Eastern Equine Encephalomyelitis

Equine Disease Quarterly Newsletter Presorted Standard US Postage Paid 5 Department of Veterinary Science Permit 51 Maxwell H. Gluck Equine Research Center Lexington KY University of Kentucky Lexington, Kentucky 40546-0099

cessfully medicated, it should have limited intense mental management. As a last resort for cases that Address Service Requested exercise during the heat of the day and should do not respond to conventional therapies, moving be accommodated in facilities that minimize an the horse to a geographically less hot and humid increase in body temperature by providing shade, climate may eventually restore its ability to sweat. movement of air, misters, or even cold-water hos- CONTACT: ing. The simplest of treatments is supplementation Dr . Joan Gariboldi with electrolytes based on abnormalities identified (859) 333-5303 OCTOBER 2015 by the blood chemistry combined with environ- jcgariboldi@gmail .com Volume 24, Number 4 Lexington, Kentucky

COMMENTARY KENTUCKY IN THIS ISSUE ore than 100 land-grant colleges and uni- Universities and partners are incorporating rural Mversities have Extension educators who readiness into disaster readiness curricula, which Commentary bring research-based information to agricultural includes specific materials focused on equine issues Manifestations of Equine Herpesvirus–1 International producers and the public, including horse own- before, during, and after disasters strike. Beneath ers. Over the last decade, the university specialists the surface of many of the partnerships you will Second Quarter 2015 ...... 2 and educators involved with both equine science find delegates from EDEN developing, publishing, and disaster education (preparedness, mitigation, and collaborating on new materials on a regular quine herpesvirus-1 (EHV-1) is one of five of impending parturition. The fetus is aborted Getah Virus . . . . . 3 Eherpesviruses commonly found in horses. fresh, in contrast to other causes of abortion such response and recovery) have made significant col- basis. EHV-1 infections manifest in three syndromes: as leptospirosis where the fetus may be significantly National laborative strides in developing and publishing It is imperative that information and resources respiratory, reproductive, and neurologic. Like decomposed. Eastern Equine resource information. These efforts include mate- for horse managers during disasters is both other herpesviruses, EHV-1 can establish latent Following any abortion, the mare should be Encephalomyelitis . . 4 rials on three different platforms: eXtension (the research-based and refereed by experts and civic infections, making it possible for outbreaks of isolated, fetal tissues should be contained and Anhidrosis ...... 4 national Extension website: http://learn.extension. authorities for validity. With the popular nature disease to occur in herds that are considered closed. submitted to a diagnostic laboratory, and in- org), My Horse University (a collaborative effort of horses internationally, valid information that is While quarantine of new arrivals, segregation of contact mares should not be moved nor should liver. Characteristic intranuclear inclusion bodies fests with acute onset ataxia or paresis, often ac- Kentucky between university equine specialists: www.my- readily available is critical when crucial incidents young stock, breeding stock and show stock, and new mares be brought in until a diagnosis has been are frequent. Common ancillary tests for detection companied by weakness, urinary incontinence, Equine horseuniversity.com), and the Extension Disaster are impending or ongoing. No equine manager vaccination are important management tools in rendered. Fetal tissues and uterine fluids should of the virus include fluorescent antibody testing, poor tail and anal tone, and tail elevation, either Herpesvirus-1 . . . . 5 Education Network (EDEN) (collaboration of can afford to be basing response on “popular” or the prevention of EHV-1 infections, complete be considered infectious, and contaminated areas virus isolation, and polymerase chain reaction singly or in combination. EHM can occur as a disaster educators across the United States: www. “web-based” practices or materials during a crisis. protection is not possible to achieve. Vaccination should be cleaned with detergent and disinfected. testing. sporadic case of neurologic disease, but often eden.lsu.edu). In most cases equine managers will have an average confirms relatively short-term immunity (4-5 Contaminated bedding should be bagged and EHV-1 abortions can occur singly or may manifests as an outbreak within a single population Webinars on animal disaster preparedness and of 30 minutes to 2 hours to prepare for a disaster, months) and immunity is not entirely protective, discarded and not spread on pastures. spread rapidly in a susceptible population, leading of horses. Outbreaks are often identified in dense biosecurity are available on eXtension and My although in some cases it can be as little as 15 meaning that even well-vaccinated horses can In the case of EHV-1 abortions, the fetal tissues to the classic “abortion storm.” With improved populations of horses, such as at racetracks, horse Horse University (enter “disaster” in the search minutes. During two floods and seven wildfires develop disease. and fluids contain high concentrations of virus; management and readily available vaccines for shows or show barns, riding stables, etc. Generally, engines), along with a wealth of other equine and in the western United States it took an average of The respiratory form of EHV-1 is generally mild infected foals and mares also