Sunday, March 28, 2021

Genetic risk of fracture in Thoroughbreds

Scientists at the Royal Veterinary College (RVC) have received funding for a study into the genetic risk of fractures in Thoroughbred racehorses.

The research paves the way for greater understanding of how best to identify and manage horses at high risk of such fractures and contribute to greater health and welfare of Thoroughbreds.

It is possible to monitor horses using diagnostic imaging techniques (such as radiography and CT scan) to identify changes in bones that could lead to fractures. However, such techniques are too expensive for routine use. This new research could potentially allow veterinary professionals to identify genetically high-risk horses and enable a more targeted – and therefore less expensive – use of these methods.

The research team at the RVC have used genome wide information to derive types of stem cells known as ‘induced pluripotent stem cells’ (iPSCs) from horses at high and low genetic risk of fracture. These iPSCs can then be turned into osteoblasts, the cells that produce bone. This innovative method allows researchers to study bone from high and low risk horses in the absence of any environmental variability, thus giving them the chance to look closely at the purely genetic factors that underpin fracture risk in Thoroughbreds.

Furthermore, identifying the mechanisms which underpin genetic risk in horses will allow future research to develop novel therapies and interventions for high-risk horses to decrease their risk of catastrophic facture. Identifying horses at high genetic risk would also allow breeders to make informed breeding decisions to reduce the probability of breeding horses at high genetic risk of fracture. This project therefore has the potential to significantly improve the health and welfare of racing Thoroughbreds.

The research has been made possible by a grant awarded by the Alborada Trust, an organisation that supports medical and veterinary causes, research and education and the relief of poverty and of human and animal suffering, sickness and ill-health. 

Lead researcher, Dr Debbie Guest, Senior Research Fellow at the RVC, said “I am delighted to have received funding from the Alborada Trust for this project. Bone fractures are a common problem in racing Thoroughbreds and this work has the potential to make a significant improvement to Thoroughbred health and welfare.”

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)

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:

Saturday, March 27, 2021

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

Sunday, March 21, 2021

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:

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:

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:

Saturday, March 20, 2021

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: