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The objective of this study was to determine if a correlation exists between the presence of nitric oxide and prostaglandin release in the equine ventral colon smooth muscle, since this relationship may accentuate the inflammatory process during intestinal injury. Tissue was collected from the ventral colon, cut into muscle strips oriented along the circular, longitudinal and taenial layers, and mounted in a tissue bath system. Samples of the bath fluid were collected before, following electrical field stimulation (EFS), and following EFS in the presence of L-NAME, a nitric oxide synthase inhibitor. Muscle strips were also obtained following systemic administration of a cyclo-oxygnease inhibitor and samples were collected using the previously described protocol. Concentrations of prostaglandins were determined in the fluid samples using an ELISA. Electrical field stimulated release of nitric oxide produced a significant increase in prostaglandin production which did not occur in the presence of L-NAME. Systemic administration of flunixin meglumine reduced prostaglandin levels at all sampling periods, although a small increase was present following EFS. The results of this study support the hypothesis that there is a correlation between the release of nitric oxide and the production of prostaglandins in the smooth muscle of the large colon. This association between nitric oxide and prostaglandin may act as an important regulatory mechanism for various physiological mechanisms, such as vascular smooth muscle tone, and may contribute to amplified tissue injury when the induced forms of both enzymes are activated during an inflammatory insult. This suggests that the use and development of COX2 and iNOS inhibitors may help attenuate the inflammatory response following intestinal injury.

症例は64歳，男性．腹部不快感を主訴に他院を受診，注腸検査で横行結腸に約6cmの腫瘍性病変がみられたため当科に紹介された．糖尿病のコントロールが不良であったため，術前2週間の糖尿病教育入院の後に手術を予定した．手術前日は水分のみ摂取可とし，昼よりニフレック2,000mlを内服させた．手術4日前のCT検査では横行結腸に腫瘍による腸重積様の像が認められたが，開腹時腹腔内を検索すると横行結腸には腫瘍がみられず，術中大腸鏡検査で術前腫瘍が位置していた部位に潰瘍性病変を確認した．それ以外に粗大病変がみられなかったため，潰瘍性病変を含む腸管を約10cm切除してD2郭清を施行した．手術切除標本には癌の遺残はなくリンパ節転移もみられなかった．有茎性大腸ポリープの自然脱落はまれであるが，巨大ポリープの場合，手術前処置が脱落を誘発する可能性があるので注意を要すると考えられた．

Summary Reasons for performing study: The post operative response of the large colon wall after a surgically corrected large colon volvulus (LCV) has not been investigated. Objectives: To use transabdominal ultrasound to monitor the post operative change in large colon wall thickness following surgical correction of LCV. Hypothesis: A prolonged period to colon wall involution is correlated with an increased rate of post operative morbidity and mortality. Methods: A prospective clinical study including horses that presented to the North Carolina State University Veterinary Teaching Hospital for colic between September 2006 and March, 2008, had surgically diagnosed and corrected LCV (at least 360°) without resection and recovered from anaesthesia. Ultrasound of the ventral large colon was performed at the time of anaesthetic recovery and every 6–8 h until the colon wall returned to normal thickness (≤5 mm). Outcome was evaluated using a one-way ANOVA to compare average time to colon wall involution between: 1) survivors and nonsurvivors; and 2) horses that developed multiple organ dysfunction syndrome (MODS) during the post operative period and those that recovered without evidence of MODS. Results: Sixteen horses that recovered without evidence of MODS had a significantly shorter period to colon wall involution (≤5 mm) compared to those diagnosed with MODS (mean ± s.e. 19.6 h ± 2.5 and 39.7 h ± 6.7 respectively, P = 0.006). There was no significant difference in mean period to colon wall involution between survivors and nonsurvivors (26.2 ± 4.9 and 33.2 ± 7.8 h, respectively). Conclusions: A shorter time to colon wall involution was associated with decreased post operative morbidity in horses presented for surgical correction of large colon volvulus without resection. Potential relevance: Ultrasonographic monitoring of colon wall involution after surgical correction of LCV may aid in identifying those cases at risk of MODS. Further investigation of colon wall involution time using a larger number of horses is warranted.

