Horses in Asia Found Infected with H5N1 Avian Influenza

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A recent study has revealed that horses in Asia have been infected with H5N1 avian influenza,
with these infections occurring undetected.  

The research, led by Professor Pablo Murcia from the MRC-University of Glasgow Centre for Virus Research, in collaboration with an international team of scientists from the US and Mongolia, involved antibody testing on horse herds in Mongolia.  The findings, published in Emerging Infectious Diseases, reveal asymptomatic infections in Mongolian horse herds.

 

The researchers tested horse herds in two distinct Mongolian regions: a wetland area with a high population of wild birds and a dry area with low bird density. The results showed higher exposure rates in the wetland region. Importantly, there were no reports of previous respiratory disease outbreaks among the horses, suggesting that the infections were acquired asymptomatically.

 

These findings confirm that avian influenza can spread to other species, including horses. While equine influenza is typically caused by the H3N8 subtype, the detection of H5N1 highlights the potential for avian influenza to infect horses.

The study raises concerns about cross-species transmission, particularly in agricultural environments where horses may be exposed to infected livestock. Since March 2023, the rapid spread of H5N1 in US dairy cattle has amplified the risk of horses contracting avian influenza.

Coinfection with H5N1 and equine influenza (H3N8) could result in genetic reassortment, potentially creating new influenza strains with unpredictable consequences for animals and humans. Professor Murcia noted parallels to the 2009 swine-origin influenza pandemic, emphasizing the importance of preventing such reassortment events.

The researchers conclude by recommending serologic surveys in premises that keep horses. Such studies, they say, would aid early virus detection, provide a comprehensive picture of the changing ecology of avian influenza viruses, and inform the design of control measures to prevent influenza emergence.

This study highlights the need for:

1. Enhanced surveillance of influenza infections in horses, particularly in regions with high wild bird densities or significant interaction with infected livestock.
2. Strengthened biosecurity measures to reduce interspecies transmission in agricultural settings.
3. Further research into the mechanisms of avian influenza spillover and the potential for new virus emergence.

For more details, see: 

 

Batchuluun Damdinjav, Savitha Raveendran, Laura Mojsiejczuk, Ulaankhuu Ankhanbaatar, Jiayun Yang, Jean-Remy Sadeyen, Munir Iqbal, Daniel R. Perez, Daniela S. Rajao, Andrew Park, Mafalda Viana, and Pablo R. Murcia (2025)

Evidence of Influenza A(H5N1) Spillover Infections in Horses, Mongolia.

Emerging Infectious Diseases, 31(1) 

https://doi.org/10.3201/eid3101.241266 

https://www.gla.ac.uk/news/headline_1134067_en.html

Survey on SGLT2 Inhibitor Use in Horses with EMS or PPID

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Have you used an SGLT2 inhibitor (one of the          "-flozin" drugs) to treat your horse? If so, the Equine
Cushing's and Insulin Resistance Group (ECIR) invites you to contribute to an important research initiative.

Sodium-glucose cotransporter 2 inhibitors (SGLT2i), such as ertugliflozin and canagliflozin, are increasingly used to manage equine metabolic syndrome (EMS), particularly in horses with laminitis that has not responded to dietary changes. These drugs have shown potential benefits, including reducing serum insulin levels, aiding weight loss, and improving laminitis associated with hyperinsulinemia.

However, concerns have arisen about possible side effects, such as elevated serum triglycerides and liver enzyme levels, lethargy, and increased drinking and urination.

Dr. Kellon of the ECIR Group has created a survey to investigate factors that may influence the outcomes of SGLT2 inhibitor use in horses. This includes individual horse characteristics, comorbidities, and dietary factors that may contribute to or mitigate adverse effects.

If you are an owner, veterinarian, or caretaker of a horse receiving one of these drugs—such as canagliflozin, ertugliflozin, or dapagliflozin—you are encouraged to participate in the survey. Your insights will help enhance understanding and improve the management of metabolic disorders in horses and ponies.

The survey can be found here www.surveymonkey.com/r/YM5JD9G 

 

See also:

Eleanor M. Kellon, V.M.D. (Equine Nutritional Solutions) 

www.drkellon.com

 

Equine Cushing's and Insulin Resistance Group Inc.

www.ecirhorse.org

Green alternatives in equine reproduction

 The overreliance on plastic materials in all areas of modern life, including veterinary practice, poses a significant environmental challenge due to the pollution it generates.

