b' In addition to vaccination logs andbarrier, so its easier for people to comply a current negative Coggins (equinewith separation protocol, with separate infectious anemia test), many facilitiessupplies, clothing, and footwear. require owners to show a veterinarian- Color-coding supplies and clothing issued health certificate dated seven tomight also help with compliance.30 days prior, depending on the event.In 2017 German researchers found that However, some facilities still have nothe EHV-1 virus could persist for up to health certificate requirements. three weeks in water under optimal pHFEI competitions include microchip- and temperature conditions. ping and horse passport requirements;While this is not an outbreak finding, separate and secure stabling, grazing,it would potentially tell us that we should and schooling areas; and on-site veteri- be concerned about the use of shared nary inspections. water sources, says Traub-Dargatz. ThisThe USEF now requires competitionincludes buckets, troughs, and hoses management to file an isolation proto- transferring from bucket to bucket. col. This includes a plan for quarantine stabling, obtaining supplies, and treat- Take-Home Messagement and handling protocols, as well asWhile EHV-1 has been around for a plan to be used for horses that mightyears, it hasnt always been considered a have been in contact with an ill horse. disease of regulatory importance. With COURTESY DR. KATIE FLYNNThe USEFs isolation plan require- the increasing number of incidents, the ment for sanctioned events is a first stepequine industry and state regulatory offi-for a more comprehensive biosecuritycials became aware of the impact of such plan involving entry requirements, earlya disease, says Flynn. The economic detection of disease, and early actionimpact of an outbreak can be substantial. plan for response if disease occurs, saysRegulatory bodies such as the USEF now en- Aside from the direct cost due to horse Traub-Dargatz. force quarantine protocols for affected horses. fatalities, there are many other costs as-However, Flynn notes, many facilitiessociated with treatment, quarantine, can-cannot fulfill isolation protocols. Un- from exposed horses beyond the previ- celed events, and the inability for horses fortunately, most equine facilities haveously proposed two-to-10-day sheddingto perform and compete in equestrian limited isolation stabling available,period. During recent incidents, saysevents.she says. On-site and off-site stablingFlynn, the laboratory detected EHV-1 inWith improved communication be-availability is a challenge during the busyhorses 21-28 days post-initial infection.tween agencies, incident documentation, show or fair season when temporaryAdditionally, detections in severaland access to outbreak data, the veteri-stabling is not available. Lack of isolationhorses were at a very low level, shenary community continues to learn more or inappropriate isolation stabling forsays, which poses the question, is theabout the disease.test-positive equids poses a real challengepolymerase chain reaction (PCR) test de- This field experience and knowledge is to regulatory officials, as an inability totecting traces of residual nucleic acid oressential for advancing equine regulatory isolate the index case(s) often leads toinactive virus (basically, viral DNA)? AreEHV-1 responses, says Flynn. Equine prolonged quarantines due to continuedthese horses with a very low level of virusherpesvirus myeloencephalopathy was disease spread. capable of infecting another horse? added to Californias reportable disease Outbreak data and more advanced andUntil researchers can determine trans- list in 2011. Since that time we have rapidly available diagnostic test capabili- mission risk for low-shedding horses, reg- investigated over 25 incidents of EHM (in ties indicate horses might be contagiousulatory officials will continue to requirethe state). These incidents have provided longer than previously thought.two negative tests for quarantine releasenew insights into a virus that has been Historically, research has indicatedand recommend handling these horses asaround for many years.that infected horses shed virus at onset ofpotentially infectious, says Flynn.We have to accept we dont currently fever, says Flynn. However, during ourCreating a safe distance betweenhave the means or method to avoid the outbreaks (here in California), several fe- horses needs to happen both at eventsindex EHM case in all situations, so brile horses tested negative on initial na- and at home when horses are coming andcontrol really revolves around our detec-sal swab samples and positive on samplesgoing. Avoid direct nose-to-nose contacttion and response to that first case, says submitted 72 hours later. Recommendedwith horses that arent part of your herd,Traub-Dargatz. We have come a long regulatory response protocols have beenand keep new introductions separate forway with our communication, informa-revised and recommend resampling sus- two to three weeks while monitoring fortion resources, and biosecurity. Its not pect exposed horses 48-72 hours later tosigns of disease, says Traub-Dargatz.easy, but more and more owners, veteri-determine EHV-1 status. By keeping isolated horses in a totallynary practitioners, and the industry in Current diagnostic testing technologyseparate area, you not only avoid sharinggeneral are embracing those concepts. We has also detected virus in nasal swabsair space but also create a functionalhave things to be optimistic about. hTheHorse.com | The HorseAugust 201931'