São descritos cinco casos de enterite granulomatosa associada a larvas de ciatostomíneos em eqüinos provenientes de três propriedades rurais do Rio Grande do Sul. Os casos ocorreram entre janeiro de 1999 e dezembro de 2007. A evolução clínica nos dois casos cujo seguimento clínico foi acompanhado foi de 10 e 14 dias. Os sinais clínicos apresentados por três eqüinos foram semelhantes e consistiam de diarréia (3/3), emagrecimento (2/3), pirexia (1/3), taquicardia (1/3) e taquipnéia (1/3). Os achados macroscópicos incluíram espessamento da parede do cólon maior e ceco por edema e ocorrência de numerosos pontos marrom-escuros com 1-4mm, levemente salientes, disseminados pela mucosa. A incisão desses pontos revelou pequenas larvas de nematódeos marrom-avermelhadas de 1-2mm. Numerosos parasitas, compatíveis morfologicamente com pequenos estrôngilos, foram observados na luz intestinal ou aderidos à mucosa do cólon maior e ceco. Histologicamente, na mucosa e submucosa do cólon maior e ceco, foram observados múltiplos granulomas constituídos por moderado ou acentuado infiltrado inflamatório, composto por macrófagos, macrófagos epitelióides e eosinófilos circundados por linfócitos e plasmócitos. No centro desses granulomas, observaram-se cortes transversais de parasitas com morfologia compatível com ciatostomíneos. Adicionalmente, havia edema e infiltrado inflamatório linfo-histioplasmocitário e eosinofílico, leve ou moderado na submucosa e mucosa do cólon maior e ceco; necrose e proliferação linfo-histiocítária em folículos linfóides na submucosa e hiperplasia de células caliciformes na mucosa. O diagnóstico de enterite granulomatosa associada a ciatostomíneos foi realizado com base nos achados epidemiológicos, clínicos e macroscópicos e confirmado pela histologia. Five cases of granulomatous enteritis associated with cyathostomes are described in horses from three farms in Rio Grande do Sul, Brazil. The cases occurred from January 1999 to December 2007. The clinical course in two cases in which clinical follow-up was available was 10-14 days. Clinical signs presented by two horses were similar and included diarrhea (3/3), weight loss (2/3), pyrexia (1/3), tachycardia (1/3), and tachypnea (1/3). Gross changes consisted of thickening of the wall of large colon and cecum by edema and the occurrence of numerous 1-4mm, dark-tan, slightly raised multifocal pinpoints disseminated throughout the mucosa. Up on the incision of these pinpoints, brown-reddish, small (1-2mm) nematode larvae emerged. Large numbers of parasites with morphology compatible with small strongyles were observed in the lumina of large colon and cecum or adhered to the mucosae of these organs. Histologically, multiple granulomas were seen in the mucosa and submucosa of large colon and cecum. These granulomas consisted of moderate to severe inflammatory infiltrate of macrophages, epithelioid macrophages, and eosinophils surrounded by fewer lymphocytes and plasma cells. In the center of these granulomas, transversal cut sections of parasites with morphology compatible with cyathostomes larvae were observed. Additionally, there was edema and moderate to marked lymphohistioplasmacytic and eosinophilic inflammatory infiltrate throughout the mucosa and submucosa of the large colon and cecum; necrosis and lymphohistiocytic proliferation in the submucosal lymphoid follicles, with hyperplasia of goblet cells in the epithelial lining of these organs were also observed. The diagnosis of granulomatous enteritis associated with larval cyathostomiasis was made based on epidemiological, clinical, and gross findings which were confirmed by histopathology.

Intestinal obstruction due to foreign body ingestion is one cause of colic in horses. Although it occurs more frequently in juveniles, adult horses also may be affected. The small colon is a common location in which foreign bodies can be found. Depending on the location of the obstruction in the small colon, different techniques to dislodge the foreign body toward areas where it can be safely exteriorized and removed can be attempted. Alternatively, different approaches to the abdomen can be performed to facilitate exteriorization of the obstructed segment and removal of the foreign body. This paper describes a case of large and small colon obstruction in an adult horse caused by two distinct foreign bodies. The large colon obstruction was removed through a pelvic flexure enterotomy using the ventral midline approach, and the small colon obstruction was removed through a small colon enterotomy using a paramedian approach. Information regarding signalment, history, clinical signs, surgical treatment, and follow-up status of the horse are described.

