The pathogenesis of single experimental infections with Strongylus vulgaris in foals.
- Journal Article
Summary
This study examines the development and impact of single experimental infections caused by Strongylus vulgaris, a prominent internal parasite in horses, focusing on worm-free foals. The primary clinical signs in infected foals include fever, loss of appetite, dullness, and abdominal pain within the first three weeks of infection. The results show an increase in certain white blood cell counts and high serum globulin levels, indicating an immune response. Post-infection, the disease manifests through lesions, inflammation, and arterial thrombosis. Although arterial lesions appeared to have healed nine months post-infection, the arterial wall still showed signs of fibrosis and the presence of haemosiderin.
Understanding the infection process
- The article focuses on how the parasitic nematode, Strongylus vulgaris, causes infections in pony foals, highlighting the progression of infection and the related pathology.
- Once the foals are infected, the first clinical signs—fever, loss of appetite, dullness, and abdominal pain—become apparent within the first three weeks.
- During the initial two weeks, the infection leads to lesions primarily confined to the intestine and the final branches of the intestinal arteries, accompanied by arteritis and a noticeable inflammatory reaction.
Impact on the intestinal arteries
- Three weeks post-infection, a major symptom is the significant thrombosis of the anterior mesenteric artery or one of its large branches. These affected arteries demonstrated significant intimal thickening and infiltration of various immune cells, indicating an immune response to the infection.
- The lesions seen between one and four months post-infection primarily consisted of fibrous thickening of the arterial wall and thrombosis. This appearance is correlated with the presence of developing fourth-stage larvae of the nematode.
Long-term effects and healing
- Even four months after infection, the arterial lesions remained prominent and microscopically, there was fibrosis (formation of excess fibrous connective tissue) of the affected arterial wall along with widespread disruption of the intima (the innermost layer of the artery).
- No signs of the disease were seen nine months after infection, but microscopic examination revealed fibrosis of the intima, indicating that the damage caused by the infection was permanent.
Clinical pathology findings
- The blood examination of the infected foals showed increased numbers of polymorphonuclear leukocytes and eosinophils, indices of an immune response.
- The levels of serum globulin, a group of proteins involved in the immune response, were also increased in the infected foals, forming an integral part of the body’s defense mechanism against the parasite.
Cite This Article
Publication
Researcher Affiliations
MeSH Terms
- Animals
- Arteries / pathology
- Arteritis / veterinary
- Blood Proteins / analysis
- Body Temperature
- Cecum / pathology
- Erythrocyte Count
- Hematocrit
- Hemoglobins
- Horses
- Ileum / pathology
- Intestines / blood supply
- Leukocyte Count
- Mesenteric Arteries / pathology
- Mesenteric Vascular Occlusion / veterinary
- Rectum
- Strongyle Infections, Equine / blood
- Strongyle Infections, Equine / pathology
- Thrombosis / veterinary
Citations
This article has been cited 23 times.- Osterman-Lind E, Hedberg Alm Y, Hassler H, Wilderoth H, Thorolfson H, Tydén E. Evaluation of Strategies to Reduce Equine Strongyle Infective Larvae on Pasture and Study of Larval Migration and Overwintering in a Nordic Climate. Animals (Basel) 2022 Nov 10;12(22).
- Jürgenschellert L, Krücken J, Bousquet E, Bartz J, Heyer N, Nielsen MK, von Samson-Himmelstjerna G. Occurrence of Strongylid Nematode Parasites on Horse Farms in Berlin and Brandenburg, Germany, With High Seroprevalence of Strongylus vulgaris Infection. Front Vet Sci 2022;9:892920.
- Honoré ML, Pihl TH, Busk-Anderson TM, Flintrup LL, Nielsen LN. Investigation of two different human d-dimer assays in the horse. BMC Vet Res 2022 Jun 15;18(1):227.
- Hedberg-Alm Y, Tydén E, Tamminen LM, Lindström L, Anlén K, Svensson M, Riihimäki M. Clinical features and treatment response to differentiate idiopathic peritonitis from non-strangulating intestinal infarction of the pelvic flexure associated with Strongylus vulgaris infection in the horse. BMC Vet Res 2022 Apr 23;18(1):149.
- Tombak KJ, Hansen CB, Kinsella JM, Pansu J, Pringle RM, Rubenstein DI. The gastrointestinal nematodes of plains and Grevy's zebras: Phylogenetic relationships and host specificity. Int J Parasitol Parasites Wildl 2021 Dec;16:228-235.
