Topic:Intestinal Pathology
Intestinal pathology in horses encompasses a range of disorders affecting the structure and function of the equine gastrointestinal tract. These conditions can include inflammatory, infectious, obstructive, and degenerative diseases that impact the intestines. Common intestinal pathologies in horses include colitis, enteritis, and intestinal torsion, each with distinct histopathological features and clinical presentations. Diagnostic approaches often involve clinical examination, imaging techniques, and histological analysis to identify the underlying pathology. This page aggregates peer-reviewed research studies and scholarly articles that explore the etiology, diagnosis, and management of intestinal pathologies in equine medicine.
Changes in equine intestinal stem/progenitor cell number at resection margins in cases of small intestinal strangulation. Intestinal epithelial stem cells (ISC) are responsible for epithelial regeneration and are critical to the intestine's ability to regain barrier function following injury. Evaluating ISC biomarker expression in cases of small intestinal strangulation (SIS) may provide insight into clinical progression. Objective: Intestinal resection margins from cases of SIS were evaluated to determine if (1) evidence of injury could be identified using histomorphometry, (2) ISC biomarker expression was decreased in the proximal resection margin compared to control and distal resection margin, and (3) the ISC...
Use of a new device for inversion of the necrotic ileal stump in the caecum in four horses. In jejunocaecal anastomosis leaving a necrotic ileal stump has been implicated in complications and poor outcomes. Elective inversion of the necrotic stump using a nasogastric tube has been previously described, although this procedure can be cumbersome and can cause caecocolic orifice occlusion. Objective: To describe the use of a new device for elective inversion of necrotic ileal stumps. Methods: Case report. Methods: Details of the four horses that underwent intestinal resection and anastomosis with elective inversion of the ileal stump were retrieved from their medical records. For each c...
The Role of Yeast Saccharomyces cerevisiae in Supporting Gut Health in Horses: An Updated Review on Its Effects on Digestibility and Intestinal and Fecal Microbiota. To support the overall health of horses, it is essential to maintain an optimal gut health (GH) status, which encompasses several physiological and functional aspects, including the balance and functionality of intestinal microbial populations and, accordingly, the effective digestion and absorption of nutrients. Numerous biotic and abiotic stressors can lead to an imbalance of GH, such as the quality of forages and the composition of diet, e.g., the inclusion of high energy-dense feeds to meet the energy requirements of performance horses. To support the digestive function and the intestinal ...
Adaptive mechanisms in no flow vs. low flow ischemia in equine jejunum epithelium: Different paths to the same destination. Intestinal ischemia reperfusion injury (IRI) is a frequent complication of equine colic. Several mechanisms may be involved in adaptation of the intestinal epithelium to IRI and might infer therapeutic potential, including hypoxia-inducible factor (HIF) 1α, AMP-activated protein kinase (AMPK), nuclear factor-erythroid 2-related factor 2 (NRF2), and induction of autophagy. However, the mechanisms supporting adaptation and thus cellular survival are not completely understood yet. We investigated the activation of specific adaptation mechanisms in both no and low flow ischemia and reperfusion si...
Low Flow versus No Flow: Ischaemia Reperfusion Injury Following Different Experimental Models in the Equine Small Intestine. In experimental studies investigating strangulating intestinal lesions in horses, different ischaemia models have been used with diverging results. Therefore, the aim was to comparatively describe ischaemia reperfusion injury (IRI) in a low flow (LF) and no flow (NF) model. Under general anaesthesia, 120 min of jejunal ischaemia followed by 120 min of reperfusion was induced in 14 warmbloods. During ischaemia, blood flow was reduced by 80% (LF, n = 7) or by 100% (NF, n = 7). Intestinal blood flow and oxygen saturation were measured by Laser Doppler fluxmetry and spectrophotometry. Clinical, hi...
Umbilical Cord Herniation With Small Intestinal Evisceration in Two Thoroughbred Neonates. This report describes two cases of spontaneous small intestinal evisceration via normally inserted umbilical stumps, without abdominal wall trauma. Both cases occurred immediately following uneventful parturition. The authors believe that these represent cases of umbilical cord herniation. This is a well-recognised condition in humans, but has not been previously described in equines. One foal died before veterinary intervention. The second foal underwent a jejunal resection with end-to-end anastomosis and survived to successfully race. This report describes a previously unrecognised condition...
