Onchocerca sp. in an imported Zangersheide gelding causing suspensory ligament desmitis.
Abstract: A 5-year-old imported Zangersheide gelding was evaluated for SC swellings over both forelimbs and lameness localized to the distal metacarpus. Ultrasound examination of the SC masses was compatible with verminous granulomas. Linear hyperechoic foci were present within the suspensory ligament branches of both forelimbs, suggestive of ligamentous parasitic infiltrates. A diagnosis of onchocerciasis was confirmed on biopsy of a SC mass. The gelding was treated with ivermectin and a tapering course of PO dexamethasone but was eventually euthanized. Necropsy confirmed the presence of SC eosinophilic granulomas and degenerative suspensory ligament desmitis, both with intralesional nematodes. Given the location and appearance of the nematode, a diagnosis of Onchocerca sp., most likely O. reticulata, was made. Onchocerciasis should be included as a differential diagnosis for multifocal suspensory ligament desmitis with these sonographic characteristics when paired with SC masses in imported European Warmbloods.
© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
Publication Date: 2023-02-23 PubMed ID: 36821075PubMed Central: PMC10061162DOI: 10.1111/jvim.16653Google Scholar: Lookup
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Summary
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This research focuses on a case of a five-year-old gelding horse imported from Zangersheide that was diagnosed with onchocerciasis, an infection by a certain type of parasitic worm, after being presented with swellings and lameness. Despite treatment, the horse was eventually euthanized. The infection was confirmed on postmortem examination, which also revealed indications of this hors’ breed being at risk from such infections.
Background
- The study revolves around the case of a 5-year-old imported Zangersheide gelding that was evaluated due to swellings on both its forelimbs and lameness localized at the distal metacarpus – the part of the limb corresponding to the human wrist.
- The study discusses onchocerciasis – an infection caused by Onchocerca sp., a type of parasitic worm, which in this case was most possibly of the species O. reticulata.
Diagnostic Procedures
- Ultrasound examination was performed on the swellings that the horse presented, and the results indicated the possibility of verminous granulomas – masses caused by inflammatory reactions to the presence of parasites.
- Further, the ultrasound also showed hyperechoic foci – regions where more sound waves reflect back to the transducer, indicating some kind of abnormality – within the suspensory ligament branches of both forelimbs. This suggested the presence of parasitic infiltrates in the ligaments.
- A biopsy on one of the swellings or SC masses confirmed the diagnosis of onchocerciasis.
Treatment and Outcome
- The gelding was treated with ivermectin – a medication commonly given to control parasitic infestations – and a course of PO (per os, or oral) dexamethasone, which is a type of steroid.
- However, the horse had to be euthanized eventually. A necropsy – postmortem examination – confirmed the presence of eosinophilic granulomas, which are inflammatory lesions, in the superficial cervical (SC) region and degenerative suspensory ligament desmitis with intralesional nematodes, indicating damage and inflammation of the ligament due to the presence of parasites.
Implications
- The study points out that Onchocerciasis could potentially be a differential diagnosis for multifocal suspensory ligament desmitis when paired with SC masses, particularly in imported European Warmbloods.
- It reiterates the need for thorough examination and treatment for horses showing signs of lameness, swellings, and ultrasound results indicative of possible parasitic infiltrates.
Cite This Article
APA
Brown KA, Johnson AL, Bender SJ, Nolan TJ, Pfisterer B, Slack J, Willis E, Rule EK.
(2023).
Onchocerca sp. in an imported Zangersheide gelding causing suspensory ligament desmitis.
J Vet Intern Med, 37(2), 735-739.
https://doi.org/10.1111/jvim.16653 Publication
Researcher Affiliations
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
- Department of Pathobiology, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
- Department of Pathobiology, Ryan Veterinary Hospital, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania 19104, USA.
- Department of Pathobiology, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
- Department of Pathobiology, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA.
MeSH Terms
- Animals
- Horses
- Male
- Onchocerca
- Onchocerciasis / diagnosis
- Onchocerciasis / parasitology
- Onchocerciasis / pathology
- Onchocerciasis / veterinary
- Ligaments / pathology
- Arthritis / veterinary
- Muscular Diseases / pathology
- Muscular Diseases / veterinary
- Horse Diseases / diagnostic imaging
- Horse Diseases / drug therapy
Conflict of Interest Statement
Authors declare no conflict of interest.