- Elmeligy E, Abdelbaset A, Elsayed HK, Bayomi SA, Hafez A, Abu-Seida AM, El-Khabaz KAS, Hassan D, Ghandour RA, Khalphallah A. Oxidative stress in Strongylus spp. infected donkeys treated with piperazine citrate versus doramectin. Open Vet J 2021 Apr-Jun;11(2):238-250.
- Tydén E, Enemark HL, Franko MA, Höglund J, Osterman-Lind E. Prevalence of Strongylus vulgaris in horses after ten years of prescription usage of anthelmintics in Sweden. Vet Parasitol X 2019 Nov;2:100013.
- Hedberg-Alm Y, Penell J, Riihimäki M, Osterman-Lind E, Nielsen MK, Tydén E. Parasite Occurrence and Parasite Management in Swedish Horses Presenting with Gastrointestinal Disease-A Case-Control Study. Animals (Basel) 2020 Apr 7;10(4).
- Nielsen MK, Scare J, Gravatte HS, Bellaw JL, Prado JC, Reinemeyer CR. Changes in Serum Strongylus Vulgaris-Specific Antibody Concentrations in Response to Anthelmintic Treatment of Experimentally Infected Foals. Front Vet Sci 2015;2:17.
- Borji H, Moosavi Z, Ahmadi F. Cranial Mesenteric Arterial Obstruction Due To Strongylus vulgaris Larvae in a Donkey (Equus asinus). Iran J Parasitol 2014 Sep;9(3):441-4.
- Nielsen MK, Vidyashankar AN, Bellaw J, Gravatte HS, Cao X, Rubinson EF, Reinemeyer CR. Serum Strongylus vulgaris-specific antibody responses to anthelmintic treatment in naturally infected horses. Parasitol Res 2015 Feb;114(2):445-51.
- Andersen UV, Howe DK, Dangoudoubiyam S, Toft N, Reinemeyer CR, Lyons ET, Olsen SN, Monrad J, Nejsum P, Nielsen MK. SvSXP: a Strongylus vulgaris antigen with potential for prepatent diagnosis. Parasit Vectors 2013 Apr 4;6:84.
- Hubert JD, Seahorn TL, Klei TR, Hosgood G, Horohov DW, Moore RM. Clinical signs and hematologic, cytokine, and plasma nitric oxide alterations in response to Strongylus vulgaris infection in helminth-naïve ponies. Can J Vet Res 2004 Jul;68(3):193-200.
- DeLay J, Peregrine AS, Parsons DA. Verminous arteritis in a 3-month-old thoroughbred foal. Can Vet J 2001 Apr;42(4):289-91.
- Wynne E, Slocombe JO, Wilkie BN. Antigenic analyses of tissues and excretory and secretory products from Strongylus vulgaris. Can J Comp Med 1981 Jul;45(3):259-65.
- McCraw BM, Slocombe JO. Strongylus equinus: development and pathological effects in the equine host. Can J Comp Med 1985 Oct;49(4):372-83.
- Palmer JE. Gastrointestinal diseases of foals. Vet Clin North Am Equine Pract 1985 Apr;1(1):151-68.
- Slocombe JO, Rendano VT, Owen RR, Pennock PW, McCraw BM. Arteriography in ponies with Strongylus vulgaris arteritis. Can J Comp Med 1977 Apr;41(2):137-45.
- McCraw BM, Slocombe JO. Strongylus vulgaris in the horse: a review. Can Vet J 1976 Jun;17(6):150-7.
- Lu Y, Ru P, Qin S, Zhang Y, Fu E, Cai M, Tuohuti N, Wu H, Zhang Y, Zhang Y. Epidemiological Patterns of Gastrointestinal Parasitic Infections in Equine Populations from Urumqi and Ili, Xinjiang, China. Vet Sci 2025 Jul 6;12(7).
- Stahel L, Bigler NA, Grimm F, Schnyder M, Oehm AW. Case report: The gastrointestinal nematode Strongylus vulgaris as a cause of hoof abscess in a donkey. BMC Vet Res 2025 Jul 10;21(1):454.
- Baghdadi HBA, Abdelsalam M, Attia MM. Diagnostic innovations in Equine Parasitology: a Nanogold-ELISA for sensitive serodiagnosis of migratory strongylus vulgaris larvae infections. BMC Vet Res 2024 Dec 27;20(1):579.
- Kuzmina TA, Königová A, Burcáková L, Babjak M, Syrota Y. Strongylids of Domestic Horses in Eastern Slovakia: Species Diversity and Evaluation of Particular Factors Affecting Strongylid Communities. Acta Parasitol 2024 Jun;69(2):1284-1294.