Clinical and histopathological features in horses with neuroaxonal degeneration: 100 cases (2017-2021).
Abstract: Adult horses with proprioceptive ataxia and behavior changes that have histologic lesions consistent with neurodegenerative disease have been increasingly recognized. Objective: Describe the history, clinical findings and histopathologic features of horses presented to a referral institution with neuroaxonal degeneration. Methods: One hundred horses with a necropsy diagnosis of neuroaxonal degeneration compatible with neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM). Methods: Retrospective study of horses presented to the University of Pennsylvania, New Bolton Center, between 2017 and 2021 with a necropsy diagnosis of eNAD/EDM. Results: Affected horses had a median age of 8 years (range, 1-22), and the majority were Warmbloods (72). Sixty-eight horses had behavioral changes, and all 100 had proprioceptive ataxia (median grade, 2/5). Fifty-seven horses had abnormal findings on cervical vertebral radiographs, and 14 had myelographic findings consistent with compressive myelopathy. No antemortem diagnostic test results were consistently associated with necropsy diagnosis of neurodegenerative disease. All 100 horses had degenerative lesions characteristic of eNAD in the brainstem gray matter, and 24 had concurrent degenerative features of EDM in the spinal cord white matter. Conclusions: Clinical and histopathologic findings in this large group of horses with neurodegenerative disease were most consistent with eNAD/EDM, but with a different signalment and clinical presentation from earlier descriptions. The increasing occurrence of neurodegenerative disease in horses and the safety risk posed emphasize the importance of focused research in affected horses.
© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
Publication Date: 2023-12-14 PubMed ID: 38095342PubMed Central: PMC10800219DOI: 10.1111/jvim.16969Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research examines the clinical, historical, and histopathological features of horses diagnosed with neuroaxonal degeneration. The study is based on 100 cases handled by the University of Pennsylvania, New Bolton Center, between 2017 and 2021. Given the increasing occurrence of this neurodegenerative disease in horses and the safety risks it poses, the study underscores the significance of concentrated research in this field.
Objective and Methods
- The main objective of the study was to document the history, clinical findings, and histopathological features of horses diagnosed with neuroaxonal degeneration, often related to equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM).
- The method used was retrospective, looking back at horses that were presented to the given university center with a necropsy diagnosis of eNAD/EDM over a period of four years.
Results
- The findings reveal that the majority of horses affected were Warmbloods (72 out of 100), with a median age of 8 years.
- Behavioural changes were observed in sixty-eight of the horses, while all featured proprioceptive ataxia (a lack of self-movement and body positioning).
- Fifty-seven horses displayed abnormal findings in their cervical vertebral radiographs, while fourteen presented with signs of compressive myelopathy (damage to the spinal cord).
- No premortem diagnostic tests were consistently associated with a necropsy diagnosis of the neurodegenerative disease.
- The histopathology showed that all the horses had degenerative lesions typical of eNAD in the brainstem gray matter. Concurrently, 24 had degenerative features of EDM in the spinal cord white matter.
Conclusions
- The study concludes that the clinical and histopathological findings in these horses were most consistent with eNAD/EDM. However, the clinical presentation differed from the earlier descriptions.
- The research highlights the growing incidence of neurodegenerative disease in horses, pointing out the safety risks these present. It hence emphasizes the importance of conducting focused research on affected horses to get a better understanding and develop useful interventions.
Cite This Article
APA
Brown KA, Bender SJ, Johnson AL.
(2023).
Clinical and histopathological features in horses with neuroaxonal degeneration: 100 cases (2017-2021).
J Vet Intern Med, 38(1), 431-439.
https://doi.org/10.1111/jvim.16969 Publication
Researcher Affiliations
- Department of Clinical Studies-New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania, USA.
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA.
- Department of Clinical Studies-New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania, USA.
MeSH Terms
- Horses
- Animals
- Neurodegenerative Diseases / veterinary
- Retrospective Studies
- Neuroaxonal Dystrophies / veterinary
- Spinal Cord Compression / veterinary
- Ataxia / veterinary
- Horse Diseases / diagnosis
Conflict of Interest Statement
Dr. Johnson has spoken at educational meetings in addition to serving as an expert witness in a trial involving a horse with neurodegenerative disease. However, she has no financial investment in the topics addressed in this manuscript. Histologic specimens were evaluated separately by Dr. Bender to minimize risk of bias.
References
This article includes 27 references
- Mayhew IG, DeLahunta A, Whitlock RH. Equine degenerative myeloencephalopathy.. J Am Vet Med Assoc 1977;170(2):195‐201.
- Beech J. Neuroaxonal dystrophy of the accessory cuneate nucleus in horses.. Vet Pathol 1984;21(4):384‐393.
- Aleman M, Finno CJ, Higgins RJ. Evaluation of epidemiological, clinical, and pathological features of neuroaxonal dystrophy in quarter horses.. J Am Vet Med Assoc 2011;239(6):823‐833.
