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has been rarely reported but was recognised most commonly in the post-operative colonic volvulus patient by one author (Hassel 2017). None of the horses in the current study were affected by colonic volvulus, but this likely reflects the different population of horses seen at our hospital. Intestinal infarction can occur due to cardiogenic shock,
low flow states, or remote partial organic occlusion (Alschibaja and Morson 1977). Certainly, these mechanisms could explain the aetiologies in cases with enterocolitis and strangulating intestinal obstruction. Equine endotoxaemia occurs frequently in horses admitted with colic (King and Gerring 1988; Fessler et al. 1989; Steverink et al. 1994) and colitis (Larsen 1997). Experimental and clinical studies by Oikawa and Shiga (2002) and Oikawa et al. (2004) suggest that endotoxin-induced damage to the equine mesenteric arteries can result in a disturbance of intestinal blood flow and motility. The mesenteric circulation system has one of the body’slargest vascular beds and is likely to be predisposed to endotoxin- induced damage, disseminated intravascular coagulation and subsequent thrombosis. Thrombosis of vessels in the affected areas of intestine were frequently identified on histopathological examination in this study. However, the underlying causative mechanisms for NSII in this series remained undetermined in 47% of affected horses. In people, NSII is also seen secondary to atherosclerosis, pathology of mural vasculature, (vasculitis, collagen diseases, and intravascular coagulation), cardiac failure and arrhythmias, splanchnic vasoconstriction, and drug reactions (Alschibaja and Morson 1977). There was no history of recent medication in the horses with undetermined aetiologies, but it may be possible that some of these other mechanisms played a role. Atherosclerosis has been described in older horses with a predilection for the abdominal aorta and its branches (Gresham 1983). Intestinal infarction has also been described
in people secondary to arrhythmias and in particular atrial fibrillation. Atrial fibrillation is reported to be the most common type of exercising arrhythmia in horses (Schwarzwald 2003) but was not detected in any of our horses. In conclusion, NSII is a rare condition in horses in the UK.
Three different clinical presentations occur: acute colic; chronic/recurrent colic, depression, and inappetence; and diarrhoea, depression, and inappetence. Clinical deterioration associated with increasing pain, peritonitis, and cardiovascular compromise follow. The underlying cause of NSII is often undiagnosed, although some cases present secondary to colitis/typhlocolitis or strangulating intestinal lesions. The prognosis is poor. This series does not indicate re- emergence of NSII secondary to S. vulgaris in the UK as has been found in Denmark; however, further evaluation of cases using the S. vulgaris antibody ELISA test is warranted.
Authors' declaration of interests No conflicts of interest have been declared.
Ethical animal research
No declaration required for this clinical review. Owners gave consent for publication of images.
Source of funding No funding provided.
Acknowledgements
We thank colleagues at Bell Equine Veterinary Clinic. Histopathological examinations were undertaken at the Department of Veterinary Pathology, University of Bristol.
Authorship
J. Spanton collated the data. J. Spanton and T. Mair were equally involved in the study design, data analysis and interpretation, and preparation of the manuscript. C. Sherlock was involved in study design and preparation of the manuscript. D. Fews carried out all the histopathology and was involved in manuscript preparation. All authors gave final approval of the manuscript.
References
Alschibaja, T. and Morson, B.C. (1977) Ischaemic bowel disease. J. Clin. Path. 30, Suppl. 11, 68-77.
Duncan, J.L. and Pirie, H.M. (1975) The pathogenesis of single experimental infections with Strongylus vulgaris in foals. Res. Vet. Sci 18, 82-93.
Edwards, G.B., Kelly, D.F. and Proudman, C.J. (2000) Segmental eosinophilic colitis: a review of 22 cases. Equine Vet. J. 32, Suppl. 32, 86-93.
Enigk, K. (1951) Further studies on the biology of Strongylus vulgaris (Nematodes) in the host. Z. Tropenmed. Parasitol. 2, 523-535.
Fessler, J.F., Bottoms, G.D., Coppoc, G.L., Gimarc, S., Latshaw, H.S. and Noble, J.K. (1989) Plasma endotoxin concentrations in experimental and clinical equine subjects. Equine Vet. J., 21, Suppl. 7, 24-28.
Gerber, H., Chuit, P. and Pauli, B. (1971) Infarction of the small intestine in the horse. I. Clinical aspects. Schweiz. Arch. Tierheilkd. 113, 678- 684.
Gresham, G.A. (1983) Atherosclerosis in animals: comparative aspects. In: Arterial Pollution. NATO Advanced Science Institutes Series (Series A: Life Sciences). Eds: H. Peeters, G.A. Gresham and R. Paoletti. Vol 58. Springer, Boston, MA. pp 65-78.
Hackett, R.P. ( 2002) Non-strangulating infarction of the large colon. In: Manual of Equine Gastroenterology, Eds: T.S. Mair, T. Divers and N. Ducharme, Saunders, Edinburgh. p 293.
Hardy, J. (2008) Mural Infarction (Thromboembolic Colic). In: The Equine Acute Abdomen. Eds: N.A. White, J.N. Moore and T.S. Mair, Teton NewMedia, Jackson, WY. p 646.
Hassel, D.M. (2017) Postoperative complications. In: The Equine Acute Abdomen, 3rd edn., Eds: A.T. Blikslager, N.A. White and J.N. Moore, John Wiley & Sons, Hoboken, NJ. pp 624-638.
Herd, R.P. (1990) Equine parasite control – problems associated with intensive anthelmintic therapy. Equine Vet. Educ. 2, 41-47.
King, J.N. and Gerring, E.L. (1988) Detection of endotoxin in cases of equine colic. Vet. Rec. 123, 269–271.
Larsen, J. (1997) Acute colitis in adult horses. A review with emphasis on aetiology and pathogenesis. Vet. Q. 19, 72-80.
Love, S. (1992) The role of equine strongyles in the pathogenesis of colic and current options for prophylaxis. Equine Vet. J. 24, 5–9.
Mair, T.S. and Pearson, G.R. (1995) Multifocal non-strangulating intestinal infarction associated with larval cyathostomiasis in a pony. Equine Vet. J. 27, 154-155.
Martin-Cuervo, M., Gracia, L.A., Vietitez, V., Jim enez, J., Dur an, E. and
Ezquerra, L.J. (2013) Postsurgical segmental mesenteric ischemic thrombosis in a horse. Can. Vet. J. 54, 83-84.
Matthews, J.B. (2008) An update on cyathostomins: anthelmintic resistance and worm control. Equine Vet. Educ. 20, 552-560.
Nielsen, M.K., Vidyashankar, A.N., Olsen, S.N., Monrad, J. and Thamsborg, S.M. (2012) Strongylus vulgaris associated with usage
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