Interpreting abdominal fluid in colic horses: Understanding and applying peritoneal fluid evidence. Interpreting changes in peritoneal fluid helps clinicians manage colic and other diseases in horses. During abdominal problems in the horse, abdominal fluid characteristics such as color, turbidity, total nucleated and red blood cell counts, cytology, total protein, and l-lactate change in predictable ways, helping the clinician characterize the disease. Methods: Normal abdominal fluid in horses is odorless, clear to light yellow in color, and transparent. Peritoneal fluid becomes more turbid with increasing levels of protein, number of WBCs or RBCs, or with gross contamination following intes...
Age-Dependent Intestinal Repair: Implications for Foals with Severe Colic. Colic is a leading cause of death in horses, with the most fatal form being strangulating obstruction which directly damages the intestinal barrier. Following surgical intervention, it is imperative that the intestinal barrier rapidly repairs to prevent translocation of gut bacteria and their products and ensure survival of the patient. Age-related disparities in survival have been noted in many species, including horses, humans, and pigs, with younger patients suffering poorer clinical outcomes. Maintenance and repair of the intestinal barrier is regulated by a complex mucosal microenvironmen...
Evaluation of Inner Exposure of Horses to Zearalenone (ZEN), Deoxynivalenol (DON) and Their Metabolites in Relation to Colic and Health-Related Clinical-Chemical Traits. Mycotoxin contaminated feed has been associated with colic of horses caused by intestinal disorders. Whether such disease conditions alter the intestinal toxin metabolism and transfer across a compromised mucosal barrier is unknown. A screening approach was used to relate blood residue levels of DON, ZEN and their metabolites to the status of the horses (sick vs. healthy). A total of 55 clinically healthy horses from 6 different farms with varying feeding background served as control for sick horses (N = 102) hospitalized due to colic. ZEN, alpha-zearalenol (ZEL), beta-ZEL and DON were detecta...
Leukocyte numbers and intestinal mucosal morphometrics in horses with no clinical intestinal disease. Healthy horses and other animals have large numbers of resident leukocytes in the intestinal wall, but there is scant information regarding which and how many leukocytes are normally present in the equine intestinal wall. Our aim was to provide a reference range of leukocytes in the intestinal mucosal and submucosal propria of normal horses. We included in our study intestinal tissues from 22 Thoroughbred racehorses with no clinical intestinal disease, which had been euthanized because of catastrophic musculoskeletal injuries. Neutrophils, lymphocytes, eosinophils, macrophages, and plasma cell...
Pharmacodynamics and plasma concentrations of dexmedetomidine with or without vatinoxan as a constant-rate infusion in horses anaesthetized with isoflurane-A pilot study. The aim was to determine the effects of vatinoxan on dexmedetomidine plasma concentrations and effects on cardiovascular and intestinal tissue pharmacodynamics. In a prospective randomized study, six horses were premedicated intravenously with dexmedetomidine 3.5 µg kg followed by a constant-rate infusion of 7 µg kg h (group DEX) and six horses with dexmedetomidine of the same dose (bolus and constant-rate infusion) combined with vatinoxan 130 µg kg followed by 40 µg kg h (group VAT). Anaesthesia was induced with ketamine and diazepam and maintained with isoflurane. Venous bloo...
Sarcocystis neurona, seroprevalence of antibodies in equines and research of oocystis in opossum in Ilhéus – Itabuna microregion, Bahia, Brazil. The aims of this study were to determine the seroprevalence of Sarcocystis neurona antibodies in equines in the Ilhéus-Itabuna microregion (BA), and identify possible factors associated with infection. The presence of sporocysts/oocysts of Sarcocystis spp. was also verified in Didelphis spp. A total of 669 serum samples were collected from equines in 56 properties located in 12 municipalities in the region. Indirect fluorescent antibody test was performed with slides containing merozoites of the S. neurona, using a cut-off titer of 1:80. Occurrence of 7.92% of anti-S. neurona antibodies was o...
Effects of Gasterophilus pecorum infestation on the intestinal microbiota of the rewilded Przewalski’s horses in China. Horse botflies have been a threat to the Przewalski's horses in the Kalamaili Nature Reserve in Xinjiang of China since their reintroduction to the original range. As larvae of these parasites could infest the intestine of a horse for months, they could interact with and alter the structure and composition of its intestinal microbiota, affecting adversely its health. Nonetheless, there are no such studies on the rewilded Przewalski's horses yet. For the first time, this study characterizes the composition of the intestinal microbiota of 7 rewilded Przewalski's horses infected severely by Gaste...
