8 February 2019: At the current time owners are advised not to import horses to the Isle of Man unless necessary and we would ask for the co-operation of horse owners with this. If horses are to be imported increased biosecurity will be required to help protect the Isle of Man horse population.
Import licenses now contain an additional requirement to isolate horses for two weeks following importation. This covers the incubation period and will enable detection of the disease should it occur and further isolation to contain the disease.
Horses must be kept isolated for 14 days following importation.
Equine influenza is a highly infectious disease of horses, mules and donkeys occurring globally caused by strains of Influenza A virus. It is the most potentially damaging of the respiratory viruses that occur in UK equines and disease symptoms in non–immune animals include high fever, coughing and nasal discharge.
The recent outbreak in Britain follows the identification of a number of equine influenza cases across Europe and the UK, including several in vaccinated horses.
Equine Influenza can be highly contagious and – unlike other infectious diseases – can be airborne over reasonable distances as well as be transmitted indirectly, including via people. There are no known consequences for humans associated with exposure to the disease.
In unvaccinated horses we tend to see certain ‘cardinal’ signs. The virus targets the upper respiratory tract where the cough receptors are positioned so a very harsh dry cough is typical. Often horses will develop a raised temperature which will last around 7-10 days, during this time they may be quiet, off their food and generally sluggish, they may also have a small amount of clear or white nasal discharge and enlarged lymph nodes in their throat.
Horses that have been regularly vaccinated often show no clinical signs, but they may still shed enough virus to infect other horses. This is how the outbreak in Australia in 2007 started.
Horses that have been vaccinated but only have partial protection, e.g. because they haven’t been vaccinated frequently enough or because the vaccine type used was not updated, may show varied signs of mild non-specific respiratory disease. This can include mild lethargy, nasal discharge and possibly a cough.
The Animal Health Trust are the equine monitoring agent for disease surveillance in the UK and information is posted on their website and twitter feeds.
For further information and advice, please contact your private veterinary surgeon.