cyathostomins (small red worms), has led to reduced use of anthelmintics. In some countries, including Sweden, anthelmintics have been restricted to use on prescription only.  There is concern that this may be allowing Strongylus vulgaris to make a comeback.

What is the current relationship between gastrointestinal parasites and colic? Research has been carried out at the Swedish University of Agricultural Sciences, in Uppsala, Sweden. The work, by Ylva Hedberg-Alm and colleagues, is published in the journal Animals (Basel).

Blood and faecal samples were collected from horses presented to the Horse Clinic, at the University Animal Hospital. Each horse with a gastro-intestinal condition (colic, colitis, peritonitis, weight loss) was matched with a control horse of similar age seen during the same week for a condition unrelated to the gastrointestinal tract. The owners were questioned about management and history

The findings were compared between those presenting with colic and those with problems unrelated to colic. A total of 137 cases and 137 controls were included in the study. Age and gender distribution was similar between the groups.

Faecal samples were examined for strongyle egg counts, and for Anoplocephala perfoliata (tapeworm) eggs. The presence of S. vulgaris was confirmed using a polymerase chain reaction (PCR) test. (S. vulgaris eggs look like those of other strongyles, including the more common cyathostomins.)

Blood samples were evaluated for antibodies to S. vulgaris using an ELISA test.

The researchers found that exposure of Swedish horses to S. vulgaris was common. Most horses, both cases and controls, were positive in the S. vulgaris ELISA test. In addition, horses with peritonitis had significantly higher ELISA values compared to controls and to other gastrointestinal diagnoses, suggesting S. vulgaris was involved in this case group. 

They also found that despite new legislation, 29% of owners did not use faecal analyses to monitor the parasite burden. The use of additional methods to diagnose specific parasites, such as S. vulgaris, was low. Owners rarely used pasture management methods to reduce the parasite burden on the grazing.

The authors suggest that, considering exposure to S. vulgaris appears high, there is a need for education in specific faecal diagnostics and pasture management. 

 

For more details, see:

Parasite Occurrence and Parasite Management in Swedish Horses Presenting with Gastrointestinal Disease—A Case–Control Study
Ylva Hedberg-Alm, Johanna Penell, Miia Riihimäki, Eva Osterman-Lind, Martin K. Nielsen, and Eva Tydén
Animals (Basel). 2020 Apr; 10(4): 638. 
doi: 10.3390/ani10040638

Causes of contracted heels investigated

A recent study found that heel contraction was more common in shod than in barefoot horses, but did not confirm that metal horseshoes were to blame.

Contracted heels have been defined by the ratio of frog length to frog width. The foot can be described as contracted when the frog width is less than 2/3rds its length. The affected foot is less able to absorb concussion and may lead to lameness.

Magdalena Senderska-Płonowska, with colleagues at the Wroclaw University of Environmental and Life

Sciences, Wrocław, Poland, assessed the influence of shoeing and other risk factors, such as age, access to paddock, and breed, on heel contraction.

The 114 horses included in the study were of various warmblood  breeds, and were being used as riding-school horses, pleasure horses, and sport horses. They were considered to be sound by their owners or riders, were at least three years old, and came from yards across Poland.

One group had been kept barefoot all their lives; the others had been regularly shod with metal shoes for at least the previous year.

Dr Senderska-Płonowska measured the width and length of the frog of all four feet of the horses in the study. She found that individual horse features, such as yard and breed, had the most significant impact on the width:length ratio of the frog.

There was a significant difference in occurrence of heel contraction between yards. Breed was also an important factor. Silesian and Arabian horses had significantly greater frog width: length ratio compared with other breeds.

Being shod did not affect the frog width: length ratio.

A full report of the research is published in the Journal of Equine Veterinary Science. Senderska-Płonowska concludes: “heel contraction is a multifactorial problem, mainly caused by breed and unknown features correlated with the individual. The results disputed the popular myth of metal shoes being main cause of contraction, an important factor for all hoof-care providers to be aware of. “

Because of the significant difference in incidence of contraction between yards, she suggests the need for more research on larger groups of well-defined phenotypes of horses from yards with low and high incidence of heel contraction to identify the environmental factors responsible.

For more details, see:

Do Metal Shoes Contract Heels? - A Retrospective Study on 114 Horses
Magdalena Senderska-Płonowska, Paulina Zielińska, Agnieszka Żak, Tadeusz Stefaniak
J Equine Vet Sci (2020) 95:103293.
https://doi.org/10.1016/j.jevs.2020.103293

Effect of light on wound healing

 Do light emitting diodes (LEDs) emitting infrared or red light help wound healing?

