Evaluation of recurrent laryngeal neuropathy in domestic and feral horse populations in Australia using histologic and immunohistochemical analysis: A pilot study.
Abstract: Little is known about potential differences in the left recurrent laryngeal nerve (Lrln) and left cricoarytenoideus dorsalis (LCAD) muscle between domestic and feral horse populations. If a difference exists, feral horses may provide a useful control population for research related to recurrent laryngeal neuropathy (RLN) and increase our understanding of potential population pressures influencing the incidence RLN. The objective of this study was to compare the Lrln and LCAD of domestic and feral horses using histological and immunohistochemical techniques (IHC). Sixteen horses, domestic (n = 8) and feral (n = 8), without clinical or ancillary examinations that were processed at an abattoir had the Lrln and LCAD muscle harvested immediately following death. Carcass weights were recorded. Subjective and morphometric histologic assessment were performed on Lrln sections. The LCAD was assessed for myosin heavy chain (fibre type proportion, diameter and grouping using IHC. Fibre-type grouping consistent with RLN was seen in both groups. Regenerating fibre clusters were more common in domestic compared to feral horses (p = 0.04). No other histologic differences occurred between groups. Muscle fibre typing demonstrated a lower mean percentage of type IIX fibres in the feral group compared to the domestic group (p = 0.03). There was no difference in type I or IIA proportions or mean diameter of any fibre type between the groups. The domestic population showed evidence of nerve regeneration suggesting RLN in this group, yet this was not supported by the higher proportion of type IIX muscle fibres compared to the feral population. Further evaluation to clarify the significance and wider occurrence of the differences is indicated.
© 2023 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.
Publication Date: 2023-06-15 PubMed ID: 37317987PubMed Central: PMC10357237DOI: 10.1002/vms3.1186Google 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 pilot study aims to examine potential differences in a specific nerve and muscle between domestic and feral horse populations, to understand if this could inform research on laryngeal neuropathy. It finds indications of nerve regeneration in domestic horses but sees no significant differences between the two populations in muscle fibre characteristics.
Objective of the Study
- The primary objective of this research was to compare the left recurrent laryngeal nerve (Lrln) and left cricoarytenoideus dorsalis (LCAD) muscle in domestic and feral horses. The researchers used histological (study of tissue microscopic structure) and immunohistochemical (IHC; employs antibodies to detect particular antigens in cells) techniques to observe any differences.
- The reason behind such investigation was the hypothesis that if there’s a difference between these two populations, feral horses may offer a beneficial control group for research related to recurrent laryngeal neuropathy (RLN), a condition that affects laryngeal functionality and results in abnormal movement or paralysis.
Methodology
- The researchers used sixteen horses for their study, equally split between domestic and feral horses. They took tissue samples from the mentioned nerve and muscle immediately after the horses were processed at an abattoir. They also noted the carcass weights.
- They performed subjective and morphometric assessments on Lrln sections and evaluated the LCAD muscle for the proportions, diameter and grouping of myosin heavy chain (a protein involved in muscle contraction) using IHC.
Key Findings
- The study found evidence of RLN in both domestic and feral horses, demonstrated by fibre-type grouping. Where regenerating fibre clusters were observed to be more common in domestic horses than in feral ones.
- The analysis did not reveal any other significant histologic differences between the two groups.
- An examination of muscle fibres revealed a lower average percentage of a specific fibre type (type IIX) in feral horses, compared to domestic ones. The proportion and mean diameter of other fibre types (type I and IIA) showed no notable differences between the two groups.
Total Implication
- While the study found some evidence of nerve regeneration that suggested the presence of RLN in the domestic horse population, this particular observation was not supported by the muscle fibre analysis—the proportion of type IIX muscle fibres was higher in the domestic group than in the feral group, a finding lacking obvious explanation.
- Hence, the authors acknowledged the need for further assessment to clarify the significance and broader presence of these differences.
