Keeping bugs at bay

Recent outbreaks of disease have highlighted the need for tight biosecurity. Kieran O’Brien MRCVS outlines the measures that provide the required protection

-  Kieran O’Brien

THE 2019 equine influenza epidemic in the UK, in which the disease was confirmed in 234 individual premises – in contrast to only two in 2018 – reminded us that infectious diseases are an ever-present risk to the UK horse population. Horses are constantly being moved around the country and arriving from overseas.

An analysis of the 2019 outbreak concluded that the spread of influenza was aided both by no or insufficient vaccinations, and poor biosecurity practices on many of the premises. In around half of the outbreaks, a new horse had arrived on the premises in the previous two weeks.

These findings confirm that in the UK when it comes to biosecurity, we have a big hill to climb. All horses are at risk of encountering infectious pathogens either directly or indirectly during their lives, especially those horses that are kept in yards that are not “closed” (those with no horse movements on or off the premises).

The aim of biosecurity is to prevent infections – principally respiratory, enteric (affecting the intestines) and those affecting the skin – from entering yards by ensuring satisfactory pre-screening, vaccination and quarantine.

When infections do arrive, biosecurity aims to limit spread by isolating the affected horse or horses, and by preventing indirect spread via personnel, feeding and watering utensils, tack and grooming tools. In “open” yards the horses travelling to competitions, or off the premises for any other reason, should ideally be kept in a separate part of the yard, with no contact with those that do not travel from the yard.

The important infectious diseases in the UK are influenza, equine herpes virus (EHV), strangles and the fungal skin infection ringworm.