Equine Herpesvirus (EHV) UK 2025: Symptoms, Vaccination & Care

Whether you are finding a horse for sale or caring for one in the UK, understanding Equine Herpesvirus (EHV) in 2025 is vital for safeguarding your horse’s health and welfare. This comprehensive guide covers EHV strains, symptom recognition, vaccination schedules, outbreak management, biosecurity protocols, and legal considerations based on the latest UK veterinary advice.

Understanding Equine Herpesvirus and UK Strains in 2025

Equine Herpesvirus (EHV), mainly types EHV-1 and EHV-4, is a contagious viral infection widespread among UK horses in 2025. Both strains can establish latent infections that reactivate under stress such as transport or illness, making control challenging.

• EHV-1: Causes respiratory illness, late-term abortions in pregnant mares, and Equine Herpesvirus Myeloencephalopathy (EHM), a severe neurological disease characterised by hindlimb weakness and paralysis.
• EHV-4: Primarily induces respiratory issues, especially in young or stabled horses, with rare abortion or neurological complications.
• Other strains: EHV-3 causes venereal disease, while EHV-5 is linked to rare lung conditions but is less common.

Recognising these strains facilitates early veterinary intervention, limits virus transmission, and safeguards the wider equine community.

Recognising Equine Herpesvirus Symptoms

Symptoms vary by strain; early detection is essential for effective treatment and outbreak control.

Respiratory Signs (EHV-4 and Some EHV-1)

• Fever above 38.5°C lasting multiple days
• Clear to thick nasal discharge, sometimes purulent due to secondary infection
• Persistent dry or productive cough
• Swollen lymph nodes under the jaw
• Lethargy and reduced appetite
• Lower exercise tolerance
• Occasional mild conjunctivitis or limb swelling

Neurological Signs (Primarily EHV-1)

• Hindlimb weakness and incoordination (ataxia)
• Staggering gait and reluctance to move
• Loss of tail tone and urinary or faecal incontinence possible
• Head tilt or partial paralysis
• Rapid deterioration requiring emergency veterinary care

Pregnant mares may experience sudden abortions without prior symptoms. Immediate isolation and veterinary consultation are crucial to protect both the mare and the herd.

How Equine Herpesvirus Spreads and Essential Biosecurity Measures

EHV spreads through respiratory droplets, direct contact between horses, and indirectly via contaminated equipment or environments, with the virus surviving on surfaces for up to a month without appropriate cleaning.

• Quarantine new or returning horses for 14 to 21 days before integrating them with the stable herd.
• Employ dedicated or disposable tack and grooming equipment to prevent cross-contamination.
• Disinfect stables, transport vehicles, and grooming tools daily using veterinary-approved virucidal cleaners.
• Handlers should maintain strict hand hygiene and wear disposable gloves when handling suspected or confirmed cases.
• Avoid stressors such as transportation or mixing unfamiliar groups to prevent viral reactivation.

2025 UK Vaccination Guidelines for Equine Herpesvirus

Vaccination is a key strategy to reduce respiratory illness and abortion risks from EHV-1 and EHV-4; however, it provides limited protection against neurological disease (EHM). Vaccination schedules should be tailored based on the horse’s risk, lifestyle, and veterinary advice.

• Foals: Typically receive a primary 3-dose series starting at 4 to 6 months of age, with 4 to 6 weeks between initial doses, and a third dose at 10 to 12 months, followed by boosters every six months to maintain immunity.
• Pregnant mares: Vaccinated at months 5, 7, and 9 of gestation to reduce abortion risk.
• High-risk or frequently travelled horses: May require more frequent boosters per veterinary guidance.

Avoid vaccination during active outbreaks to prevent post-vaccination fevers that may complicate clinical diagnosis. These recommendations align with Liphook Equine Hospital and current UK veterinary consensus.

Step-by-Step Outbreak Management in UK Stables

Step 1: Immediate Isolation

Rapidly isolate symptomatic or confirmed EHV-infected horses and restrict movements of horses, staff, and equipment on the premises for at least 21 to 28 days following the last confirmed case or abortion to curb virus spread.

Step 2: Rigorous Hygiene and Dedicated Care

Assign dedicated staff for infected horses, equipped with gloves, gowns, and boots. Thoroughly disinfect stables, tack, bedding, and transport vehicles. Safely dispose of contaminated materials to reduce risk.

Step 3: Quarantine New Arrivals

New or returning horses must undergo 14 to 21 days quarantine under veterinary supervision, with close monitoring for clinical signs before being introduced to the yard.

Step 4: Diagnostic Testing

Use PCR or LAMP testing on nasal swabs and blood samples to confirm infection and identify carriers, guiding outbreak control strategies.

Step 5: Communication and Movement Control

Notify veterinarians, yard owners, local equestrian community, and relevant authorities immediately after diagnosis. Maintain movement restrictions until all horses have recovered and test negative.

Step 6: Veterinary Support and Treatment

Supportive care includes fluid therapy, anti-inflammatory medications, rest in a low-dust environment, and antivirals such as valaciclovir as advised by your vet. Vaccination combined with strong biosecurity remains vital.

Legal Status and Reporting in 2025 UK

Equine Herpesvirus is not legally notifiable in the UK; mandatory government reporting or movement bans are not enforced. Voluntary reporting to the Horseracing Betting Levy Board (HBLB) and British Equine Veterinary Association (BEVA) supports national disease monitoring.

Licensed training yards must report cases to the British Horseracing Authority (BHA), which may impose movement restrictions under industry biosecurity rules. The 2025 HBLB guidelines emphasise responsible outbreak management through timely reporting and stringent hygiene practices.

Common Mistakes in Managing Equine Herpesvirus in UK Horses

• Vaccinating horses already exposed or during active outbreaks, which can worsen immune responses and delay diagnosis.
• Delayed or inadequate quarantine, failing to promptly isolate new arrivals and symptomatic horses.
• Poor biosecurity, including lack of dedicated equipment and handlers, insufficient disinfection, and poor personal hygiene.
• Insufficient monitoring, such as not recording temperatures twice daily or delayed veterinary notification.
• Failing to isolate virus-shedding horses for the required 21 to 28 days or omitting repeat PCR testing to confirm clearance.
• Overreliance on vaccination without enforcing quarantine and biosecurity, despite vaccines reducing severity but not fully preventing neurological disease.
• Misunderstanding vaccination protocols, booster timing errors, or vaccinating during outbreaks without veterinary guidance.
• Neglecting management of latent carrier horses and immune support to reduce reactivation risk.

Effective control requires vaccination as part of a comprehensive strategy prioritising quarantine, hygiene, stress reduction, and veterinary collaboration.

Responsible Management: Protecting Your Horses and Equine Community

Equine Herpesvirus remains a serious threat to horse health. Responsible care combining vaccination, robust biosecurity, prompt symptom recognition, isolation, continuous monitoring, and clear communication protects your horse and the wider equine community.

Following UK 2025 guidelines equips owners and yard managers to manage EHV outbreaks effectively, improving animal welfare and limiting virus transmission.