Ischaemic postconditioning reduces apoptosis in experimental jejunal ischaemia in horses. Ischaemic postconditioning (IPoC) refers to brief periods of reocclusion of blood supply following an ischaemic event. This has been shown to ameliorate ischaemia reperfusion injury in different tissues, and it may represent a feasible therapeutic strategy for ischaemia reperfusion injury following strangulating small intestinal lesions in horses. The objective of this study was to assess the degree cell death, inflammation, oxidative stress, and heat shock response in an equine experimental jejunal ischaemia model with and without IPoC. Methods: In this randomized, controlled, experimental in...
Ex Vivo Comparison of a UV-Polymerizable Methacrylate Adhesive versus an Inverting Pattern as the Second Layer of a Two-Layer Hand-Sewn Jejunal Anastomosis in Horses: A Pilot Study. Resection and anastomosis of small intestine during colic can lead to adhesions and recurrent colic. Several methods are available to reduce the rate of adhesions in the postoperative period, such as the use of serosal barriers. Surgical glues form a smooth surface, are fast to apply, and could reduce surgery time when performing anastomosis. A recently developed UV-polymerizable methacrylate adhesive (UV-PMA) is designed to anchor into the biological tissues' top surface offering sealant and a smooth cover over the anastomosis site. This adhesive was used ex vivo on fifteen samples of equine ...
Redundant mesocolonic mesentery in a Shire colt. An unusual condition in a 3-month-old Shire colt presented for colic unresponsive to medical therapy is documented in this report. A redundant mesocolonic mesentery resulting in intestinal displacement and volvulus was diagnosed during exploratory celiotomy. The finding was presumed to be congenital, resulting in a loose anatomic configuration that predisposed the intestine to displacement, torsion, volvulus, and entrapment. Key clinical message: This case demonstrates that congenial anatomical anomalies should be included in the differential of younger animals presented for recurrent conditio...
Incomplete Ileocecal Bypass for Ileal Pathology in Horses: 21 Cases (2012-2019). Incomplete ileocecal bypass can be performed in cases in which an ileal disfunction is suspected but resection of the diseased ileum is not necessary. Objective: To describe the clinical findings, the surgical technique, and the outcome of 21 cases of colic with ileal pathologies that underwent an incomplete ileocecal bypass. Methods: Historical, clinical, and surgical features of cases diagnosed with pathologies involving the ileum or the ileocecal valve that underwent ileocecal anastomosis without ileal resection were retrieved. Clinical (heart rate, duration of symptoms, presence of reflux,...
Equine colic associated with small intestinal epiploic foramen entrapment. Intestinal epiploic foramen entrapment (EFE) is an important differential diagnosis in horses with colic, but disappointing short- and long-term outcomes are reported in the scientific literature. Many horses are euthanased during surgery due to a predicted poor prognosis or due to uncontrollable intraoperative haemorrhage. The ileum is involved in the majority of cases. Several risk factors for the development of EFE are described; crib-biting/windsucking being the most important one. The recurrence rate of EFE is low despite the described risk factors, probably due to spontaneous closure of ...
Ex vivo comparison of ultrasonographic intestinal wall layering with histology in horses: A feasibilty study. Ultrasonography is increasingly being used as a clinical and research method for evaluating the gastrointestinal tract in horses, however published studies comparing ultrasonographic and histologic characteristics of equine intestinal wall layers are currently lacking. Objectives of this prospective, observational, methods comparison, case series study were to compare the layering pattern and thickness of the intestinal wall layers determined using ex vivo and in vivo ultrasonography with those determined using histology. For the ex vivo study, twelve horses were euthanized for reasons unrelat...
Equine small intestinal angiomatosis. Multiple red, raised nodules multifocally distributed along the serosal surface of the normal and the nonviable jejunum were identified in a 24-year-old neutered male horse undergoing surgery for removal of the strangulating lipoma around the jejunum. Histologically, these nodules consisted of many significantly and variably dilated, blood-filled vascular channels lined by a single layer of flattened, well-differentiated endothelial cells with occasional thrombi within a mildly thickened fibrous stroma. A diagnosis of intestinal angiomatosis was proposed. To the best of the authors' knowledge,...