Objective— To report complications and survival after large colon resection and end-to-end anastomosis in horses with strangulating large colon volvulus. Study Design— Retrospective case series. Animals— Horses (n=73) with strangulating large colon volvulus. Methods— Records (January 1995 to December 2005) of horses that had large colon resection and anastomosis for strangulating large colon volvulus were reviewed for complications. Follow-up data were obtained by telephone questionnaire at least 1 year postoperatively. Cox proportional hazards model was used for multivariate association with survival time. Variables included admission date, age, temperature, heart rate, packed cell volume, total plasma protein concentration, white blood cell count, breed, and sex. Significance was set at P1 year) returned to their intended use (37 brood mares, 2 racehorses, and 1 show horse) with no chronic problems related to the surgical procedure. Conclusion— None of the variables examined were associated with survival. Outcomes were similar to other large studies of surgical colic in the horse. Self-limiting diarrhea is common after large colon resection and the prognosis for survival after hospital discharge is favorable. Clinical Relevance— Horses that survive the early postoperative period and are discharged after large colon resection and anastomosis have a good chance for long-term survival with minimal negative impact on quality of life and use.

Summary Reasons for performing study: Several therapeutic agents have been tested in models of ischaemia and reperfusion injury (IRI) in equine jejunum, with mixed results. This study was based on the use of an organ perfusion solution (OPS) designed to protect human allografts from IRI. Hypothesis: A modified OPS can preserve the integrity of equine large colon during 12 h of isolated pulsatile perfusion, in the absence of oxygen and blood. Methods: Segments of large colon were removed from anaesthetised horses, the contents removed and the mucosa rinsed with 0.9% saline. Experimental segments were perfused for 12 h with one litre modified OPS (n = 7) delivered by pulsatile flow through an extracorporeal circuit. Control segments (n = 4) were perfused on the same circuit with one litre of autologous blood. Vascular resistance, flow and pressure were measured serially, and aliquots of OPS and blood drawn hourly for routine biochemical analyses. Mucosal biopsies of the experimental and control segments were taken at 0, 6 and 12 h and in vivo mucosal tissue at 0 h for baseline comparison. All biopsies underwent histomorphometric analysis and immunohistochemical assessment of calprotectin activity. Results: All colon segments were machine perfused without technical complications. Vascular and biochemical indices remained constant over 12 h in the OPS group, and were constant over 6 h in the control group, but deteriorated later. Mucosal integrity, expression of cyclooxygenases-1 and -2, and expression of mucosal calprotectin were unchanged in the OPS group compared with the baseline tissues, and mucosal integrity was superior to the control tissues. Conclusions: A modified OPS designed to target specific pathways of damage from IRI can preserve colonic mucosal integrity for 12 h in the absence of blood and oxygen. Potential relevance: This extracorporeal system has the potential to preserve equine colon for humane investigation into colonic function and repair over longer periods than previously described for other in vitro and ex vivo systems. Future investigations into use of the modified OPS on injury to equine colon from ischaemia and reperfusion are recommended.

Summary Reason for performing study: The cytosolic protein complex, calprotectin, is abundant in neutrophils and could be used to improve the ability to localise and assess neutrophil infiltration in the equine intestine during ischaemia and reperfusion (I/R), but further study is required. Objectives: To assess the number of calprotectin-containing cells by immunohistochemistry in correlation with direct counting and scoring of neutrophils in the equine colon during I/R. Methods: One and 2 h ischaemia of the left dorsal colon were induced, followed by 30 min reperfusion under general anaesthesia or by 18 h reperfusion after anaesthetic recovery. Biopsies were processed for light microscopy and stained with H&E for detection of neutrophils. To identify calprotectin-containing cells, immunohistochemistry was performed on formalin-fixed tissues with the murine MAC 387 antibody and a biotin-free peroxidase staining procedure. The number of neutrophils within submucosal venules and the colonic mucosa were calculated and compared with the number of calprotectin-positive cells. Results: The number of calprotectin-positive cells within submucosal venules and within the colonic mucosa correlated significantly with the accumulation of neutrophils within the corresponding tissue segments. Within the submucosal venules, both calprotectin-positive cells and H&E-stained neutrophils increased with duration of ischaemia and peaked after 30 min of reperfusion. After 18 h reperfusion the number of these cells declined within the vessels. After 2 h ischaemia, neutrophils started to migrate into the mucosa towards the epithelium, with a significant increase over time during reperfusion, and peak infiltration after 18 h reperfusion. Conclusions: Neutrophil infiltration into the colon after I/R is a time-dependent process, involving migration through the submucosa towards the epithelium. Potential relevance: Immunohistochemical staining for calprotectin can be used to demonstrate the pattern of neutrophil accumulation and migration following I/R.

Summary An 18-month-old pony filly was examined for acute colic and abdominal distension. The signs of colic failed to resolve following analgesic treatment. At exploratory laparotomy, a right dorsal displacement of the large colon was identified and corrected. On recovery from anaesthesia, the pony developed signs of widespread myopathy, confirmed by serum biochemistry evaluations. Myopathy consistent with atypical myoglobinuria was confirmed post mortem.