 Research conducted at the Swedish University of Agricultural Science, Uppsala, Sweden looked at the effect of pulsating visible red light (wavelength 637nm) and near infrared light (NIR) (wavelength 956nm) on experimental skin wounds on horses.

 

Peter Michanek and colleagues used eight healthy adult standardbred horses in the randomised controlled study. The research team made a circular (2cm diameter) surgical skin wound on both sides of the neck of each horse.

 

The wound on one side was chosen at random to receive the light treatment. The opposite side was left untreated. Light therapy followed a standardised protocol and was given by the same operators throughout the study. Treatment was applied daily (comprising red light for 95 seconds and NIR light for 185 seconds) 5 days a week for 4 weeks. 

 

Wound healing was monitored by someone who did not know whether the wound had received light treatment or not.

 

The researchers found that the difference in wound area between treated and control wounds did not differ significantly at any stage of the study. It actually took longer for treated wounds to heal completely compared with the untreated wounds. The researchers point out that, although significant, the difference was small and probably not of clinical significance.

 

They conclude that, in this study, pulsating visible red light or NIR was no better than no treatment in promoting healing of experimental skin wounds.

 

For more details, see: 

 

Effect of infra-red and red monochromatic light on equine wound healing.

P Michanek, T Toth, E Bergström, H Treffenberg-Petterson, A Bergh.

Equine Vet J (20211) 53, 143

https://doi.org://10.1111/evj.13266

Factors influencing owners’ approach to horse care

How does the horse owner’s attitude towards horse ownership affect horse welfare?

Research from the University of Melbourne, Australia, examined the relationships between horse owner background factors (such as age, income, place of residence, knowledge and experience) and their attitudes towards horse husbandry and management behaviour.

Lead researcher Lauren M. Hemsworth, of the Animal Welfare Science Centre, in the Faculty of Veterinary and Agricultural Sciences, used a questionnaire to assess the owners’ attitude to horse ownership and management, together with an on-site inspection of horse husbandry and management on premises in Victoria, Australia. Data from 57 owners and 98 horses were included in the study.

She found relationships between horse owner background factors and the owners’ attitudes towards horse husbandry and management behaviour in areas such as parasite control, hoof care, and dental care. For example, favourable behavioural beliefs towards appropriate parasite control were associated with a young age and frequent riding instruction.

A full account of the work is published in the journal Animals.

The authors report that, “generally, belief variables correlated significantly with background factors that were primarily related to knowledge and experience. Further, beliefs concerning three key husbandry practices (parasite control, hoof care, and dental care) all appear to be predicted to some degree by background factors associated with knowledge and experience.”

So, they suggest that an educational strategy to improve the horse owner’s appreciation of the welfare implications of their behaviour may be important in safeguarding recreational horse welfare, but further research is warranted.

For more details, see:

The Human–Horse Relationship: Identifying the Antecedents of Horse Owner Attitudes towards Horse Husbandry and Management Behaviour. 
Lauren M. Hemsworth, Ellen C. Jongman and Grahame J. Coleman
Animals (2021),11, 278.

https://doi.org/10.3390/ani11020278

 

Stirrup safety research

If you have had a fall in the past 12 months, you are urged to take part in research on stirrup safety.

 

If you ride, then falls go with the territory. One aspect of falls and injuries that is often speculated about but to date has not been properly studied is the role that the stirrups play in safety or risk of injury.

 

Dr David Marlin, Cambridge (UK) and Dr Jane Williams, Hartpury University (UK) have set up a survey to collect data on recent falls (within the past 12 months). The aim is to try and understand what factors related to the stirrups may increase or reduce the risk of injury in riders.

 

The survey consists of 19 short questions and should take about 4 minutes to complete. No personal data will be collected.

 

To take part in the survey go to:

https://www.surveymonkey.co.uk/r/Stirrup_Survey_2020

US equine industry survey

 Horse owners in the United States are invited to take part in a survey looking at the US equine industry.

The survey aims to gauge participation trends and management practices in the U.S. equine industry. It also seeks to gather information regarding the most important issues facing the industry.

If you currently own or manage at least one horse, pony, mule or donkey, are 18 years of age or over, and live in the United States, you are eligible to participate. It is anticipated that the survey, which the promoters emphasize is anonymous, will take 15 minutes to complete.

Organized by American Horse Publications, a non-profit association, and sponsored by pharmaceutical company Zoetis, the survey is open until March 30, 2021.