shed virus via the EHV-1, the number of cases of EHV-1 abortion these horses are well-vaccinated and vaccination livestock information. The EDEN website is an 15 minutes per horse to respond to disaster if the and self-limiting. Clinical signs are indistinguish- respiratory route. EHV-1 is transmitted via the has declined dramatically over the past 30 years, seems to be neither protective nor a risk factor. extensive information hub that has disaster-specific responders were already equipped and organized. able from other viral causes of respiratory disease, respiratory route and fomites. However, since it with the vast majority of cases being single events. While the pathology of EHM is well-understood, information (e.g., drought, hurricanes, tornadoes, If not ready, the average was closer to one hour per such as equine influenza and EHV-4. Horses is an enveloped virus, herpesvirus is readily inac- EHV-1 confirmed abortions diagnosed at the the production and development of disease is not animal disease), as well as resources for communi- horse. exhibit a fever, cough, serous nasal discharge, and tivated by thorough cleaning with detergents fol- University of Kentucky Veterinary Diagnostic and is the subject of continued research. Prevention ties, families, and children dealing with disasters. For those reasons equine managers should have mild lethargy. lowed by disinfectants. Biosecurity and restricted Laboratory are shown in Figure 3. During that of outbreaks of EHM relies on close observation A notable effort has been the EDEN Strength- a disaster plan, equipment, personnel, evacuation Reproductive disease is generally considered to movement of horses are important in containing same time, EHV-1 neonatal deaths were diagnosed of the horses, including monitoring of rectal tem- ening Community Agrosecurity Preparedness routes, emergency supplies, first-aid kits, and be the most economically important manifestation EHV-1 infections. in 2011 (one), 2012 (two), and 2014 (one). peratures, swift isolation of affected horses, and (S-CAP) program, which is a two-day course that emergency contact information ready at all times. of EHV-1. Infection with EHV-1 causes abortion Laboratory diagnosis relies on gross and histo- Respiratory and reproductive manifestations of often quarantine of the premises. facilitates emergency managers and agriculture/ The eXtension, My Horse University, and EDEN in the last trimester of gestation. Affected foals logic examination in conjunction with laboratory EHV-1 are well-documented and have long been A constant presence in the horse world, EHV-1 livestock owners to evaluate vulnerabilities within resources can help utilize the hard-earned, factual are occasionally born alive but are generally very testing. Gross lesions can include pleural and recognized. While viral latency and the production is well known, but many challenges remain. counties and develop enhanced agrosecurity plans knowledge developed by professionals to reduce of a vaccine that produces long-term immunity weak and succumb within days of birth, often with peritoneal effusion, over-expanded lungs with CONTACT: to address local needs. This process almost always impacts from disasters. Remember: Having a plan secondary disease conditions. The virus infects the rib impressions and small white foci scattered and confirms better protection continue to be Dr . Laura Kennedy includes establishing response and evacuation can save human and animal lives. studied, these syndromes are well understood. (859) 257-8283 guidelines for equine owners. To date, 48 S-CAP mare through the respiratory tract and then enters throughout the liver. However, there are many CONTACT: A manifestation of EHV-1 that is less under- drlaurakennedy@uky .edu the bloodstream (viremia), traveling to and infect- cases in which lesions are not identified at necropsy. University of Kentucky workshops have been conducted, which represent Scott Cotton ing the fetus. Infection in the mare is generally Histologically, EHV-1 produces necrotizing lesions stood is equine herpesvirus myeloencephalopathy Veterinary Diagnostic Laboratory 24 states, 285 counties, and 23.7 million residents. (307) 235-9400 (EHM). EHM is a neurologic disease that mani- Lexington, Kentucky Scotton1@uwyo .edu inapparent and abortion occurs without any signs in a number of organs, most notably the lung and University of Wyoming Extension Area Educator EDEN Agrosecurity Delegate Casper, Wyoming 2 3 4 INTERNATIONAL NATIONAL Second Quarter 2015* Getah Virus: Significance as an Equine Pathogen Figure 1. States with Equine EEE Cases, 2003-2014 . Eastern Equine Encephalomyelitis

he International Collating Centre, New- Two cases of equine coital exanthema were n outbreak of illness at a Japanese racing virus is abortigenic in the pregnant mare or that astern equine encephalomyelitis (EEE) is only Despite the geographic distribution of equine Tmarket, United Kingdom, and other sources diagnosed in the UK. Astable in the latter half of 2014 re-awakened infection can result in congenital abnormalities in Eone of several important vector-borne diseases EEE cases, the rapid interstate and international reported the following disease outbreaks. Germany confirmed equine arteritis virus infec- awareness of Getah virus and its potential as an foals. that is of significant concern to horse owners. With transportation of horses for show, racing, recre- Vesicular stomatitis reoccurred in the USA in tion in two stallions on separate premises. equine pathogen. The first indication that the virus The only other animal species in which Getah a mortality rate of 90%, it is a deadly disease. The