ASK THE EXPERT.
FIGHTING FLU WITH SCIENCE EQUINE INFLUENZA CAN HAVE A SERIOUS IMPACT ON HORSE HEALTH, AND AN OUTBREAK CAN CAUSE DISRUPTION TO COMPETITION PLANS AS WE HAVE SEEN IN RECENT YEARS. DR ESTHER RAWLINSON MRCVS TALKS ABOUT WHY THIS DISEASE IS SUCH A CAUSE FOR CONCERN AND HOW TO TACKLE IT WITH IMPROVED BIOSECURITY AND VACCINATION.
Q
What is equine influenza? E uine in uen a u is a viral respiratory infection whose signs include a high temperature, cough, nasal discharge, depression and loss of appetite. econdary bacterial infections are common and prolong the disease, re uiring further treatment. s well as affecting performance, in rare cases u can cause serious complications and even death. he effects can be more severe in foals, elderly horses and those suffering from other health problems. ecuperation from the disease can take several weeks and often re uires the whole yard to go into isolation. lu spreads very rapidly between horses when an infected horse coughs or snee es, the virus can spread through the air up to several kilometres1. It can also be transmitted on ob ects such as tack, feed bowls, water troughs or clothes, so horses are at risk even if an infected horse is no longer present.
Q
Why do flu outbreaks occur? lu is endemic in the which means it is always circulating in our horse population. he more horses are vaccinated against u, the less the chance of a serious outbreak occurring, however only about of horses in the are vaccinated, leaving a large
40 // Issue 3 2022 // BRITISH DRESSAGE
vulnerable population which increases the risk of a ma or u outbreak, as happened in . Biosecurity is also important to reduce the risk of outbreaks. horse can be shedding virus and infecting others before showing any signs of ill health so we should minimise contact with horses from other yards, for e ample at competitions avoiding nose to nose contact, sharing of e uipment, or gra ing communal areas. ew arrivals to a yard should be uarantined, especially if they are unvaccinated this was a common source of spread in the outbreak. t all times good stable ventilation is of paramount importance.
Q
How do vaccines work? imilar to ovid vaccination in people, u vaccination does not prevent horses getting infected, but the aim is to protect the vaccinated horse from becoming seriously ill, and to reduce the amount of virus it sheds, which reduces the risk of infecting other horses. accination stimulates the immune system so that it is primed to recognise the u virus and ready to uickly protect the horse if it becomes infected in the future. o comply with British ressage rules as shown in the handbook an initial course
of two in ections for primary vaccination, not less than days and not more than days apart, is re uired before being eligible to compete. Immunity declines over time so regular boosters are needed to “remind the immune system. Boosters don’t ust protect the individual horse, they also reduce the risk of spreading infection to others. ompetition governing bodies continually review the risk of an outbreak and may change vaccination re uirements depending on current risk levels. British ressage re uires that the fi rst booster in ection must be given between and days after the second in ection of primary vaccination. ubse uent booster in ections must be given at regular intervals of not more than months, commencing after the fi rst booster in ection.