For more details, go to:

https://www.surveymonkey.com/r/N9FPXFG

Medical Grade Honey prevents surgical site infections

Abdominal surgery is a major undertaking in horses, and not without significant risks to the patient. Colic operations, especially those that involve opening the gut wall, risk contaminating the wound with bacteria such that surgical site infection (SSI) is a potential complication.

Medical grade honey (MGH) has been used successfully to treat established infections in both humans and animals, and has been shown to improve wound healing of equine lacerations and significantly reduce infection rate.

 

Would the application of MGH help abdominal surgical wounds to heal?

 

A study by Gustafsson and colleagues investigated whether medical grade honey gel, applied on the linea alba during wound closure, would decrease the prevalence of incisional infections in horses undergoing colic surgery.

 

Figure 1: Example of intra-lesional application of
L-Mesitran Soft (MGH) following colic surgery

The linea alba is the fibrous band that runs along the midline of the belly, between the abdominal muscles.  Being composed of fibrous connective tissue it contains no major blood vessels making it a suitable site for incisions for abdominal surgery.

 

In this prospective randomized controlled trial, 108 horses that underwent colic surgery at Koret School of Veterinary Medicine in Israel were enrolled. Horses were randomized to control or treatment (MGH) group. In the treatment group, following closure of the linea alba, MGH gel (L-Mesitran Soft) was placed in the incision followed by routine closure of subcutaneous tissue and skin (Figure 1).

 

Horses were excluded from the study if they needed a second abdominal surgery (n=4) or did not survive for at least two weeks post-operatively (n=15).

 

The clinicians report that a single intra-incisional application of MGH gel strongly reduced incisional infection rate from 32.5% (13/40) in the control group to 8.2% (4/49) in the treatment group (p=0.02).

 

No adverse reactions were observed with the subcutaneous application of MGH after colic surgery.

 

A full report is published in the Equine Veterinary Journal.

 

The authors conclude that intra-incisional application of MGH gel on the linea alba is a simple and rapid procedure that was safe and did not result in any adverse effects. A single local prophylactic treatment with MGH in the abdominal incision during surgery significantly decreased the prevalence of incisional infections in horses undergoing colic surgery. They suggest that more research is necessary to explore this promising approach in indications outside the equine colic field, e.g., in surgeries with a high risk of SSIs.

 

For more details, see:

 

Intra‐incisional medical grade honey decreases the prevalence of incisional infection in horses undergoing colic surgery: a prospective randomised controlled study.

Gustafsson, K., Tatz, A.J., Slavin, R.A., Sutton, G.A., Dahan, R., Abu Ahmad, W. and Kelmer, G.

Equine Veterinary Journal (2020)

https://doi.org/10.1111/evj.13407

 

An interview with Dr Gustafsson is available on YouTube:

https://youtu.be/q2yf7a0f5Ds

Special interest webinars precede National Equine Forum

The National Equine Forum (NEF) will be delivered in a virtual format in 2021. The main Forum, on

Thursday 4^th March, will be preceded by two special interest webinars, to be held in January.

The first webinar “Just in Time – Using Science to Save our Breeds”, (7pm Wednesday 13th January 2021), will be delivered by industry leaders, with opportunities for discussion and questions from the audience.

Chaired by Prof Tim Morris, the webinar will include speakers: Tullis Matson, Simon Cooper, Paul Flynn and Andy Dell.

They will look at the magnitude of the decline of the UK’s native breeds and how their future can be safeguarded. The impact of the extinction vortex on the natural world and how it applies to equine breeds will be covered and the challenging situation of inbreeding in Thoroughbreds explored.

The advantages of DNA analysis will be debated, to show how science can provide breed societies and breeders with support to guide decisions that can increase effective populations. This will be endorsed with a case study to show proof of concept that breeds in decline have a chance to be saved when genomics and kinship analysis are utilised.

The second webinar “Great Weight Debate (equine)”, (7pm Wednesday 27th January 2021), will take a practical look at different perspectives on equine weight management, from across the equestrian sector, including the views of a horse owner, livery yard owner and coach, an equine welfare officer, an equine vet, a nutritionist and a competition judge.

The panel of speakers will aim to identify what is preventing owners/carers from managing horse weight effectively, despite many previous and ongoing attempts from industry to effect change. They will also explore how any obstacles may be overcome and the discussions will be supported by a human behaviour change researcher.

The 29th National Equine Forum, themed Positivity and Progress will be held on Thursday 4th March 2021. The morning session will provide critical insight to welfare, trade and biosecurity, followed by positive innovations for the sector, borne from Covid-19. The afternoon session will provide updates from the two special interest webinars, a session on how new technology is helping riders and a revisit to access and accidents, with amendments to The Highway Code.