ation, sales, breeding, and other activities strongly late April 2015. Infection with the New Jersey A single case of equine adenoviral respiratory could cause illness in horses was the widespread virus has been implicated in causing disease is U.S. Department of Agriculture Animal and Plant supports the use of EEE vaccines. The EEE vac- serotype of the virus had spread to 25 premises in infection in a foal was reported in the USA. occurrence of a disease syndrome among race- swine. The virus has been isolated from newborn Health Inspection Service, Veterinary Services cine is considered by the American Association of Arizona, Colorado, New Mexico, Texas, and Utah. Outbreaks of equine infectious anemia were horses at two training centers in Japan in 1978. piglets that died of peracute disease and also from works with the U.S. Centers for Disease Control Equine Practitioners to be a “core” vaccine. A donkey that strayed across the border from recorded in Canada, France, and the USA. A total Subsequently, the virus was implicated in a clini- dead fetuses removed from a naturally infected sow. and Prevention and public health officials to col- Insect control and appropriate use of approved Mexico into Texas, USA was reported as testing of 16 cases of the disease were diagnosed on nine cally similar disease outbreak on a Thoroughbred Getah virus is primarily a mosquito-borne lect data on EEE and other vector-borne diseases. insecticides are critical to reducing the risks of serologically positive for glanders. The animal was premises in four westernmost provinces in Canada. breeding farm in India during 1990. infection that is transmitted by different species Figure 1 shows the geographic location (shaded EEE as well as West Nile virus infections, vesicular one of a group of five, all of which were clinically A single case was identified in France and three Getah virus is a mosquito-borne arbovirus of Culex and Aedes mosquitoes depending on the states) of equine EEE cases from 2003-2014, al- stomatitis, and other insect-borne diseases. though not every state had cases each year. Figure normal. With the one exception, the remaining cases on different premises in the USA. that is a member of the genus Alphavirus, family geographic region of the world in which it occurs. CONTACT: donkeys were seronegative for antibodies to France and the UAE reported that equine piro- Togaviridae. First isolated from mosquito pools Swine are thought to play a role in amplification Adapted from www.aphis.usda.gov 2 shows reported U.S. equine EEE cases (which Dr . Roberta Dwyer Burkholderia mallei. The positive donkey, whose plasmosis was endemic; Switzerland confirmed one collected in Sarawak (Malaysia) between 1968 of the virus in endemic areas. The potential for include presumptive positive and confirmed posi- (859) 218-1122 tive cases) from 2003-2014. rmdwyer@uky .edu status was downgraded to suspect on re-test, was case of the disease. and 1970, Getah or one of its antigenically related transmission through direct horse-to-horse contact Maxwell H . Gluck Equine Research Center euthanized. Contagious equine metritis was diagnosed in viruses, can be found over a wide geographic range cannot be discounted considering some acutely Figure 2. Reported U .S . Equine EEE Cases . University of Kentucky extending from Eurasia to Australia. Results of infected horses shed significant quantities of infec- Lexington, Kentucky Equine Disease Quarterly Several outbreaks of strangles were reported in three horses on separate premises in Germany. 800 Denmark, France, Germany, Switzerland, United The USA reported isolated cases of nocardio- serologic surveys have confirmed infection in tious virus into the respiratory tract. 700 Editors Arab Emirates (UAE), and the USA. form placentitis and abortion in two states and a humans and a wide diversity of domestic and Diagnosis of Getah virus infection can be read- Roberta Dwyer 600 Alan Loynachan Equine influenza was reported by Germany single case of mare reproductive loss syndrome in wildlife animal species wherever the virus is pres- ily accomplished by virus detection in nasal swabs, Anhidrosis Peter Timoney (single cases on four premises), the UK (seven out- Kentucky. ent. Serologic evidence of Getah virus activity unclotted blood (buffy coat) samples, and saliva 500 breaks including some animals recently imported), Outbreaks of salmonellosis were confirmed in in horses in Japan can be traced back to 1961. either by PCR assay or virus isolation. It can also 400 Staff nhidrosis is a common condition that fre- at a diagnosis. Clinical signs of partial anhidrosis Diane Furry and the USA (outbreaks in four states). the USA, some due to Group B Salmonella spp. Subsequent studies have shown that the infection be confirmed by serological testing of acute and 300 quently presents during the long, hot days of include an elevated respiratory rate and increased Tawana Brown Equine herpesvirus-1 and -4 (EHV-1, -4) re- and others to Group C1 Salmonella spp. France was widespread in equine populations throughout convalescent serum samples. Because of the close 200 A Dennis Duross summer and is the inability of the horse to produce rectal temperature that requires an extended period lated diseases were reported in France, Germany, reported five outbreaks of rotavirus infection in that country. Notwithstanding this fact, however, clinical similarity between Getah virus infection 100 an adequate amount of sweat. The decreased abil- of time (greater than 30 minutes) to return to the Ireland, Japan, Switzerland, the UK, and the USA. foals. Clostridiosis in foals was recorded in the disease events caused by Getah