Equine Veterinary Journal has placed equine infectious disease and microbiology centre stage in its March 2026 issue, bringing together 30 papers in a comprehensive Special Focus that is free to view for 12 weeks.
Edited by Julia Kydd and Celia Marr, with guest editors Macarena Sanz, Tessa LeCuyer and Laura Peachey, the collection reflects the continued global research effort dedicated to understanding and controlling infectious disease in horses. Many of the manuscripts involve international collaboration and span a wide range of disciplines, pathogens and body systems.
Three key themes
The Special Focus addresses three overarching themes:
- The value of national level disease surveillance programmes
- The importance of obtaining a definitive diagnosis
- The use of cross-species comparisons to better understand pathogens affecting multiple animal species
Across the issue, the emphasis is clear, improving detection, refining diagnosis and strengthening prevention strategies.
Advances in diagnostics and surveillance
Several studies report advances in diagnostic techniques for equine fever, equine influenza and equine gastrointestinal parasites, developments that could accelerate the implementation of biosecurity measures and limit disease transmission.
From a surveillance perspective, a report on equine herpesvirus myeloencephalopathy concludes that sampling the air space within stables for EHV-1 DNA may offer a useful, non-invasive monitoring tool. Another study highlights overlap between racehorse and sport horse populations, identifying concentrated windows for local or indirect pathogen spread, such as aerosolised respiratory transmission, and noting that inconsistent horse identification across non-racing disciplines remains a barrier to effective disease preparedness.
Gastrointestinal, respiratory and multisystem disease
A series of gastrointestinal studies expand knowledge of proliferative disease in foals through metabolic profiling, explore the potential aetiology of colitis, and underline the need for additional testing for chronic hepatitis and liver failure in cases involving hepacivirus.
Seven respiratory-focused papers include work on strangles, emphasising that effective prevention requires investment in screening, consistent quarantine practices, close monitoring and interconnected reporting. As novel vaccines emerge, the equine community may become better equipped to reduce the impact of this important disease.
Research into endemic Rhodococcus equi pneumonia in foals provides detailed characterisation of immune and hormonal changes from birth to weaning, although none of the measured parameters reliably predicted future respiratory disease. In equine influenza, a study investigating vaccination against type A virus demonstrates the promise of a combined adjuvant approach to optimise immune responses to commercially available vaccines.
Antimicrobial resistance and treatment protocols
Two papers tackle the growing challenge of antimicrobial resistance. A survey found that almost 40% of hospitalised horses received at least one antimicrobial. In colic surgery cases, antimicrobial prophylaxis beyond 24 hours was shown to be unnecessary to prevent post-surgical complications, reinforcing the need for evidence-based prescribing.
Regional and emerging diseases
The issue also examines regionally significant and emerging diseases. Research into Hendra virus analyses horse population datasets and field surveys to model the emergence of zoonotic pathogens. Another study demonstrates that horses infected with African Horse Sickness Virus develop severe consumptive coagulopathy, clinically manifesting as a bleeding phenotype. Importantly, infection with equine encephalosis virus is highlighted as a key differential diagnosis for African Horse Sickness in endemic regions.
Two systematic reviews focus on equine trypanosomiasis, providing guidance for more robust disease control strategies. A separate paper reports on a novel diagnostic tool for differential detection of T. haneyi, a main cause of equine piroplasmosis, and provides the first evidence of T. haneyi in China.
Reproductive and integumentary findings
In the reproductive sphere, one study shows that isolation of E. coli, but not other bacteria, is associated with decreased fertility in Thoroughbred broodmares. Another applies in vivo multi-omics to nocardioform placentitis and proposes renaming it mucoid placentitis due to the broad range of bacteria identified.
A rare case of progressive necrotising skin ulceration highlights the importance of definitive diagnosis in non-resolving infectious processes and the value of comparing similar infectious agents across species, particularly where equine-specific data are limited.
The equine microbiome, seven years on
Alongside the infectious disease focus, the issue includes a Special Collection on the equine microbiome, updating EVJ’s 2019 collection and showcasing the significant progress made in understanding the microbiome’s complexity and its practical applications in horses over the past seven years.
Julia Kydd commented:
“The considerable and diverse research efforts within this Special Focus will ultimately improve the detection, diagnosis, treatment and control of many pathogens. The eventual aim is to prevent or minimise the impact of future outbreaks. This will help the equine industry internationally but very importantly improve equine welfare and the quality of life for those people who rely on working equids for their daily survival.”
The March 2026 Special Focus issue of Equine Veterinary Journal is available to view free for 12 weeks via the journal’s website. Click here for the link to view.