In virtual colonoscopy, the clinical need is a smooth centered path from the rectum to the cecum, for interactive navigation along the colonic lumen. The primary challenge is breakages in the colon, due to fecal residue, abnormalities, poor insufflation and inadequate electronic cleansing. Here we propose a method, that is a modification of the classic energy minimized geodesic, that extracts centered paths through fragmented colons. To begin, we perform electronic cleansing, automatically localize 4 points: rectum, cecum, sphlenic and hepatic flexures; followed by region growing and heuristic approaches to generate the initial segmentation. This is followed by a daisy chaining procedure to link possibly large colon blobs that may have been missed as weaker candidate segmentations. We then perform a front propagation to extract a minimal energy path through the ordered set of points. This propagation is guided by multiple forces: (a) A strong force given by the distance to the colon segmentation surface (b) A weak force derived from the CT intensity (c) A weak force from the distance to the surface of weaker candidate colon segmentations (d) A geodesic repulsive force, where the other points exhibit an repelling force in their voronoi partition, the force proportional to the geodesic distance to the point. Our contribution is a path extraction method for the colon that is the energy minimized geodesic (a) favouring centeredness (b) punching through gaps, traversing in so far as possible through lower intensity regions and possibly centered within these gaps (c) ordered through the feature points. Results show improvements of the method over the standard minimal energy path approach.

Tympany and impaction are the most common medical conditions encountered, but a wide range of anatomical disarrangements also exist. The large colon has a fluid volume of around 50-60 litres in an adult 500 kg horse, which is similar to the caecum. It is attached to the dorsal body wall and caecum on the right side, leaving the left side unattached and free to move. It is arranged in a double U-shape with three 180-degree turns, or flexures: the sternal, pelvic and diaphragmatic flexures separating right and left ventral, left dorsal and right dorsal colons respectively. This is demonstrated in Fig. 1. The pelvic flexure is both the tightest turn and the narrowest part of the large colon. Neural pacemaker cells found here, the interstitial cells of Cahal, are thought to be responsible for a significant part of large colon motility; deficiency of these cells is seen in some horses suffering recurrent large colon disease.

O equilíbrio ácido-base foi estudado em eqüinos com compactação experimental do cólon maior após o uso de solução isotônica poliônica enteral, sene mais hidratação intravenosa e hidratação intravenosa. As amostras sangüíneas foram colhidas de 20 animais, quatro grupos (E8, RL, SE e C) de cinco animais cada. Os animais dos grupos tratados eram portadores de compactação no cólon maior induzida experimentalmente. Eqüinos no grupo E8 receberam solução isotônica poliônica enteral (8mL kg -1 h -1 48h -1 ); no grupo SE, sene foram administrados na dose de 20mg kg -1 , duas doses de 24/24h, mais Ringer lactato intravenoso, 10mL kg -1 h -1 12h -1 , durante dois dias; sendo que o grupo RL recebeu Ringer lactato intravenoso (16mL kg -1 h -1 12h -1 ) durante dois dias. O grupo C, controle, não foi tratado. Entre os tratamentos testados, a fluidoterapia intravenosa com solução de Ringer lactato (RL) foi o tratamento mais eficiente para a correção das variáveis hemogasométricas em eqüinos com compactação do cólon maior. A solução isotônica poliônica enteral (E8) e sene associada com fluidoterapia intravenosa (SE) foram eficientes, porém em menor grau. The blood acid-base status was studied in equines when induced large colon impaction was followed by applying an isotonic polionic enteral solution, or sene associated with intravenous fluid therapy, or fluid therapy alone. The blood samples were collected in twenty animals, four groups (E8, RL, SE, and C) of five animals each. Animals of the treated groups had experimentally induced colon impactions. Equines in group E8 received isotonic polionic enteral solution (8 mL kg -1 h -1 48 h -1 ); in group SE, sene was applied at 20mg kg -1 , two doses per animal, at 24-hour intervals, along with the Ringer lactate IV, 10mL kg -1 h -1 , 12 h -1 , both during two days; and in the RL animals received Ringer lactate IV only (16mL kg -1 h -1 12h -1 ), applied during two days. Group C was the non-treated control. Among the tested treatments, the intravenous fluid therapy with Ringer solution (RL) alone was the most efficient to correct the blood gas parameters in horses with large colon impaction. The isotonic polionic enteral solution (E8) and sene associated with intravenous fluid therapy (SE) were also efficient, although less so than Ringer solution alone.

