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DETECTION OF ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS 1A IN ARCHIVAL TISSUE USING RNASCOPE ® IN SITU HYBRIDIZATION. J Zoo Wildl Med 2023; 53:661-669. [PMID: 36640067 DOI: 10.1638/2022-0042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2022] [Indexed: 01/09/2023] Open
Abstract
Hemorrhagic disease due to elephant endotheliotropic herpesvirus infection (EEHV-HD) is an important cause of calf mortality in managed and free-ranging Asian (Elephas maximus) and African elephant (Loxodonta spp.) populations. Consequently, infection has profound implications for elephant population growth and sustainability. The mechanisms of disease caused by EEHV (i.e., infection, dissemination, shedding, latency) are relatively undefined, in part because of a lack of robust validated assays for detecting viral gene products in relevant samples. To address this issue, we used RNAscope® in situ hybridization (ISH) based on EEHV1A DNA polymerase and terminase genes to detect EEHV1A RNA in archival formalin-fixed, paraffin-embedded Asian elephant heart and tongue from PCR-confirmed cases (n = 4) of EEHV-HD and Asian elephants (n = 2) that died from other causes. EEHV1A-positive cases had positive hybridization signal in endothelial cell nuclei of both tissues for both DNA polymerase and terminase. EEHV-negative cases lacked signal. In positive cases, the number of positive nuclei was manually assessed to provide an estimate of the viral load and compare sensitivity of the two probes. In all cases, heart had greater signal than tongue for both probes (Wilcoxon rank test; P ≤ 0.01). Overall, terminase hybridization signal was greater than DNA polymerase signal (Wilcoxon rank test; P ≤ 0.01). Results indicate RNAscope ISH is a valuable tool for detection of EEHV in archival samples and for confirming infection. Additionally, the terminase gene is the optimal target and heart is preferable to tongue for detection in cases of EEHV-HD. Results will inform future investigations of viral tropism in EEHV-HD cases due to EEHV1A.
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Yang N, Bao M, Zhu B, Shen Q, Guo X, Li W, Tang R, Zhu D, Tang Y, Phalen DN, Zhang L. Elephant Endotheliotropic Herpesvirus 1, 4 and 5 in China: Occurrence in Multiple Sample Types and Implications for Wild and Captive Population Surveillance. Viruses 2022; 14:v14020411. [PMID: 35216004 PMCID: PMC8875873 DOI: 10.3390/v14020411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/13/2022] [Accepted: 02/15/2022] [Indexed: 02/05/2023] Open
Abstract
Elephant endotheliotropic herpesviruses (EEHVs) are important causes of death in both captive and wild Asian elephants (Elephas maximus). Nothing is known about the prevalence of EEHVs in wild or domestic elephants in China. To determine if EEHVs are present in elephants in China, 126 wild elephants from three populations and 202 captive individuals from zoos (n = 155) and the Wild Elephant Valley (n = 47) were screened using semi-nested polymerase chain reaction assays with EEHV-redundant and EEHV1/4/5-specific primers. EEHV1B and EEHV4 were detected in samples from both wild (EEHV1B:8/126; EEHV4:2/126) and captive (EEHV1B:5/155; EEHV4:9/155) elephants, while EEHV1A (six cases) and EEHV5 (one case) were only present in the captive elephants from the Wild Elephant Valley. EEHV1 was detected in blood and trunk and oral swabs; EEHV4 was detected in trunk and oral swabs as well as feces; EEHV5 was found in trunk and oral swabs. No significant age or sex association with EEHV1A, EEHV1B, or EEHV5 positivity was observed. An age association with EEHV4 positivity was found, with all unweaned elephants being EEHV4 positive, but an association with the sex of the elephant was not observed. These findings represent the first documentation of EEHV presence in captive and wild elephants in China. These findings also document EEHV1B and EEHV4 shedding in feces and demonstrate the utility of fecal screening as a tool for investigating EEHV4 infection in wild populations of elephants. It is recommended that EEHV testing be included in surveillance programs for captive and wild elephants in China.