Tickets are priced at £5.00 for each webinar and £10.00 for the Forum itself and there is no booking fee. Webinar tickets are available now. NEF tickets will be available in January.

For more details, see:

https://www.nationalequineforum.com/forum-2021/

CT best for identifying foot foreign bodies

 Puncture wounds at the coronary band or in the sole are not uncommon in horses.  Although the site of

the injury may be obvious, it is often less clear whether any foreign material remains buried in the wound.

Researchers at the Philip Leverhulme Equine Hospital, University of Liverpool, conducted a study to compare the value of different imaging techniques for identifying foreign bodies in horses’ feet.

Nadine Ogden and colleagues assessed the ability of three equine veterinarians, experienced in advanced imaging interpretation, to identify foreign bodies buried in the cadaver specimens of horses’ feet. They used five different materials: slate, glass, dry wood, soaked wood and plastic. Each foot had two different foreign bodies implanted, at the coronary band and in the sole.

Computed tomography (CT), magnetic resonance imaging (MRI) and digital radiography (DR) were used to obtain images, which were then examined by the clinicians.

The researchers found little variation between the clinicians studying the images. CT was the most useful imaging modality, having a higher visibility score, sensitivity/specificity, and interrater agreement for detection of all materials; particularly slate, glass, and dry wood, compared to the other imaging modalities.

They found that foreign bodies were often visible on MRI, although the images were generally not clear enough to determine the type of material involved. They also  found that even relatively large foreign bodies consisting of plastic or wood were not detectable on DR.

The work is published in Veterinary Radiology and Ultrasound. The authors comment that although it is not usually necessary to identify the specific material involved, it is important to select an appropriate imaging technique to detect the suspected foreign body.

They suggest that, in cases with negative findings on MRI and DR, where there is a suspected foreign body within the hoof, particularly in cases where plastic or wood fencing or glass materials have been found at the scene of injury, CT examination should be considered.

 

For more details, see:

CT more accurately detects foreign bodies within the equine foot than MRI or digital radiography

Nadine K E Ogden, Peter I Milner, John D Stack, Alison M Talbot

Vet Radiol Ultrasound (2020)

doi: 10.1111/vru.12944

Temperature monitoring with microchips

 Horses undertaking strenuous or prolonged exercise in hot and humid environments may produce heat

more quickly than they can lose it, putting them at risk of postexercise exertional heat illness.

 Investigations into heat production and cooling require a way to monitor body temperature. Ideally this should be easy and safe to do in an excitable horse after exercise.

 In practice, reading the rectal temperature with a thermometer is a common starting point – but may not be ideal, particularly if repeated readings in excited horses are required. The “gold standard” for monitoring is to record the central venous temperature (CVT) using a thermocouple introduced into the jugular vein.  

 Temperature sensitive microchips (percutaneous thermal sensing microchip (PTSM)) can be used to measure tissue temperature in a non-invasive manner. But does the site of implantation affect the accuracy?

 Researchers at the School of Agriculture and Food Sciences, and the School of Veterinary Science, at the University of Queensland, investigated the use of PTSMs for monitoring temperature in horses after strenuous exercise.

 Microchips used for identification purposes are generally implanted in the nuchal ligament in the neck. In a preliminary study, the research team found that temperature recorded by a PTSM chip implanted in the nuchal ligament correlated poorly with the CVT during and immediately after exercise. This was probably due to the poor vascular supply of the nuchal ligament compared to other muscles, they suggest.

 The researchers also found poor correlation between rectal temperature and CVT immediately after exercise and for at least 8 min after exercise. Because of this, and for safety reasons, they suggest that rectal temperature should not be used to measure temperature after exercise.

 Of the implantation sites they tested, they found that the most reliable was the pectoral muscles, which closely matched the CVT, followed by the gluteal muscles and the splenius muscle.

 They conclude that PTSMs provide a simple, safe, quick, accurate, and non-invasive way of measuring body temperature of horses immediately after high-speed exercise. They recommend further studies to validate this method under field conditions and in equine athletes working in extreme environments and intensive activity in various equestrian sports.

 

For more details, see:

 The Use of Percutaneous Thermal Sensing Microchips for Body Temperature Measurements in Horses Prior to, during and after Treadmill Exercise

Hyungsuk Kang, Rebeka R Zsoldos, Solomon M Woldeyohannes, John B Gaughan, Albert Sole Guitart 

Animals (Basel) (2020) ; 10(12):E2274.

doi: 10.3390/ani10122274