{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,30]],"date-time":"2026-10-30T03:33:49Z","timestamp":1793331229676,"version":"4.5.0"},"reference-count":15,"publisher":"American Veterinary Medical Association (AVMA)","license":[{"start":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T00:00:00Z","timestamp":1783641600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["javma"],"published-print":{"date-parts":[[2026,7,10]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>Describe the effects and outcomes of valacyclovir and heparin administration in equine herpesvirus-1 (EHV-1)\u2013exposed horses.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A multicenter retrospective study identified 111 horses naturally exposed to EHV-1 from August 2017 to March 2018. Equine herpesvirus-1 infection was confirmed via blood or nasal secretion PCR. Horses that developed neurologic signs were diagnosed with equine herpesvirus myeloencephalopathy (EHM). Clinical signs, treatment, and survival were reported. A subset of horses was treated with valacyclovir and heparin. Prophylactic medication administration was performed prior to development of EHV-1 clinical signs (temperature &gt; 38.6 \u00b0C, limb edema, nasal discharge, or neurologic deficits). Medication administration to clinical cases was defined as metaphylactic. Survival and EHM incidence were assessed between horses that received valacyclovir and heparin and horses that did not.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>22 horses were diagnosed with EHV-1, with 9 developing EHM. Fourteen EHV-1\u2013positive horses received metaphylactic valacyclovir and heparin, with 5 developing EHM. Five EHV-1\u2013positive horses received prophylactic valacyclovir and metaphylactic heparin, with 1 developing EHM. Four EHV-1 horses were not treated with valacyclovir or heparin; all developed grade 5\/5 ataxia and were euthanized. All horses treated with valacyclovir and heparin survived.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>EHV-1 treatment with valacyclovir and heparin reduced the incidence of EHM and improved survival compared to horses that did not receive these medications.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Clinical Relevance<\/jats:title>\n                    <jats:p>In confirmed EHV-1 outbreaks, the administration of valacyclovir prior to the development of EHV-1 clinical signs and the administration of heparin after the development of clinical signs may improve patient survival.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.2460\/javma.26.02.0118","type":"journal-article","created":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T16:48:59Z","timestamp":1783702139000},"page":"1-6","source":"Crossref","is-referenced-by-count":1,"title":["Combined treatment with valacyclovir and heparin reduced the incidence of equine herpesvirus myeloencephalopathy and improved survival in naturally occurring equine herpesvirus-1 outbreaks"],"prefix":"10.2460","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-0605-7484","authenticated-orcid":true,"given":"Megan","family":"Marchitello","sequence":"first","affiliation":[{"name":"Marion duPont Scott Equine Medical Center, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Leesburg, VA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9321-1952","authenticated-orcid":true,"given":"Krista","family":"Estell","sequence":"additional","affiliation":[{"name":"Marion duPont Scott Equine Medical Center, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Leesburg, VA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0138-8118","authenticated-orcid":true,"given":"Elsa K.","family":"Ludwig","sequence":"additional","affiliation":[{"name":"Marion duPont Scott Equine Medical Center, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Leesburg, VA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abby M.","family":"Sage","sequence":"additional","affiliation":[{"name":"Zoetis\u2014Global Animal Health Co, Parsippany, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7845-3788","authenticated-orcid":true,"given":"Nathaniel A.","family":"White","sequence":"additional","affiliation":[{"name":"Marion duPont Scott Equine Medical Center, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Leesburg, VA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1272","reference":[{"issue":"3","key":"ref1","series-title":"J Vet Intern Med","first-page":"450","article-title":"Equine herpesvirus-1 consensus statement","volume":"23","author":"Lunn DP","year":"2009","unstructured":"Lunn DP, Davis-Poynter N, Flaminio MJ,  Equine herpesvirus-1 consensus statement. J Vet Intern Med. 2009;23(3):450-461. doi:10.1111\/j.1939-1676.2009.0304.x"},{"key":"ref2","series-title":"Proceedings of the 52nd Annual Convention of the American Association of Equine Practitioners","first-page":"223","article-title":"Detection of nasal shedding of EHV-1 & 4 at equine show events and sales by multiplex real-time PCR","author":"Yactor J","year":"2006","unstructured":"Yactor J, Lunn KF, Traub-Dargatz JL,  Detection of nasal shedding of EHV-1 & 4 at equine show events and sales by multiplex real-time PCR. In: Proceedings of the 52nd Annual Convention of the American Association of Equine Practitioners. American Association of Equine Practitioners; 2006:223\u2013227."},{"issue":"12","key":"ref3","series-title":"Am J Vet Res","first-page":"1595","article-title":"Risk factors for development of neurologic disease after experimental exposure to equine herpesvirus-1 in horses","volume":"69","author":"Allen GP","year":"2008","unstructured":"Allen GP. Risk factors for development of neurologic disease after experimental exposure to equine herpesvirus-1 in horses. Am J Vet Res. 2008;69(12):1595-1600. doi:10.2460\/ajvr.69.12.1595"},{"issue":"3","key":"ref4","series-title":"J Vet Intern Med","first-page":"601","article-title":"Equine herpesvirus type 1-associated myeloencephalopathy in The Netherlands: a four-year retrospective study (1999-2003)","volume":"20","author":"Goehring LS","year":"2006","unstructured":"Goehring LS, van Winden SC, van Maanen C, Sloet van Oldruitenborgh-Oosterbaan MM. Equine herpesvirus type 1-associated myeloencephalopathy in The Netherlands: a four-year retrospective study (1999-2003). 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Acta Vet Scand. 2013;55(1):19. doi:10.1186\/1751-0147-55-19"},{"issue":"6","key":"ref15","series-title":"Equine Vet J","first-page":"689","article-title":"Quantitative molecular viral loads in 7 horses with naturally occurring equine herpesvirus-1 infection","volume":"47","author":"Estell KE","year":"2015","unstructured":"Estell KE, Dawson DR, Magdesian KG,  Quantitative molecular viral loads in 7 horses with naturally occurring equine herpesvirus-1 infection. Equine Vet J. 2015;47(6):689-693. doi:10.1111\/evj.12351"}],"container-title":["Journal of the American Veterinary Medical Association"],"original-title":[],"link":[{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/aop\/javma.26.02.0118\/javma.26.02.0118.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/aop\/javma.26.02.0118\/javma.26.02.0118.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T16:49:00Z","timestamp":1783702140000},"score":1,"resource":{"primary":{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/aop\/javma.26.02.0118\/javma.26.02.0118.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,10]]},"references-count":15,"URL":"https:\/\/doi.org\/10.2460\/javma.26.02.0118","relation":{},"ISSN":["0003-1488"],"issn-type":[{"value":"0003-1488","type":"print"}],"subject":[],"published":{"date-parts":[[2026,7,10]]}}}