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Affiliation(s)
- Nian Yang
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (N.Y.); (B.Z.); (R.T.); (D.Z.); (Y.T.)
| | - Mingwei Bao
- Wild Elephant Valley, Jinghong 666100, China;
| | - Biru Zhu
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (N.Y.); (B.Z.); (R.T.); (D.Z.); (Y.T.)
| | - Qingzhong Shen
- Ecotourism Management Institute of Yunnan Xishuangbanna National Nature Reserve, Jinghong 666100, China;
| | - Xianming Guo
- Research Institute of Xishuangbanna National Nature Reserve, Jinghong 666100, China;
| | - Wenwen Li
- Key Laboratory of Coastal Science and Integrated Management, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China;
| | - Ruchun Tang
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (N.Y.); (B.Z.); (R.T.); (D.Z.); (Y.T.)
| | - Di Zhu
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (N.Y.); (B.Z.); (R.T.); (D.Z.); (Y.T.)
| | - Yinpu Tang
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (N.Y.); (B.Z.); (R.T.); (D.Z.); (Y.T.)
| | - David N. Phalen
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, NSW 2006, Australia
- Schubot Exotic Bird Health Center, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 701 Farm to Market 2818 Service Road, College Station, TX 77840, USA
- Correspondence: (D.N.P.); (L.Z.)
| | - Li Zhang
- Key Laboratory for Biodiversity and Ecological Engineering of Ministry of Education, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (N.Y.); (B.Z.); (R.T.); (D.Z.); (Y.T.)
- Correspondence: (D.N.P.); (L.Z.)
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Prompiram P, Wiriyarat W, Bhusri B, Paungpin W, Jairak W, Sripiboon S, Wongtawan T. The occurrence of elephant endotheliotropic herpesvirus infection in wild and captive Asian elephants in Thailand: Investigation based on viral DNA and host antibody. Vet World 2021; 14:545-550. [PMID: 33776322 PMCID: PMC7994120 DOI: 10.14202/vetworld.2021.545-550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/21/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND AIM Elephant endotheliotropic herpesvirus (EEHV) is a serious disease, threatening the life of young elephants. Many elephants have been infected with no clinical signs and may serve as carriers spreading this disease. It is important to monitor the disease through clinical signs and molecular diagnosis. In this study we investigated the occurrence of EEHV and the efficiency of different techniques used to monitor EEHV infection in various samples and populations of Asian elephants. MATERIALS AND METHODS Blood and trunk swabs were collected from live elephants, while visceral organs (lung, digestive tract, spleen, lymph nodes, and kidney) were collected from dead elephants. EEHV was detected by polymerase chain reaction (PCR) in whole blood, trunk swabs, and visceral organs as samples, while elephant anti-EEHV immunoglobulin G (IgG) in serum was detected by enzyme-linked immunosorbent assay (ELISA). A total of 162 samples were analyzed in this study: 129 from healthy, 26 from dead, and 7 from sick elephants. RESULTS The present study showed that the overall incidence of EEHV was 40.1% (n=65/162). Approximately 46.2% (n=12/26) and 85.7% (n=6/7) of dead and sick elephants were positive for EEHV by PCR, respectively. All sick elephants that were young and affected by EEHV clinical disease tested negative for the IgG antibody ELISA, suggesting primary EEHV infection in this group. In addition, 2.3% (n=3/129) of subclinical infections were detected using PCR, and trunk swab samples showed slightly higher sensitivity (5.3%, n=2/38) to detect EEHV than whole blood (1.2%, n=1/84). As many as, 48.4% (n=44/91) of healthy elephants were EEHV seropositive (ELISA-positive), suggesting that many elephants in Thailand had previously been infected. Overall, 30% of dead wild elephants had been infected with EEHV (n=3/10). Moreover, statistical analysis revealed no significant differences in the EEHV detection rate between different age groups or sexes (p>0.05). CONCLUSION PCR is better than ELISA to detect EEHV active infection in dead/sick elephants and to monitor EEHV in young elephants. ELISA is suitable for detecting previous EEHV infection and carriers, particularly adults. Theoretically, we could use both PCR and ELISA to increase the sensitivity of testing, along with observing abnormal behavior to efficiently monitor this disease. Identification of EEHV carriers within elephant populations is important to prevent transmission to healthy individuals, especially young elephants with high mortality from EEHV. This is the first report from Thailand regarding EEHV infection in wild elephants, showing the importance of preventing disease transmission between captive and wild elephants.