virus have been and equine viral arteritis and African horse sick- 0 ity to maintain proper body temperature limits normal range upon cessation of exercise. Correspondence should be Respiratory disease was recorded by France (three USA, several associated with C. perfringens Toxin very infrequent. ness, it is important to differentiate it diagnostically 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 athletic potential, increases risk for heat stroke, and Chronic cases of anhidrosis typically present addressed to the editors, outbreaks), Germany (two cases), Ireland (three Type A and others with C. difficile Toxin A/B gene Naturally occurring disease caused by Getah from either of these two diseases. Department of Veterinary Year www.aphis.usda.gov may compound other disease processes. The cause with a poor, dry-looking hair coat accompanied by Science, Maxwell H . Gluck cases), and the USA (several states). Abortion strains. virus has only been reported in horses and in swine. Prevention and control of Getah virus infection of anhidrosis is not well defined, but is believed a history of lethargy during the hotter times of the Equine Research Center, due to EHV-1 was confirmed by France (three Nine cases of Eastern equine encephalomyeli- While the vast majority of primary infections in is based on measures to reduce mosquito contact University of Kentucky, to involve over-stimulation of the horse’s sweat year. It should be noted that any horse may suffer outbreaks), Germany (nine cases), Japan (seven tis were diagnosed in the USA, the majority in horses are asymptomatic, on occasion the virus with horses and, optimally, vaccination of at-risk Lexington, Kentucky USA, glands by stress hormones, typically occurring in from anhidrosis in the summer months, including 40546-0099 cases of abortion and three deaths in neonatal Florida, four of which had not been vaccinated can give rise to extensive outbreaks of mild illness equine populations in countries in which the virus Telephone (859) 257-4757 the summer months. A horse may only have minor brood mares and retired performance horses with foals on seven premises), the UK (one case), and against the disease. The USA also reported one case characterized by fever, anorexia, serous nasal dis- is endemic. Fax (859) 257-8542 Figure 3. Abortions submitted to UKVDL, 2011-2015 . decreases in sweat production, resulting in subtle more sedentary lifestyles. Affected horses will have the USA (three cases). EHV-1 neurologic disease of West Nile encephalitis in a horse in Oklahoma. charge, hind limb edema, stiff gait, scrotal edema, While Getah virus is not considered an im- clinical signs, or a total loss of sweat production an elevated respiratory rate at rest and will tend to Internet address: was reported by Germany (two cases) and the USA Rhodococcal related disease was recorded in submandibular lymphadenopathy, and urticarial portant equine pathogen, it can be significantly http://www .ca .uky .edu/ 400 and severe signs of hyperthermia. Most commonly seek shade if available. gluck/index .htm (outbreaks in seven states, the majority involving Switzerland (single case) and the USA (numerous skin rash. Affected horses may develop some or all disruptive when extensive outbreaks occur. 350 * diagnosed in performance horses, it also affects A definitive diagnosis of anhidrosis can be made isolated cases of the disease). Respiratory disease cases in multiple states in which the disease is of these clinical signs. Regardless of severity, the Material published in the CONTACT: 300 non-performance horses and seems to be more by injecting a series of dilutions of terbutaline. Quarterly is not subject to due to EHV-4 was recorded in France (11 out- endemic). disease is non-fatal and complete clinical recovery Dr . Peter Timoney copyright . Permission is (859) 218-1094 250 prevalent in dark-colored animals. Anhidrosis can This may be useful in determining severity of the breaks), Germany (three cases), Switzerland (one Isolated cases of other diseases were reported: occurs within 7 to 14 days. Symptomatic treat- Abortions Total therefore granted to Total be especially problematic in animals with coexist- condition and evaluating response to treatment. case), and the UK (five outbreaks, one involving Tyzzer’s disease (single case in a foal in the USA), ment is seldom indicated. Based on the outbreak ptimoney@uky .edu reproduce articles, although Maxwell H . Gluck Equine Research Center EHV-1 ing medical diseases (e.g. metabolic or respiratory Blood work, including an electrolyte analysis, may acknowledgment of the multiple cases). The UK also reported one case of melioidosis (single case in a riding-school horse in recorded in India, there was no evidence that Getah 15 University of Kentucky conditions) by increasing cortisol levels and respi- also be helpful in formulating a treatment plan. source and author is re- EHV-4 related abortion. Singapore), cutaneous leishmaniasis (single case Lexington, Kentucky quested . 10 ratory demands. Lastly, a skin biopsy may be performed in severe in Switzerland), and anaplasmosis (two cases in 5 The most common form seen is incomplete cases to evaluate the histologic structure of the The University of Kentucky Germany). is an Equal Opportunity 0 or partial anhidrosis and should be considered sweat glands, however, this is rarely necessary to Organization . Abortions EHV-1 2011 2012 2013 2014 2015 if a decline in performance with an increase in confirm a diagnosis. *First Quarter Report from Australia Foaling Season ambient temperature during summer months There are some treatment options for anhidro- * Submissions for 2011 were subsidized, resulting in an in ated occurs. A complete history and clinical examina- sis, and what works on one horse might not work Printed on recycled paper number of cases. tion following exercise may be adequate to arrive on another. Until the horse with anhidrosis is suc- 2 3 4 INTERNATIONAL NATIONAL Second Quarter 2015* Getah Virus: Significance as an Equine Pathogen Figure 1. States with Equine EEE Cases, 2003-2014 . Eastern Equine Encephalomyelitis