Artificial insemination, a common technique in equine breeding programs, is a good example of the widespread nature of plastics in veterinary work. The procedure typically relies on disposable plastic items, such as insemination catheters and semen straws, which are essential for the collection, storage, and transfer of genetic material. However, their single-use nature contributes heavily to plastic waste. 

As part of the search for sustainable solutions, Noelia González and colleagues conducted a study to explore sustainable alternatives to conventional plastic semen straws. The study evaluated various biodegradable materials, including bamboo, avocado, grass, paper, Kraft paper, wheat, and rice, focusing on their suitability for preserving refrigerated, extended equine semen.

Among the materials tested, bamboo and avocado emerged as the most promising options. Bamboo displayed strong structural integrity, making it a durable and reliable container, However, avocado-based straws were particularly effective in maintaining sperm quality parameters, such as motility and movement kinetics, without introducing contaminants.

The research team conducted detailed assessments of the straws’ structural integrity and their ability to preserve semen quality after 24 and 96 hours of refrigeration. Both bamboo and avocado straws performed within acceptable ranges, but avocado straws yielded superior results. Additionally, microbiological control tests confirmed the absence of bacterial growth in both straw types, further supporting their potential as safe alternatives to plastic.

The findings suggest that avocado-based straws could serve as a viable alternative to plastic straws in artificial insemination procedures, offering an environmentally friendly solution without compromising the success of reproductive practices.

 

For more details, see:

 

González N, Peñalosa A, de Blas I, Gil L. 

Sustainable Alternatives to the Reduction of Plastic Straws Used with Chilled Equine Semen. 

Animals. (2024); 14(23):3388. 

https://doi.org/10.3390/ani14233388

Hand injuries more common during horse handling than riding

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Horse-associated hand injuries occur more frequently during horse handling than riding according to a new study.

 The most common injuries in equestrian sports involve the head, followed by injuries to the upper extremities and the thoracic and lumbar spine. Among hand injuries, riding a horse ranks third as a cause after ball sports and cycling.

A study conducted in Northern Germany by Benedikt Ritter and colleagues at the Department of Plastic, Aesthetic, Hand, and Reconstructive Surgery at Hannover Medical School examined the circumstances, mechanisms, and locations of horse-related hand injuries, as well as the use of protective equipment. The work is published in the Archives of Orthopaedic and Trauma Surgery

This retrospective cohort study analysed records of patients admitted to the hand trauma centre. Complete records, including follow-up data, were available for 39 patients over a five-year period. The cohort included 35 females and 4 males, with ages ranging from 9 to 65 years. Only 7.7% of participants were professional riders, while 92.3% were amateur riders, some with equestrian training qualifications.

Data from clinical records and telephone interviews were analysed to investigate the mechanisms of trauma and injury patterns.

Key Findings:

• Over half of the injuries (21 cases) occurred while leading the horse, primarily due to traction forces exerted by bridles or lead ropes on the fingers.
• Falls accounted for 13 cases, and 5 cases resulted from bite injuries.
• The phalanges (fingers) were the most injured site (33 cases), followed by the metacarpal bones (hand) (4 cases) and the carpal bones (wrist) (2 cases).
• Fractures were present in over half (20) of cases.
• avulsion amputations occurred in nine (23.1%) of patients 
• Thirty one cases (79.5%) required surgical intervention.

The researchers note that, while horse-related injuries represent a small proportion of total emergency visits, they are disproportionately severe. They say that this emphasises the need for targeted preventive measures and specialised care to address the high rate of serious outcomes associated with these injuries.

They recommend wearing appropriate protective gloves to prevent hand injuries, as well as using self-opening panic hooks with overload protection to prevent excessive traction.

 

For more details, see: 

 

Ritter, B., Dastagir, N., Tamulevicius, M Bucher F, Obed D, Vogt PD, Dastagir K.

Equestrian-associated injuries of the hand: a retrospective analysis of injury mechanisms and patterns. 

Arch Orthop Trauma Surg (2024) 144, 4937–4945

https://doi.org/10.1007/s00402-024-05586-x

New tool to aid worm control

  

A free online tool to help horse owners evaluate the risk of worm infection has been launched. 