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Affiliation(s)
- Phirom Prompiram
- The Monitoring and Surveillance Centre for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
- Laboratory of Veterinary Biomedicine, Faculty of Veterinary Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
| | - Witthawat Wiriyarat
- The Monitoring and Surveillance Centre for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
- Department of Preclinical Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
| | - Benjaporn Bhusri
- The Monitoring and Surveillance Centre for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
| | - Weena Paungpin
- The Monitoring and Surveillance Centre for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
| | - Waleemas Jairak
- Zoological Park Organization, 267 Pracharat 1 Road, Bangsue Bangkok 10800, Thailand
| | - Supaphen Sripiboon
- Department of Large Animal and Wildlife Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
| | - Tuempong Wongtawan
- Laboratory of Veterinary Biomedicine, Faculty of Veterinary Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
- Department of Preclinical Science, Mahidol University, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand
- Centre of Excellence for One Health, Akkhraratchakumari Veterinary College, Walailak University, Thai Buri, Tha Sala, Nakhon Si Thammarat 80160 Thailand
- Centre of Excellence Research for Melioidosis and other Microorganism, Walailak University, Thai Buri, Tha Sala, Nakhon Si Thammarat 80160 Thailand
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In vivo characterization of target cells for acute elephant endotheliotropic herpesvirus (EEHV) infection in Asian elephants (Elephas maximus). Sci Rep 2020; 10:11402. [PMID: 32647124 PMCID: PMC7347588 DOI: 10.1038/s41598-020-68413-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/24/2020] [Indexed: 12/16/2022] Open
Abstract
Elephant endotheliotropic herpesvirus-hemorrhagic disease (EEHV-HD) is a dangerous viral infectious disease in young Asian elephants. Despite hypotheses underlying pathogenesis of the disease, it is unclear which cell types the virus targets during acute or persistent infections. This study investigated the tissues and target cells permissive for EEHV infection and replication in vivo. Rabbit polyclonal antibodies against the non-structural proteins of EEHV, DNA polymerase (EEHV DNAPol), were generated and validated. These were used to examine EEHV infection and replication in various tissues of acute EEHV-HD cases and compared to an EEHV-negative control. The results indicated that viral antigens were distributed throughout the epithelia of the alimentary tract and salivary glands, endothelia and smooth muscle cells, and monocytic lineage cells of the EEHV-infected elephants. Moreover, EEHV DNAPol proteins were also found in the bone marrow cells of the EEHV1A-HD and EEHV1A/4-HD cases. This study demonstrated for the first time the target cells that favor in vivo EEHV replication during acute infection, providing a promising foundation for investigating EEHV propagation in vitro.
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Piewbang C, Kasantikul T, Pringproa K, Techangamsuwan S. Feline bocavirus-1 associated with outbreaks of hemorrhagic enteritis in household cats: potential first evidence of a pathological role, viral tropism and natural genetic recombination. Sci Rep 2019; 9:16367. [PMID: 31705016 PMCID: PMC6841677 DOI: 10.1038/s41598-019-52902-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/25/2019] [Indexed: 12/18/2022] Open
Abstract
Feline bocavirus-1 (FBoV-1) was identified in cats from different households with hemorrhagic enteritis during outbreaks of an unusual clinical presentation of feline panleukopenia virus (FPLV) in Thailand. Use of polymerase chain reaction revealed the presence of the FBoV-1 DNA in several tissues, suggesting hematogenous viremia, with the viral nucleic acid, detected by in situ hybridization (ISH), was localized in intestinal cells and vascular endothelium of intestinal mucosa and serosa, and in necrosis areas primarily in various lymph nodes while FPLV-immunohistochemical analysis revealed viral localization only in cryptal cells, neurons, and limited to leukocytes in the mesenteric lymph node. Full-length coding genome analysis of the Thai FBoV-1 strains isolated from moribund cats revealed three distinct strains with a high between-strain genetic diversity, while genetic recombination in one of the three FBoV-1 strains within the NS1 gene. This is the first report identifying natural genetic recombination of the FBoV-1 and describing the pathology and viral tropism of FBoV-1 infection in cats. Although the role of FBoV-1 associated with systemic infection of these cats remained undetermined, a contributory role of enteric infection of FBoV-1 is possible. Synergistic effects of dual infection with FPLV and FBoV-1 are hypothesized, suggesting more likely severe clinical presentations.