he International Collating Centre, New- Two cases of equine coital exanthema were n outbreak of illness at a Japanese racing virus is abortigenic in the pregnant mare or that astern equine encephalomyelitis (EEE) is only Despite the geographic distribution of equine Tmarket, United Kingdom, and other sources diagnosed in the UK. Astable in the latter half of 2014 re-awakened infection can result in congenital abnormalities in Eone of several important vector-borne diseases EEE cases, the rapid interstate and international reported the following disease outbreaks. Germany confirmed equine arteritis virus infec- awareness of Getah virus and its potential as an foals. that is of significant concern to horse owners. With transportation of horses for show, racing, recre- Vesicular stomatitis reoccurred in the USA in tion in two stallions on separate premises. equine pathogen. The first indication that the virus The only other animal species in which Getah a mortality rate of 90%, it is a deadly disease. The ation, sales, breeding, and other activities strongly late April 2015. Infection with the New Jersey A single case of equine adenoviral respiratory could cause illness in horses was the widespread virus has been implicated in causing disease is U.S. Department of Agriculture Animal and Plant supports the use of EEE vaccines. The EEE vac- serotype of the virus had spread to 25 premises in infection in a foal was reported in the USA. occurrence of a disease syndrome among race- swine. The virus has been isolated from newborn Health Inspection Service, Veterinary Services cine is considered by the American Association of Arizona, Colorado, New Mexico, Texas, and Utah. Outbreaks of equine infectious anemia were horses at two training centers in Japan in 1978. piglets that died of peracute disease and also from works with the U.S. Centers for Disease Control Equine Practitioners to be a “core” vaccine. A donkey that strayed across the border from recorded in Canada, France, and the USA. A total Subsequently, the virus was implicated in a clini- dead fetuses removed from a naturally infected sow. and Prevention and public health officials to col- Insect control and appropriate use of approved Mexico into Texas, USA was reported as testing of 16 cases of the disease were diagnosed on nine cally similar disease outbreak on a Thoroughbred Getah virus is primarily a mosquito-borne lect data on EEE and other vector-borne diseases. insecticides are critical to reducing the risks of serologically positive for glanders. The animal was premises in four westernmost provinces in Canada. breeding farm in India during 1990. infection that is transmitted by different species Figure 1 shows the geographic location (shaded EEE as well as West Nile virus infections, vesicular one of a group of five, all of which were clinically A single case was identified in France and three Getah virus is a mosquito-borne arbovirus of Culex and Aedes mosquitoes depending on the states) of equine EEE cases from 2003-2014, al- stomatitis, and other insect-borne diseases. though not every state had cases each year. Figure normal. With the one exception, the remaining cases on different premises in the USA. that is a member of the genus Alphavirus, family geographic region of the world in which it occurs. CONTACT: donkeys were seronegative for antibodies to France and the UAE reported that equine piro- Togaviridae. First isolated from mosquito pools Swine are thought to play a role in amplification Adapted from www.aphis.usda.gov 2 shows reported U.S. equine EEE cases (which Dr . Roberta Dwyer Burkholderia mallei. The positive donkey, whose plasmosis was endemic; Switzerland confirmed one collected in Sarawak (Malaysia) between 1968 of the virus in endemic areas. The potential for include presumptive positive and confirmed posi- (859) 218-1122 tive cases) from 2003-2014. rmdwyer@uky .edu status was downgraded to suspect on re-test, was case of the disease. and 1970, Getah or one of its antigenically related transmission through direct horse-to-horse contact Maxwell H . Gluck Equine Research Center euthanized. Contagious equine metritis was diagnosed in viruses, can be found over a wide geographic range cannot be discounted considering some acutely Figure 2. Reported U .S . Equine EEE Cases . University of Kentucky extending from Eurasia to Australia. Results of infected horses shed significant quantities of infec- Lexington, Kentucky Equine Disease Quarterly Several outbreaks of strangles were reported in three horses on separate premises in Germany. 800 Denmark, France, Germany, Switzerland, United The USA reported isolated cases of nocardio- serologic surveys have confirmed infection in tious virus into the respiratory tract. 