Diagnostic value of plasma and peritoneal fluid procalcitonin concentrations in horses with strangulating intestinal lesions. To assess the diagnostic value of plasma and peritoneal fluid procalcitonin concentrations for identification of horses with strangulating intestinal lesions. Methods: 65 horses with signs of colic of intestinal origin and 10 healthy (control) horses. Methods: For each horse, plasma and peritoneal fluid samples were obtained for a CBC and determination of total protein, procalcitonin, and lactate concentrations. Signalment and clinicopathologic findings were compared among control horses and horses with strangulating and nonstrangulating intestinal lesions. Results: Mean ± SD plasma (274.9 ±...
Preconditioning with lidocaine and xylazine in experimental equine jejunal ischaemia. Pharmacological preconditioning of dexmedetomidine on small intestinal ischaemia/reperfusion injury has been reported in different animal models including horses. Objective: The objective was to assess if xylazine and lidocaine have a preconditioning effect in an experimental model of equine jejunal ischaemia. Methods: Terminal in vivo experiment. Methods: Ten horses under general anaesthesia were either preconditioned with xylazine (group X; n = 5) or lidocaine (group L; n = 5). A historical untreated control group (group C; n = 5) was used for comparison. An established experimental mo...
Small Intestine Ultrasound Findings on Horses Following Exploratory Laparotomy, Can We Predict Postoperative Reflux? Postoperative reflux (POR) is a well-recognized complication after colic surgery in horses, particularly when presenting small intestinal pathology. Even though much has been written about the pathophysiology and management of POR, additional clinical studies are needed to better understand and anticipate this complication. The aim of the study was to provide clinical evidence of ultrasound findings in the postoperative period (three days). The study is based on transcutaneous abdominal ultrasounds of the caudoventral abdomen during the postoperative period (three days), in 58 horses, presente...
Ex vivo comparison of barbed and unbarbed sutures for the closure of caecal and pelvic flexure enterotomies in horses. In this study the caecum and large colon were harvested from 24 slaughtered horses. On each sample, an 8‑cm long enterotomy was performed. Enterotomies were closed using either barbed or unbarbed glycomer‑631. We compared the time to close, appearance, length of suture material, bursting pressure, and costs associated with each type of material. Our findings demonstrated that time to close was significantly shorter (caecum, P = 0.034; pelvic flexure, P = 0.039) using barbed sutures (caecum 610.4 seconds; pelvic flexure 699.3 seconds) than unbarbed sutures (caecum 661.0 seconds, pelvic flex...
Effect of body condition on intestinal permeability in horses. To investigate effects of body condition on permeability of intestinal mucosa in horses. Methods: 13 horses (7 obese and 6 lean) from 8 to 15 years of age. Methods: Body condition score was assessed, and an oral sugar test (OST) was performed to evaluate glucose and insulin dynamics. Horses were allowed a 2-week diet acclimation period and were then euthanized. Tissue samples were collected from the jejunum, ileum, cecum, pelvic flexure, right dorsal colon, and rectum. Mucosal permeability was assessed by measuring transepithelial resistance and lipopolysaccharide (LPS) flux across tissue samp...
Anoplocephala perfoliata Infection in Horses in Iceland: Investigation of Associations Between Intensity of Infection and Lesions. In Iceland, there is at least 1 horse for every 5 human inhabitants, mostly kept on uncultivated rangelands. Although the Icelandic horse is considered robust compared with other breeds, it is nevertheless susceptible to disease. Few studies have investigated the prevalence of intestinal parasites in horses in Iceland. The purpose of this study was to determine the prevalence of the tapeworm, Anoplocephala perfoliata, in horses in Iceland and to explore associations between intensity of infection and the severity of macroscopic pathological lesions in this population. In addition, the relation...
Predictive value of plasma and peritoneal creatine kinase in horses with strangulating intestinal lesions. To determine the ability of plasma and peritoneal creatine kinase (CK) to predict the presence of a strangulating lesion in horses presented for colic. Methods: Prospective clinical study. Methods: Ten healthy control horses and 61 clinical colic cases. Methods: Creatine kinase activity was measured in peritoneal fluid and plasma of 10 healthy horses and 61 horses presenting for colic (40 horses with nonstrangulating lesions and 21 horses with strangulating lesions). Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, requireme...