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Affiliation(s)
- Chutchai Piewbang
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Tanit Kasantikul
- Department of Preclinic and Applied Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Kidsadagon Pringproa
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
| | - Somporn Techangamsuwan
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand. .,Diagnosis and Monitoring of Animal Pathogens Research Unit, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
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Srivorakul S, Guntawang T, Kochagul V, Photichai K, Sittisak T, Janyamethakul T, Boonprasert K, Khammesri S, Langkaphin W, Punyapornwithaya V, Chuammitri P, Thitaram C, Pringproa K. Possible roles of monocytes/macrophages in response to elephant endotheliotropic herpesvirus (EEHV) infections in Asian elephants (Elephas maximus). PLoS One 2019; 14:e0222158. [PMID: 31491031 PMCID: PMC6730851 DOI: 10.1371/journal.pone.0222158] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 08/22/2019] [Indexed: 12/14/2022] Open
Abstract
Elephant endotheliotropic herpesvirus-hemorrhagic disease (EEHV-HD) is the primary cause of acute, highly fatal, hemorrhagic diseases in young Asian elephants. Although monocytopenia is frequently observed in EEHV-HD cases, the role monocytes play in EEHV-disease pathogenesis is unknown. This study seeks to explain the responses of monocytes/macrophages in the pathogenesis of EEHV-HD. Samples of blood, frozen tissues, and formalin-fixed, paraffin-embedded (FFPE) tissues from EEHV1A-HD, EEHV4-HD, co-infected EEHV1A and 4-HD, and EEHV-negative calves were analyzed. Peripheral blood mononuclear cells (PBMCs) from the persistent EEHV4-infected and EEHV-negative calves were also studied. The results showed increased infiltration of Iba-1-positive macrophages in the inflamed tissues of the internal organs of elephant calves with EEHV-HD. In addition, cellular apoptosis also increased in the tissues of elephants with EEHV-HD, especially in the PBMCs, compared to the EEHV-negative control. In the PBMCs of persistent EEHV4-infected elephants, cytokine mRNA expression was high, particularly up-regulation of TNF-α and IFN-γ. Moreover, viral particles were observed in the cytoplasm of the persistent EEHV4-infected elephant monocytes. Our study demonstrated for the first time that apoptosis of the PBMCs increased in cases of EEHV-HD. Furthermore, this study showed that monocytes may serve as a vehicle for viral dissemination during EEHV infection in Asian elephants.
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Affiliation(s)
- Saralee Srivorakul
- Veterinary Diagnostic Laboratory, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Thunyamas Guntawang
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Varankpicha Kochagul
- Veterinary Diagnostic Laboratory, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kornravee Photichai
- Veterinary Diagnostic Laboratory, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Tidaratt Sittisak
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | | | - Khajohnpat Boonprasert
- Center of Excellence in Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand
| | | | | | - Veerasak Punyapornwithaya
- Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Phongsakorn Chuammitri
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Chatchote Thitaram
- Center of Excellence in Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand.,Department of Companion Animals and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kidsadagon Pringproa
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand
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Boonprasert K, Punyapornwithaya V, Tankaew P, Angkawanish T, Sriphiboon S, Titharam C, Brown JL, Somgird C. Survival analysis of confirmed elephant endotheliotropic herpes virus cases in Thailand from 2006 - 2018. PLoS One 2019; 14:e0219288. [PMID: 31276571 PMCID: PMC6611605 DOI: 10.1371/journal.pone.0219288] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 06/20/2019] [Indexed: 11/19/2022] Open
Abstract
The elephant endotheliotropic herpesvirus (EEHV) has been a known cause of death of young elephants in Thailand for over a decade. In this study, we report on the demography, disease characteristics and mortality of 58 elephants with confirmed EEHV hemorrhagic disease between January 2006 and August 2018 using retrospective data subjected to survival analysis. Median age of EEHV presentation was 29 months, and the mortality rate was 68.97% with a median survival time of 36 h. Most EEHV cases occurred in the north of Thailand, the region where most of the country’s captive elephants reside. The hazard ratio analysis identified application of medical procedures and antiviral medications as being significant factors correlated to the risk of death. Our results indicate a need to focus EEHV monitoring efforts on young elephants and to follow current protocols that advise starting treatments before clinical signs appear.
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Affiliation(s)
| | - Veerasak Punyapornwithaya
- Center of Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand
- Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Pallop Tankaew
- Center of Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand
| | - Taweepoke Angkawanish
- Elephant Hospital, National Elephant Institute, Forest Industry Organization, Lampang, Thailand
| | - Supaphen Sriphiboon
- Department of Large Animal and Wildlife Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakornpathom, Thailand
| | - Chatchote Titharam
- Center of Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand
- Department of Companion Animal and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, Virginia, United State of America
| | - Chaleamchat Somgird
- Center of Elephant and Wildlife Research, Chiang Mai University, Chiang Mai, Thailand
- Department of Companion Animal and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- * E-mail:
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