700 Editors Arab Emirates (UAE), and the USA. form placentitis and abortion in two states and a humans and a wide diversity of domestic and Diagnosis of Getah virus infection can be read- Roberta Dwyer 600 Alan Loynachan Equine influenza was reported by Germany single case of mare reproductive loss syndrome in wildlife animal species wherever the virus is pres- ily accomplished by virus detection in nasal swabs, Anhidrosis Peter Timoney (single cases on four premises), the UK (seven out- Kentucky. ent. Serologic evidence of Getah virus activity unclotted blood (buffy coat) samples, and saliva 500 breaks including some animals recently imported), Outbreaks of salmonellosis were confirmed in in horses in Japan can be traced back to 1961. either by PCR assay or virus isolation. It can also 400 Staff nhidrosis is a common condition that fre- at a diagnosis. Clinical signs of partial anhidrosis Diane Furry and the USA (outbreaks in four states). the USA, some due to Group B Salmonella spp. Subsequent studies have shown that the infection be confirmed by serological testing of acute and 300 quently presents during the long, hot days of include an elevated respiratory rate and increased Tawana Brown Equine herpesvirus-1 and -4 (EHV-1, -4) re- and others to Group C1 Salmonella spp. France was widespread in equine populations throughout convalescent serum samples. Because of the close 200 A Dennis Duross summer and is the inability of the horse to produce rectal temperature that requires an extended period lated diseases were reported in France, Germany, reported five outbreaks of rotavirus infection in that country. Notwithstanding this fact, however, clinical similarity between Getah virus infection 100 an adequate amount of sweat. The decreased abil- of time (greater than 30 minutes) to return to the Ireland, Japan, Switzerland, the UK, and the USA. foals. Clostridiosis in foals was recorded in the disease events caused by Getah virus have been and equine viral arteritis and African horse sick- 0 ity to maintain proper body temperature limits normal range upon cessation of exercise. Correspondence should be Respiratory disease was recorded by France (three USA, several associated with C. perfringens Toxin very infrequent. ness, it is important to differentiate it diagnostically 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 athletic potential, increases risk for heat stroke, and Chronic cases of anhidrosis typically present addressed to the editors, outbreaks), Germany (two cases), Ireland (three Type A and others with C. difficile Toxin A/B gene Naturally occurring disease caused by Getah from either of these two diseases. Department of Veterinary Year www.aphis.usda.gov may compound other disease processes. The cause with a poor, dry-looking hair coat accompanied by Science, Maxwell H . Gluck cases), and the USA (several states). Abortion strains. virus has only been reported in horses and in swine. Prevention and control of Getah virus infection of anhidrosis is not well defined, but is believed a history of lethargy during the hotter times of the Equine Research Center, due to EHV-1 was confirmed by France (three Nine cases of Eastern equine encephalomyeli- While the vast majority of primary infections in is based on measures to reduce mosquito contact University of Kentucky, to involve over-stimulation of the horse’s sweat year. It should be noted that any horse may suffer outbreaks), Germany (nine cases), Japan (seven tis were diagnosed in the USA, the majority in horses are asymptomatic, on occasion the virus with horses and, optimally, vaccination of at-risk Lexington, Kentucky USA, glands by stress hormones, typically occurring in from anhidrosis in the summer months, including 40546-0099 cases of abortion and three deaths in neonatal Florida, four of which had not been vaccinated can give rise to extensive outbreaks of mild illness equine populations in countries in which the virus Telephone (859) 257-4757 the summer months. A horse may only have minor brood mares and retired performance horses with foals on seven premises), the UK (one case), and against the disease. The USA also reported one case characterized by fever, anorexia, serous nasal dis- is endemic. Fax (859) 257-8542 Figure 3. Abortions submitted to UKVDL, 2011-2015 . decreases in sweat production, resulting in subtle more sedentary lifestyles. Affected horses will have the USA (three cases). EHV-1 neurologic disease of West Nile encephalitis in a horse in Oklahoma. charge, hind limb edema, stiff gait, scrotal edema, While Getah virus is not considered an im- clinical signs, or a total loss of sweat production an elevated respiratory rate at rest and will tend to Internet address: was reported by Germany (two cases) and the USA Rhodococcal related disease was recorded in submandibular lymphadenopathy, and urticarial portant equine pathogen, it can be significantly http://www .ca .uky .edu/ 400 and severe signs of hyperthermia. Most commonly seek shade if available. gluck/index .htm (outbreaks in seven states, the majority involving Switzerland (single case) and the USA (numerous skin rash. Affected horses may develop some or all disruptive when extensive outbreaks occur. 350 * diagnosed in performance horses, it also affects A definitive diagnosis of anhidrosis can be made isolated cases of the disease). Respiratory disease cases in multiple states in which the disease is of these clinical signs. Regardless of severity, the Material published in the CONTACT: 300 non-performance horses and seems to be more by injecting a series of dilutions of terbutaline. Quarterly is not subject to due to EHV-4 was recorded in France (11 out- endemic). disease is non-fatal and complete clinical recovery Dr . Peter Timoney copyright . Permission is (859) 218-1094 250 prevalent in dark-colored animals. Anhidrosis can This may be useful in determining severity of the breaks), Germany (three cases), Switzerland (one Isolated cases of other diseases were reported: occurs within 7 to 14 days. Symptomatic treat- Abortions Total therefore granted to Total be especially problematic in animals with coexist- condition and evaluating response to treatment. case), and the UK (five outbreaks, one involving Tyzzer’s disease (single case in a foal in the USA), ment is seldom indicated. Based on the outbreak ptimoney@uky .edu reproduce articles, although Maxwell H . Gluck Equine Research Center EHV-1 ing medical diseases (e.g. metabolic or respiratory Blood work, including an electrolyte analysis, may acknowledgment of the multiple cases). The UK also reported one case of melioidosis (single case in a riding-school horse in recorded in India, there was no evidence that Getah 15 University of Kentucky conditions) by increasing cortisol levels and respi- also be helpful in formulating a treatment plan. source and author is re- EHV-4 related abortion. Singapore), cutaneous leishmaniasis (single case Lexington, Kentucky quested . 