 

This simple, user-friendly resource, titled ‘What’s Your Worm Risk?’, has been developed by Austin Davis Biologics in collaboration with equine industry.

 

Anthelmintic resistance poses a significant threat to equine health and welfare, with cases now reported in all common horse worms. Effective worm control begins with assessing a horse’s risk of infection, providing essential information for decisions regarding management, testing, and treatment.

 

The tool uses widely accepted principles of equine worm control to classify each horse's risk of infection as low, moderate, or high, based on details provided by the owner. It also accounts for the potential impact of grazing companions, where applicable.

 

Jacqui Matthews, a specialist in parasitology and director of veterinary science at Austin Davis Biologics, explains: “The tool is designed to support horse owners in assessing their horse’s risk of infection, helping them make informed decisions about testing and treatment.”

 

To reduce the risk of wormer resistance, experts recommend combining excellent pasture management—reducing worm transmission from paddocks—with regular testing to guide treatment decisions.

• Faecal worm egg count (FEC) tests provide an insight into worm egg shedding levels in manure.
• Antibody tests reveal the horse’s exposure to worm infections.

 

This approach minimizes the need for blanket wormer treatments, which are known to promote resistance and reduce the effectiveness of essential drugs.

 

The ‘What’s Your Worm Risk?’ tool has been optimised for use on smartphones, laptops, and desktop computers and is tailored specifically to UK conditions.

 

By integrating testing and evidence-based treatments into worm control plans, horse owners can protect their animals while reducing the risk of drug resistance in the equine population.

 

For more details, see: 

 

https://www.whatsyourwormrisk.com

New reporting initiative for clinical redworm disease in the UK

 Equine Infectious Disease Surveillance (EIDS) has launched RedWatch, a new initiative designed for vets to report cases of redworm disease in horses.

 

Based at Cambridge University, EIDS collects and analyses national disease data from diagnostic laboratories and veterinary practices across the UK. Their work provides valuable insights into the prevalence of equine infectious diseases. In addition to operating various surveillance programs, EIDS offers disease control advice and shares critical disease information through platforms like the International Collating Centre (ICC), EquiFluNet, and the Equine Quarterly Disease Surveillance Report, a collaborative effort with BEVA, Defra, and APHA.

 

Historically, large redworm infections—most notably caused by Strongylus vulgaris—have been significantly reduced in the UK due to the widespread use of anthelmintics. However, the overuse of these treatments has led to growing resistance, especially in small redworms (cyathostomes). As a result, there has been a shift towards reducing anthelmintic use and focusing on management-based strategies to control parasitic diseases.

 

Concerns remain, however, that reduced anthelmintic use could unintentionally alter the patterns of parasite-associated diseases. To address this, EIDS has introduced RedWatch, a targeted surveillance initiative.

 

RedWatch will collect and disseminate case data on diseases caused by small and large strongyles, including cyathostominosis and Strongylus vulgaris. Veterinary surgeons are encouraged to submit information via an online form, recording:

·       Vet and practice details

·       Case-specific information

·       Diagnostic methods

·       Clinical signs observed

·       Data about the premises and equine population

·       Potential risk factors

All submitted data will be securely stored and anonymised for public reporting. This will support education, awareness, and ongoing research into equine parasitology.

 

Large strongyles are often only detected during post-mortem examinations (PME) and are likely to be captured mainly through the Equine Quarterly Disease Surveillance report’s post-mortem surveillance section.  However, RedWatch will allow veterinary surgeons to report large strongyle cases that have not undergone an official PME.

 

"RedWatch is an exciting step in equine parasitology surveillance," said Fleur Whitlock, veterinary surgeon and epidemiologist at EIDS. "This initiative relies on veterinary surgeons sharing data and their engagement is key to filling knowledge gaps. By contributing case reports, vets can directly support efforts to prevent these devastating diseases and help pave the way for new tools like real-time reporting and risk warnings.”

 

EIDS is generously funded by the UK’s Thoroughbred industry and is based at Cambridge University.

 

For more details, download the latest Equine Quarterly Disease Surveillance report

https://equinesurveillance.org/landing/resources/reports/dsr20243.pdf

 

Veterinary surgeons can record cases at

www.equinesurveillance.org/redwatch