b'Arizona Ask the VetREAL COUNTRYthe magazine EHV/EHM 101Mike Barna E HV stands for Equine Herpesvirus. There are 9WHAT IS EHM?different EHVs that have been identified. EHV- Equine Herpesvirus Myeloencephalopathy (EHM) Publisher 1 is the type that causes neurologic disease.is the neurologic form of herpes. EHM cases may EHV-1 can also cause respiratory disease, abortion,occur as one isolated case or as an outbreak affecting ArizonaRealCountryMagazine@gmail.com and neonatal death. EHV-4 most commonlymultiple exposed horses. Outbreaks of EHM may causes respiratory disease and is very uncommonlyor may not be associated with an EHV-associated Erika Smith Royal associated with abortion or neurologic disease.respiratory outbreak. With the neurologic form, Almost all horses have been infected with EHV-1 bythere are typically minimal respiratory signs, with Editor two years of age and have no serious clinical effects.a fever greater than 101.5 degrees F being the erika963realcountry@gmail.com Once a horse is infected, the virus can becomeonly warning sign. The neurologic disease appears inactive in the body resulting in a carrier state withsuddenly and is usually rapidly progressing, no external signs of disease. The latent virus canreaching its peak intensity within 24 to 48 hours Misty Voitovski be reactivated duringfrom the onset of Creative Director times of stress, such asinitial neurologic signs. with long-distance travelClinical signs of the or strenuous exercise.neurologic disease may Contributing Writers Current estimates areinclude nasal discharge, that at least 60% ofincoordination, hind Lee Anderson, Bethany Braley, horses have a latentlimb weakness, loss of Justin Legler, Mark Melkowski,EHV-1 infection. tail tone, lethargy, urine Betsy Nunn, Jim Olson,dribbling, head tilt, Alan Rockman, Bob Roloff,SPREADING EHV leaning against a fence or Herpesvirus is primarilywall to maintain balance John Samsill, Hank Sheffer,spread by direct horse- and an inability to rise.Buddy Uldrikson, Grace Webb,to-horse contact by the Michele Wilson transfer of respiratoryDIAGNOSING EHMsecretions like nasalEHV can cause discharge. It is notinflammation of the 801 W. Wickenburg Way known exactly howblood vessels supplying far the aerosolizedthe spinal cord and Wickenburg, AZ 85390 virus can spread, butbrain. The neurologic 30 yards is typicallysigns result from that (602) 254-6644 considered the maximalinflammation and small distance EHV-infectedblood clots that affect the ArizonaRealCountry.com droplets can travelnervous tissue. During after a cough or sneeze.an outbreak of EHM, The virus can also beusually, only 10% of spread by contaminated hands, clothing, buckets,infected horses develop neurologic signs, but this tack, grooming equipment, feed, and trailers. Theproportion is occasionally much higher. It is still virus can survive up to 7 days in the environmentnot fully understood why some horses get EHM and under normal circumstances but can remainothers dont, but it is likely a combination of factors alive for a maximum of one month under perfectspecific to that individual horse and to the strain of environmental conditions.EHV infecting it.Follow Arizona RealThe most important measure is to first cleanHorses with a fever and neurologic signs should be Country for news, events,equipment and horse housing areas. Cleaning firsttested by your veterinarian. Currently recommended allows for the removal of organic material whichtesting consists of a nasal swab and blood sample to giveaways and more! makes the disinfectants more effective. After cleaningdetect the virus by polymerase chain reaction (PCR) the surface, follow with a disinfection process. Thewhich detects the DNA of the virus. Both samples virus is easily killed in the environment by mostshould be submitted to maximize the likelihood of a Arizona Real Country is owned anddisinfectants. It is also important to perform handcorrect diagnosis. Blood samples should be collected published by Barna Broadcastinghygiene by washing hands with soap and dryingtwo to three weeks apart for levels of antibodies LLC. No person, organization or partythoroughly or using an alcohol-based hand sanitizerspecific to EHV-1. can copy or reproduce the contentwhen moving between horses. TREATMENT FOR EHMon our website and/or magazine orSIGNS OF EHV Treatment is primarily supportive. This includes any part of this publication withoutAfter infection, the incubation period may be asanti-inflammatory and anticoagulant drugs, and a written consent from the editorsshort as 24 hours, it is typically four to six days, butintravenous fluids if the horse is having trouble panel and the author of the content, ascan be longer. EHV-1 typically causes a two-phasedrinking. Nursing care is also extremely important applicable. The publisher, authors andfever peaking on day one or two and again on dayif the horse is unable to rise. Antibiotics are not contributors reserve their rights withsix or seven. With respiratory infections there iseffective but can be used if there is a secondary regards to copyright of their work. often substantial nasal and ocular discharge, butbacterial infection. Antiviral drugs such as not a lot of coughing. There may be some persistentvalacyclovir may prevent infection in exposed horses enlargement of the lymph nodes under the jaw.if given before the onset of fever.continued on page 7ArizonaRealCountry.com February 2020 5'