- Summers BA, DeLahunta A, Cummings JF. Veterinary Neuropathology.. 1st ed. Baltimore: Mosby; 1995:315.
- Adams AP, Collatos C, Fuentealba C, Illanes O, Blanchard R. Neuroaxonal dystrophy in a two‐year‐old quarter horse filly.. Can Vet J 1996;37(1):43‐44.
- Mayhew LG, DeLahunta A, Whitlock RH. Spinal cord disease in the horse.. Cornell Vet 1978;68(6):1‐207.
- Craig A, Blythe L, Lassen ED, Rowe KE, Barrington R, Slizeski M. Variations of serum vitamin E, cholesterol, and total serum lipid concentrations in horses during a 72‐hour period.. Am J Vet Res 1989;50(9):1527‐1531.
- Finno CJ, Johnson AL. Equine neuroaxonal dystrophy and degenerative myeloencephalopathy.. Vet Clin Equine 2022;38(2):213‐224.
- Reed SM. Neurologic exam.. J Equine Vet Sci 2003;11:484‐492.
- Johnson AL, Johnstone LK, Stefanovski D. Cerebrospinal fluid Lyme multiplex assay results are not diagnostic in horses with neuroborreliosis.. J Vet Intern Med 2018;32(2):832‐838.
- Edwards LA, Donnelly CG, Reed SM. Serum and cerebrospinal fluid phosphorylated neurofilament heavy protein concentrations in equine neurodegenerative diseases.. Equine Vet J 2022;54(2):290‐298.
- Dill SG, Correa M, Erb HN, DeLahunta A, Kallfelz FA, Waldron C. Factors associated with the development of equine degenerative myeloencephalopathy.. Am J Vet Res 1990;51(8):1300‐1305.
- Blythe L, Craig A, Lassen ED, Rowe KE, Appell LH. Serially determined plasma alpha‐tocopherol concentrations and results of the oral vitamin E absorption test in clinically normal horses and in horses with degenerative myeloencephalopathy.. Am J Vet Res 1991;52(6):908‐911.
- Brosnahan M, Holbrook TC, Ritchey J. Neuroaxonal dystrophy associated with cerebellar dysfunction in a 5‐month‐old pony of the Americas colt.. J Vet Intern Med 2009;23(6):1303‐1306.
- Finno CJ, Higgins RJ, Aleman M. Equine degenerative myeloencephalopathy in Lusitano horses.. J Vet Intern Med 2011;25(6):1439‐1446.
- Desrumaux CM, Mansuy M, Lemaire S. Brain vitamin E deficiency during development is associated with increased glutamate levels and anxiety in adult mice.. Front Behav Neurosci 2018;12:1‐7.
- Zhong M, Gu R, Zhu S. Prevalence and risk factors for minor hallucinations in patients with Parkinson's disease.. Behav Neurol 2021;2021:1‐10.
- Barrett MJ, Smolkin ME, Flanigan JL, Shah BB, Harrison MB, Sperling SA. Characteristics, correlates, and assessment of psychosis in Parkinson disease without dementia.. Park Relat Disord 2017;43:56‐60.
- Ehgoetz Martens KA, Lewis SJG. Pathology of behavior in PD: what is known and what is not?. J Neurol Sci 2017;374:9‐16.
- Finno CJ, Famula T, Aleman M, Higgins RJ, Madigan JE, Bannasch DL. Pedigree analysis and exclusion of alpha‐tocopherol transfer protein (TTPA) as a candidate gene for neuroaxonal dystrophy in the American quarter horse.. J Vet Intern Med 2013;27:177‐185.
- Hales EN, Habib H, Favro G. Increased α‐tocopherol metabolism in horses with equine neuroaxonal dystrophy.. J Vet Intern Med 2021;35(5):2473‐2485.
- Mullen KR, Rivera BN, Tidwell LG, Ivanek R, Anderson KA, Ainsworth DM. Environmental surveillance and adverse neonatal health outcomes in foals born near unconventional natural gas development activity.. Sci Total Environ 2020;731:1‐13.
- Jahns H, Callanan JJ, McElroy MC, Sammin DJ, Bassett HF. Age‐related and non‐age‐related changes in 100 surveyed horse brains.. Vet Pathol 2006;43(5):740‐750.
- Peng C, Trojanowski JQ, Lee VMY. Protein transmission in neurodegenerative disease.. Nat Rev Neurol 2020;16(4):199‐212.
- Story MR, Nout‐Lomas YS, Aboellail TA. Dangerous behavior and intractable axial skeletal pain in performance horses: a possible role for ganglioneuritis (14 cases; 2014‐2019).. Front Vet Sci 2021;8:1‐11.
- Finno CJ, Valburg SJ. A comparative review of vitamin E and associated equine disorders.. J Vet Intern Med 2012;26:1251‐1266.
- Roneus BO, Hakkarainen RVJ, Lindholm CA, Tyopponen JT. Vitamin E requirements of adult standardbred horses evaluated by tissue depletion and repletion.. Equine Vet J 1986;18(1):50‐58.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
