Influenza outbreak (February 2019)

These information sheets are provided for your interest. They should not replace veterinary advice from your veterinary surgeon.

Whilst every effort is taken to ensure the accuracy and completeness of the information provided, your specific circumstances must be discussed before advice can be given.

We will keep this page updated with our latest advice on protecting your horses from the current outbreak of equine influenza.

Updated case information can be found on the @equiflunet twitter feed. This is provided by the Animal Health Trust.


The influenza virus isolated from the confirmed cases so far have been of type FC1 (Florida clade 1). None of the commercially available vaccines contains this exact strain, but this is not unusual - the strains included are chosen as representatives which will give cross-protection against as many types as possible. In this outbreak, cases have been seen in vaccinated horses, which is why it is being treated very seriously. Our current understanding is that there is cross protection against FC1 by the currently available vaccines, provided the antibody level is high enough. This is why we are recommending an extra booster vaccine for any horse which has not had a booster within the last 6 months.


Foals born in the next few months will be protected by maternal antibody so long as the mare is recently vaccinated, and there is good colostral antibody transfer. If there is any doubt, or if the infection risk remains high, an extra starter dose can be given from 4 months of age, followed by the normal 2 dose starter course from 6 months.