10 ratory demands. Lastly, a skin biopsy may be performed in severe in Switzerland), and anaplasmosis (two cases in 5 The most common form seen is incomplete cases to evaluate the histologic structure of the The University of Kentucky Germany). is an Equal Opportunity 0 or partial anhidrosis and should be considered sweat glands, however, this is rarely necessary to Organization . Abortions EHV-1 2011 2012 2013 2014 2015 if a decline in performance with an increase in confirm a diagnosis. *First Quarter Report from Australia Foaling Season ambient temperature during summer months There are some treatment options for anhidro- * Submissions for 2011 were subsidized, resulting in an in ated occurs. A complete history and clinical examina- sis, and what works on one horse might not work Printed on recycled paper number of cases. tion following exercise may be adequate to arrive on another. Until the horse with anhidrosis is suc- Equine Disease Quarterly Newsletter Presorted Standard US Postage Paid 5 Department of Veterinary Science Permit 51 Maxwell H. Gluck Equine Research Center Lexington KY University of Kentucky Lexington, Kentucky 40546-0099

COMMENTARY KENTUCKY IN THIS ISSUE ore than 100 land-grant colleges and uni- Universities and partners are incorporating rural Mversities have Extension educators who readiness into disaster readiness curricula, which Commentary bring research-based information to agricultural includes specific materials focused on equine issues Manifestations of Equine Herpesvirus–1 International producers and the public, including horse own- before, during, and after disasters strike. Beneath ers. Over the last decade, the university specialists the surface of many of the partnerships you will Second Quarter 2015 ...... 2 and educators involved with both equine science find delegates from EDEN developing, publishing, and disaster education (preparedness, mitigation, and collaborating on new materials on a regular quine herpesvirus-1 (EHV-1) is one of five of impending parturition. The fetus is aborted Getah Virus . . . . . 3 Eherpesviruses commonly found in horses. fresh, in contrast to other causes of abortion such response and recovery) have made significant col- basis. EHV-1 infections manifest in three syndromes: as leptospirosis where the fetus may be significantly National laborative strides in developing and publishing It is imperative that information and resources respiratory, reproductive, and neurologic. Like decomposed. Eastern Equine resource information. These efforts include mate- for horse managers during disasters is both other herpesviruses, EHV-1 can establish latent Following any abortion, the mare should be Encephalomyelitis . . 4 rials on three different platforms: eXtension (the research-based and refereed by experts and civic infections, making it possible for outbreaks of isolated, fetal tissues should be contained and Anhidrosis ...... 4 national Extension website: http://learn.extension. authorities for validity. With the popular nature disease to occur in herds that are considered closed. submitted to a diagnostic laboratory, and in- org), My Horse University (a collaborative effort of horses internationally, valid information that is While quarantine of new arrivals, segregation of contact mares should not be moved nor should liver. Characteristic intranuclear inclusion bodies fests with acute onset ataxia or paresis, often ac- Kentucky between university equine specialists: www.my- readily available is critical when crucial incidents young stock, breeding stock and show stock, and new mares be brought in until a diagnosis has been are frequent. Common ancillary tests for detection companied by weakness, urinary incontinence, Equine horseuniversity.com), and the Extension Disaster are impending or ongoing. No equine manager vaccination are important management tools in rendered. Fetal tissues and uterine fluids should of the virus include fluorescent antibody testing, poor tail and anal tone, and tail elevation, either Herpesvirus-1 . . . . 