Cite This Article
APA
Lean NE, Franklin SH, Steel C, Woolford L, White J, Ahern BJ.
(2023).
Evaluation of recurrent laryngeal neuropathy in domestic and feral horse populations in Australia using histologic and immunohistochemical analysis: A pilot study.
Vet Med Sci, 9(4), 1610-1617.
https://doi.org/10.1002/vms3.1186 Publication
Researcher Affiliations
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia.
- Equine Health and Performance Centre, University of Adelaide, Roseworthy, South Australia, Australia.
- U-Vet Equine Centre, University of Melbourne, Werribee, Victoria, Australia.
- Equine Health and Performance Centre, University of Adelaide, Roseworthy, South Australia, Australia.
- Office of the Pro Vice Chancellor Research and Innovation, Charles Sturt University, Wagga Wagga, New South Wales, Australia.
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia.
MeSH Terms
- Horses
- Animals
- Pilot Projects
- Horse Diseases / epidemiology
- Horse Diseases / pathology
- Laryngeal Muscles / innervation
- Laryngeal Muscles / pathology
- Muscles
- Australia
Conflict of Interest Statement
The authors declare no conflict of interest.
References
This article includes 30 references
- Adreani CM, Li ZB, Lehar M, Southwood LL, Habecker PL, Flint PW, Parente EJ. Myosin heavy chain composition in normal and atrophic equine laryngeal muscle.. Vet Pathol 2006 Nov;43(6):881-9.
- Barakzai SZ, Boden LA, Dixon PM. Race performance after laryngoplasty and ventriculocordectomy in National Hunt racehorses.. Vet Surg 2009 Dec;38(8):941-5.
- Boyko AR, Brooks SA, Behan-Braman A, Castelhano M, Corey E, Oliveira KC, Swinburne JE, Todhunter RJ, Zhang Z, Ainsworth DM, Robinson NE. Genomic analysis establishes correlation between growth and laryngeal neuropathy in Thoroughbreds.. BMC Genomics 2014 Apr 3;15:259.
- Cahill JI, Goulden BE. The pathogenesis of equine laryngeal hemiplegia--a review.. N Z Vet J 1987 Jun;35(6):82-90.
- nnCsurhes S, nParoz G, nMarkula A. Feral Horses: Invasive animal risk assessment. .
- Davidson E. Recurrent laryngeal neuropathy: Diagnosis, dynamic endoscopy. Advances in equine upper respiratory surgery pp. 9–15.
- Dixon PM, McGorum BC, Railton DI, Hawe C, Tremaine WH, Pickles K, McCann J. Clinical and endoscopic evidence of progression in 152 cases of equine recurrent laryngeal neuropathy (RLN).. Equine Vet J 2002 Jan;34(1):29-34.
- Draper ACE, Piercy RJ. Pathological classification of equine recurrent laryngeal neuropathy.. J Vet Intern Med 2018 Jul;32(4):1397-1409.
- Duncan ID, Hammang JP. Ultrastructural observations of organelle accumulation in the equine recurrent laryngeal nerve.. J Neurocytol 1987 Apr;16(2):269-80.
- Duncan ID, Reifenrath P, Jackson KF, Clayton M. Preferential denervation of the adductor muscles of the equine larynx. II: Nerve pathology.. Equine Vet J 1991 Mar;23(2):99-103.
- Galler S, Hilber K, Pette D. Stretch activation and myosin heavy chain isoforms of rat, rabbit and human skeletal muscle fibres.. J Muscle Res Cell Motil 1997 Aug;18(4):441-8.
- Goulden BE, Anderson LJ. Equine laryngeal hemiplegia, Part I: Physical characteristics of affected animals.. N Z Vet J 1981 Sep;29(9):151-4.
- Hahn CN, Mayhew IG. Examination of the laryngeal musculature and recurrent laryngeal nerves of zebra (Equus burchelli) for evidence of idiopathic laryngeal hemiplegia.. N Z Vet J 2000 Feb;48(1):20-3.