References
This article includes 19 references
- Sellon DC. Equine infectious anemia.. Vet Clin North Am Equine Pract 1993;9(2):321‐336.
- Wise LN, Kappmeyer LS, Mealey RH, Knowles DP. Review of equine piroplasmosis.. J Vet Intern Med 2013;27(6):1334‐1346.
- Luddy S, Kutzler MA. Contagious equine metritis in the United States: a review of the 2008 outbreak.. J Equine Vet Sci 2010;30(8):393‐400.
- Enk CD. Onchocerciasis – river blindness.. Clin Dermatol 2006;24:176‐180.
- Cambra‐Pellejà M, Gandasegui J, Balaña‐Fouce R, Muñoz J, Martínez‐Valladares M. Zoonotic implications of onchocerca species on human health.. Pathogens 2020;9(9):1‐17.
- Lloyd S, Soulsby EJ. Survey for infection with Onchocerca cervicalis in in horses in eastern United States.. Am J Vet Res 1978;39(12):1962‐1963.
- Moran CT, James ER. Equine ocular pathology ascribed to Onchocerca cervicalis infection: a re‐examination.. Trop Med Parasitol 1987;38(4):287‐288.
- Polley L. Onchocerca in horses from Western Canada and northwestern United States: an abattoir survey of the prevalence of infection.. Can Vet J 1984;25:128‐129.
- El Sammani SE, Hussein HS. Onchocerca raillieti: adult location and skin distribution of the microfilaria in Sudanese donkeys.. J Helminthol 1983;57(4):355‐360.
- Paraschou G, Adako GM, Priestnall SL, Burden FA. Suspensory ligament desmitis caused by Onchocerca sp. in three donkeys.. Vet Pathol 2021;58(2):401‐404.
- Berdnik OA. Revision on the validity of Onchocerca cervicalis and O. reticulata .. Uzbekskii Biologicheskii Zhurnal 1958;5:59‐64.
- Taylor HR, Greene BM. The status of ivermectin in the treatment of human onchocerciasis.. Am J Trop Med 1989;41(4):460‐466.
- Scott D, Miller W. Parasitic diseases.. In: Scott D, Miller W, eds. Equine dermatology. 2nd ed. Maryland Heights, MO: Saunders; 2011:212‐250.
- Wesołowska M, Zając‐Pytrus H, Masny A. Onchocerca jakutensis ocular infection in Poland: a new vector‐borne human health risk?. Parasit Vectors 2020;13(1):1‐4.
- Otranto D, Giannelli A, Trumble NS. Clinical case presentation and a review of the literature of canine onchocercosis by Onchocerca lupi in the United States.. Parasit Vectors 2015;8(1):1‐8.
- Lyons ET, Drudge JH, Tolliver SC. Verification of ineffectual activity of ivermectin against adult Onchocerca spp. in the ligamentum nuchae in horses.. Am J Vet Res 1988;49(7):983‐985.
- Taylor MJ, Hoerauf A, Townson S, Slatko BE, Ward SA. Anti‐Wolbachia drug discovery and development: safe macrofilaricides for onchocerciasis and lymphatic filariasis.. Parasitology 2014;141(1):119‐127.
- Hotterbeekx A, Namale Ssonko V, Oyet W, Lakwo T, Idro R. Neurological manifestations in Onchocerca volvulus infection: a review.. Brain Res Bull 2018;2019(145):39‐44.
- Hestvik G, Ekman S, Lindberg R. Onchocercosis of an intervertebral joint capsule causing cervical vertebral stenotic myelopathy in a horse.. J Vet Diagnostic Invest 2006;18(3):307‐310.
Citations
This article has been cited 1 times.- Moore CO, Robveille C, Qurollo B, Breitschwerdt EB. Detection of Dirofilaria repens and Mansonella llewellyni in the United States by Wolbachia Surveillance. Transbound Emerg Dis 2025;2025:2778610.
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