5 Education Network (EDEN) (collaboration of can afford to be basing response on “popular” or the prevention of EHV-1 infections, complete be considered infectious, and contaminated areas virus isolation, and polymerase chain reaction singly or in combination. EHM can occur as a disaster educators across the United States: www. “web-based” practices or materials during a crisis. protection is not possible to achieve. Vaccination should be cleaned with detergent and disinfected. testing. sporadic case of neurologic disease, but often eden.lsu.edu). In most cases equine managers will have an average confirms relatively short-term immunity (4-5 Contaminated bedding should be bagged and EHV-1 abortions can occur singly or may manifests as an outbreak within a single population Webinars on animal disaster preparedness and of 30 minutes to 2 hours to prepare for a disaster, months) and immunity is not entirely protective, discarded and not spread on pastures. spread rapidly in a susceptible population, leading of horses. Outbreaks are often identified in dense biosecurity are available on eXtension and My although in some cases it can be as little as 15 meaning that even well-vaccinated horses can In the case of EHV-1 abortions, the fetal tissues to the classic “abortion storm.” With improved populations of horses, such as at racetracks, horse Horse University (enter “disaster” in the search minutes. During two floods and seven wildfires develop disease. and fluids contain high concentrations of virus; management and readily available vaccines for shows or show barns, riding stables, etc. Generally, engines), along with a wealth of other equine and in the western United States it took an average of The respiratory form of EHV-1 is generally mild infected foals and mares also shed virus via the EHV-1, the number of cases of EHV-1 abortion these horses are well-vaccinated and vaccination livestock information. The EDEN website is an 15 minutes per horse to respond to disaster if the and self-limiting. Clinical signs are indistinguish- respiratory route. EHV-1 is transmitted via the has declined dramatically over the past 30 years, seems to be neither protective nor a risk factor. extensive information hub that has disaster-specific responders were already equipped and organized. able from other viral causes of respiratory disease, respiratory route and fomites. However, since it with the vast majority of cases being single events. While the pathology of EHM is well-understood, information (e.g., drought, hurricanes, tornadoes, If not ready, the average was closer to one hour per such as equine influenza and EHV-4. Horses is an enveloped virus, herpesvirus is readily inac- EHV-1 confirmed abortions diagnosed at the the production and development of disease is not animal disease), as well as resources for communi- horse. exhibit a fever, cough, serous nasal discharge, and tivated by thorough cleaning with detergents fol- University of Kentucky Veterinary Diagnostic and is the subject of continued research. Prevention ties, families, and children dealing with disasters. For those reasons equine managers should have mild lethargy. lowed by disinfectants. Biosecurity and restricted Laboratory are shown in Figure 3. During that of outbreaks of EHM relies on close observation A notable effort has been the EDEN Strength- a disaster plan, equipment, personnel, evacuation Reproductive disease is generally considered to movement of horses are important in containing same time, EHV-1 neonatal deaths were diagnosed of the horses, including monitoring of rectal tem- ening Community Agrosecurity Preparedness routes, emergency supplies, first-aid kits, and be the most economically important manifestation EHV-1 infections. in 2011 (one), 2012 (two), and 2014 (one). peratures, swift isolation of affected horses, and (S-CAP) program, which is a two-day course that emergency contact information ready at all times. of EHV-1. Infection with EHV-1 causes abortion Laboratory diagnosis relies on gross and histo- Respiratory and reproductive manifestations of often quarantine of the premises. facilitates emergency managers and agriculture/ The eXtension, My Horse University, and EDEN in the last trimester of gestation. Affected foals logic examination in conjunction with laboratory EHV-1 are well-documented and have long been A constant presence in the horse world, EHV-1 livestock owners to evaluate vulnerabilities within resources can help utilize the hard-earned, factual are occasionally born alive but are generally very testing. Gross lesions can include pleural and recognized. While viral latency and the production is well known, but many challenges remain. counties and develop enhanced agrosecurity plans knowledge developed by professionals to reduce of a vaccine that produces long-term immunity weak and succumb within days of birth, often with peritoneal effusion, over-expanded lungs with CONTACT: to address local needs. This process almost always impacts from disasters. Remember: Having a plan secondary disease conditions. The virus infects the rib impressions and small white foci scattered and confirms better protection continue to be Dr . Laura Kennedy includes establishing response and evacuation can save human and animal lives. studied, these syndromes are well understood. (859) 257-8283 guidelines for equine owners. To date, 48 S-CAP mare through the respiratory tract and then enters throughout the liver. However, there are many CONTACT: A manifestation of EHV-1 that is less under- drlaurakennedy@uky .edu the bloodstream (viremia), traveling to and infect- cases in which lesions are not identified at necropsy. University of Kentucky workshops have been conducted, which represent Scott Cotton ing the fetus. Infection in the mare is generally Histologically, EHV-1 produces necrotizing lesions stood is equine herpesvirus myeloencephalopathy Veterinary Diagnostic Laboratory 24 states, 285 counties, and 23.7 million residents. (307) 235-9400 (EHM). EHM is a neurologic disease that mani- Lexington, Kentucky Scotton1@uwyo .edu inapparent and abortion occurs without any signs in a number of organs, most notably the lung and University of Wyoming Extension Area Educator EDEN Agrosecurity Delegate Casper, Wyoming Equine Disease Quarterly Newsletter Presorted Standard US Postage Paid 5 Department of Veterinary Science Permit 51 Maxwell H. Gluck Equine Research Center Lexington KY University of Kentucky Lexington, Kentucky 40546-0099