- Hahn CN, Matiasek K, Dixon PM, Molony V, Rodenacker K, Mayhew IG. Histological and ultrastructural evidence that recurrent laryngeal neuropathy is a bilateral mononeuropathy limited to recurrent laryngeal nerves.. Equine Vet J 2008 Nov;40(7):666-72.
- Hampson BA, de Laat MA, Mills PC, Pollitt CC. Distances travelled by feral horses in 'outback' Australia.. Equine Vet J Suppl 2010 Nov;(38):582-6.
- Hoh JF. Laryngeal muscle fibre types.. Acta Physiol Scand 2005 Feb;183(2):133-49.
- Katie J S, Padraic M D. Recurrent laryngeal neuropathy: Grading of recurrent laryngeal neuropathy. Advances in equine upper respiratory surgery pp. 1–8.
- Marks D, Mackay-Smith MP, Cushing LS, Leslie JA. Etiology and diagnosis of laryngeal hemiplegia in horses.. J Am Vet Med Assoc 1970 Aug 15;157(4):429-36.
- Matiasek K, Gais P, Rodenacker K, Jütting U, Tanck JJ, Schmahl W. Stereological characteristics of the equine accessory nerve.. Anat Histol Embryol 2008 Jun;37(3):205-13.
- McGivney CL, Gough KF, McGivney BA, Farries G, Hill EW, Katz LM. Exploratory factor analysis of signalment and conformational measurements in Thoroughbred horses with and without recurrent laryngeal neuropathy.. Equine Vet J 2019 Mar;51(2):179-184.
- Morris EA, Seeherman HJ. Evaluation of upper respiratory tract function during strenuous exercise in racehorses.. J Am Vet Med Assoc 1990 Feb 1;196(3):431-8.
- Rakesh V, Ducharme NG, Cheetham J, Datta AK, Pease AP. Implications of different degrees of arytenoid cartilage abduction on equine upper airway characteristics.. Equine Vet J 2008 Nov;40(7):629-35.
- Reiser PJ, Kline WO. Electrophoretic separation and quantitation of cardiac myosin heavy chain isoforms in eight mammalian species.. Am J Physiol 1998 Mar;274(3):H1048-53.
- Rhee HS, Steel CM, Derksen FJ, Robinson NE, Hoh JF. Immunohistochemical analysis of laryngeal muscles in normal horses and horses with subclinical recurrent laryngeal neuropathy.. J Histochem Cytochem 2009 Aug;57(8):787-800.
- Smith LR, Barton ER. SMASH - semi-automatic muscle analysis using segmentation of histology: a MATLAB application.. Skelet Muscle 2014;4:21.
- Steel C M, Walmsley E. Working towards a better understanding of laryngeal muscle changes in horses with recurrent laryngeal neuropathy using immunohistochemical techniques. .
- Sweeney CR, Maxson AD, Soma LR. Endoscopic findings in the upper respiratory tract of 678 Thoroughbred racehorses.. J Am Vet Med Assoc 1991 Mar 15;198(6):1037-8.
- Taylor NA, Wilkinson JG. Exercise-induced skeletal muscle growth. Hypertrophy or hyperplasia?. Sports Med 1986 May-Jun;3(3):190-200.
- Tulloch LK, Perkins JD, Piercy RJ. Multiple immunofluorescence labelling enables simultaneous identification of all mature fibre types in a single equine skeletal muscle cryosection.. Equine Vet J 2011 Jul;43(4):500-3.
- Zhong WW, Lucas CA, Kang LH, Hoh JF. Electrophoretic and immunochemical evidence showing that marsupial limb muscles express the same fast and slow myosin heavy chains as eutherians.. Electrophoresis 2001 Apr;22(6):1016-20.
Citations
This article has been cited 0 times.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
