Veterinary experts have issued a timely reminder to horse owners to ensure their animals are vaccinated against equine flu after a raft of new outbreaks have been recorded in the UK over the last three months.
“Since mid-August there have been 28 reported outbreaks of equine flu throughout the UK,” says Nicola Snowden BVM&S MRCVS, equine veterinary advisor for the Keeping Britain’s Horses Healthy campaign.
Equine flu is a highly contagious disease, yet adopting preventative healthcare practices such as vaccination can reduce the impact on both individual horses and the wider equine industry.
What are the symptoms?
Equine flu is a highly contagious infectious viral disease that can cause acute respiratory disease in naïve horses with symptoms including high fever, coughing and nasal discharge. Depression, reduced or absent appetite, and weakness are also frequently observed.
Most adult horses recover from the initial episode within a few weeks, however the time taken to regain full health and to resume normal activities may be many months and performance may be impaired. In foals and immunocompromised horses the outcome can be fatal.
Where are the outbreaks?
The outbreaks recorded by the Animal Health Trust in 2014 are extremely widespread as follows:
• 15 August – West Lothian
• 19 August – Bedfordshire
• 11 September – Sussex
• 15 September – Cornwall
• 23 September – East Lothian
• 25 September – Perthshire
• 25 September – Essex
• 25 September – Somerset
• 29 September – West Sussex
• 30 September – Staffordshire
• 8 October – Ayrshire
• 10 October – Scottish Borders
• 21 October – Warwickshire
• 23 October – Ayrshire
• 27 October – Cumbria
• 27 October – Perthshire
• 27 October – Worcestershire
• 31 October – Worcestershire
• 31 October – West Midlands
• 31 October – Kent
• 31 October – Scottish Borders
• 4 November – Cambridgeshire
• 7 November – Kent
• 7 November – Buckinghamshire
• 12 November – Leicestershire
• 26 November – Yorkshire
• 27 November – Gloucestershire
• 26 November – Staffordshire
How does it spread?
Flu is an airborne virus and can rapidly spread through a yard or even to neighbouring yards under the right prevailing weather conditions, particularly where there are susceptible unvaccinated horses. As such, these 28 outbreaks may quickly spread locally and to other regions, particularly if there are large numbers of unvaccinated horses.
How is it prevented?
“Vaccination is key in the prevention of infectious and contagious diseases such as flu,’ says Nicola.
“Not only are unvaccinated horses at risk of ill health themselves should they become infected, but they also pose a risk to other horses as they shed large amounts of the contagious virus. Although vaccination does not provide complete protection against disease, the clinical signs and level of virus shedding after infection is significantly less.
"For vaccination to be most effective and to control infectious and contagious disease, consideration needs to be given not only to the individual horse but also to the immunity of the equine herd.”
Herd immunity describes the situation when a sufficient proportion of a population – though not necessarily all – are vaccinated against a disease. If there are too few susceptible horses in a population, the disease is unable to spread. The minority of horses who aren’t vaccinated will receive protection because the spread of the disease is contained by the large majority that are.
Essentially, the principle can be described as safety in numbers.
Information drawn from the number of flu vaccinations sold to vets in the UK last year indicates that less than half of the UK’s one million or so equine population is vaccinated. This is not enough to establish herd immunity and therefore leaves our UK population of horses at risk from flu.
Vaccinating regularly is the best way to protect your horse against disease caused by influenza. Vaccination in large enough numbers can also protect the herd, whether this is your horse’s field companion or the other horses on your yard.
Vaccinating a large proportion of the equine population will limit the ability of the virus to spread so reduce the incidence of outbreaks.
To minimise the risk to your horse and to prevent the spread of equine flu in your area, ensure your own horse is up to date with their vaccinations and encourage owners of horses surrounding yours to ensure their horses are also vaccinated against equine flu.