Setaria digitata was the main cause of equine neurological ataxia in Korea: 50 cases (2015-2016).
Abstract: This study was performed to examine and clarify the cause of hindlimb ataxia and neuropathy seen in the South Korean horse population. Fifty horses diagnosed with hindlimb ataxia and neuropathy were referred for this study. Neurological examination was performed on 47 horses while necropsy was performed in all 50 animals. The occurrence of neurological diseases increased rapidly in the summer and 47 out of 50 horses were referred after the end of July. The incidence of neurological diseases started from the southern part of Korea in July and proceeded northward in August and September. Although there was no correlation with age, Thoroughbred and Warmblood horses showed a higher incidence rate than Halla and Jeju horses. The incidence rate was 5 times higher in geldings than in mares and stallions. Of the 20 cases, 16 were diagnosed with eosinophilic meningoencephalomyelitis in 2015. The most common lesions observed in 2016 were parasitic meningoencephalomyelitis (10 cases, 33%) and eosinophilic meningomyelitis (7 cases, 23%). Histopathological analysis of the brain and spinal cord revealed nematodes of approximately 100-200 µm in diameter, microcavitation and infiltrates of eosinophils, and brown pigmented macrophage infiltrates. The nematodes were identified as Setaria digitata via DNA sequencing, performed subsequent to polymerase chain reaction using DNA isolated from formalin-fixed paraffin-embedded tissue sections of the spinal cord. These results show that aberrant migration of Setaria digitata larva in the brain and spinal cord was a major cause for neurological signs in horses.
Publication Date: 2021-03-29 PubMed ID: 33775991PubMed Central: PMC8182315DOI: 10.1292/jvms.20-0741Google Scholar: Lookup
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Summary
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The research investigates the main cause of hindlimb ataxia and neuropathy in horses found in South Korea, identifying the Setaria digitata as the primary culprit.
Methodology of the Study
- The investigation was based on 50 horses diagnosed with hindlimb ataxia and neuropathy in Korea between 2015 and 2016.
- Physical neurological exams were conducted on 47 of the horses, while all 50 went through a necropsy process.
- The pattern of occurrence of the neurological diseases, correlation with the breed, age and sex of the horses were all taken into account.
- The researchers studied the geographical progression of the disease starting from the southern part of Korea in July moving northward by September.
Findings of the Study
- It was noted that the occurrence of neurological diseases increased rapidly during the summer months with the majority of the cases referred after the end of July.
- The horse breeds which showed a higher incidence rate were Thoroughbred and Warmblood horses, compared to Halla and Jeju horses, with no significant correlation with the age factor.
- The incidence rate was found to be 5 times higher in geldings compared to mares and stallions.
- The most common diseases diagnosed included eosinophilic meningoencephalomyelitis (in 2015) and parasitic meningoencephalomyelitis and eosinophilic meningomyelitis (in 2016).
Role of Setaria digitata
- Upon histopathological analysis of the brain and spinal cord, the presence of nematodes was observed which after further research through DNA sequencing were identified as Setaria digitata.
- The nematodes were usually found to be approximately 100-200 µm in diameter and were seen to infiltrate the horses neuropathy with brown pigmented macrophage infiltrates and eosinophils.
- The study reveals that detrimental migration of the Setaria digitata larvae in the brain and spinal cord was a significant cause for the neurological issues in the horses.
Cite This Article
APA
Lee H, Hwang H, Ro Y, Kim JH, Lee K, Choi E, Bae Y, So B, Lee I.
(2021).
Setaria digitata was the main cause of equine neurological ataxia in Korea: 50 cases (2015-2016).
J Vet Med Sci, 83(5), 869-875.
https://doi.org/10.1292/jvms.20-0741 Publication
Researcher Affiliations
- Pathologic Diagnostic Laboratory, Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.
- Farm Animal Clinical Training and Research Center, Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang 25354, Korea.
- Pathologic Diagnostic Laboratory, Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.
- Pathologic Diagnostic Laboratory, Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.
- Pathologic Diagnostic Laboratory, Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.
- Pathologic Diagnostic Laboratory, Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.
- Pathologic Diagnostic Laboratory, Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.
- Farm Animal Clinical Training and Research Center, Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang 25354, Korea.
MeSH Terms
- Animals
- Ataxia / veterinary
- Encephalomyelitis / veterinary
- Female
- Horse Diseases / epidemiology
- Horses
- Male
- Republic of Korea / epidemiology
- Setaria Nematode
Conflict of Interest Statement
All authors do not have any potential conflicts-of-interest.
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Citations
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