Colon cancer accounts for a large proportion of all the cancer-associated morbidities worldwide. Genetic analysis and stratification of patients based on survival may identify genetic signatures potentially useful for prognostic or treatment planning purposes. Previous studies have reported that the messenger (m)RNA expression levels of tafazzin (TAZ), AXL receptor tyrosine kinase (AXL) and connective tissue growth factor (CTGF) were able to predict the survival of patients with colon cancer in two independent colon cancer datasets. However, limited clinicopathological data were available from these two datasets. By contrast, a large colon cancer dataset comprising 566 patients has been recently published in the Gene Expression Omnibus database, which contains data regarding tumor stage and location, and genetic status of mismatch repair (MMR), Kirsten rat sarcoma viral oncogene homolog (KRAS), B-Raf proto-oncogene serine/threonine kinase (BRAF) and tumor protein p53 (TP53). In the present study, the mRNA expression levels of TAZ, AXL and CTGF were evaluated, and the TAZ-AXL-CTGF signature was correlated with the available pathological parameters and survival data. Overexpression of TAZ, AXL and CTGF was observed to be associated with severe pathological stage, deficiency in MMR, colon cancer subtype C4 and mutations in the BRAF gene. In addition, overexpression of TAZ-AXL-CTGF was associated with short overall survival in patients with mutations in the TP53 gene, colon cancer subtype C6, proficient MMR and wild-type status of the KRAS and BRAF genes. Furthermore, the prognostic value of TAZ-AXL-CTGF overexpression was observed to be independent of all the clinicopathological parameters and mutational statuses analyzed. The results of the present study confirm the previously reported findings, and suggest that the TAZ-AXL-CTGF mRNA signature is a potential prognostic indicator in colon cancer.

To evaluate use of a knotless suture for laparoscopic closure of the equine nephrosplenic space.Experimental in vivo study.Normal horses without previous history of abdominal surgery (n=8).The nephrosplenic space was closed under laparoscopic visualization using a unidirectional, barbed 0 metric absorbable suture (copolymer of glycolic acid and trimethylene carbonate). Intracorporeal suturing of the nephrosplenic space was performed in a cranial-to-caudal direction in a simple continuous fashion. Repeat evaluation was performed laparoscopically in 2 horses and by necropsy in 6 horses. The length of closure was measured and nature of the healed tissue was evaluate grossly.Total surgery time was 65-167 minutes (mean ± SD, 89.6 ± 22.6). Suturing time was 30-65 minutes (40.4 ± 16.3). Second laparoscopy in 2 horses was performed at days 198 and 227. Necropsy was performed at day 69-229 postoperatively (132.7 ± 63.0) in 6 horses. The closure measured 12-14 cm in length (13 ± 1) and consisted of mature fibrous tissue bridging the splenic capsule and the nephrosplenic ligament. No residual suture material was identified grossly in any horses. The procedure was easily performed; extracorporeal suture management to hold it taut was unnecessary since the barbs had excellent purchase in the apposed tissues, and intracorporeal knot tying was not required.The barbed knotless suture appears to be a valid alternative to facilitate laparoscopic closure of the nephrosplenic space in normal horses; however, further work is necessary to investigate its suitability in clinically affected horses.

Oncogene-induced senescence (OIS), a tumor-suppressive mechanism that is induced by the replicative and metabolic stress of oncogene activation, is a key barrier in the development of BRAF V600E colon cancer. Inhibition of this mechanism has been observed through epigenetic changes observed in sporadic serrated polyps, as well as through the germline mutations associated with those who develop serrated polyposis. We hypothesize that upregulated autocrine factors exist that are specific to the serrated pathway and also promote bypass of oncogene-induced senescence. To identify such autocrine factors, we integrate analyses of microarrays of sessile serrated polyps and two large colon cancer cohorts, the Cancer Genome Atlas (TCGA; n = 153), and French national Cartes d'Identité des Tumeurs (CIT) program (n = 462), with enhanced gene annotation through natural language processing techniques of the existing medical corpus. We reproducibly associate higher expression of the ligand–receptor axis of TFF2 and CXCR4 with BRAF V600E-mutant colon cancer (P = 3.0 × 10−3 and 0.077, respectively for TCGA; P = 3.0 × 10−8 and 5.1 × 10−7 for CIT). Given well-described oncogenic roles of TFF2 and CXCR4 in colon cancer, and availability of CXCR4 inhibitors for other clinical indications, this ligand–receptor axis may represent an actionable target for prevention and treatment of this molecular subtype of colorectal cancer. Cancer Prev Res; 8(7); 614–9. ©2015 AACR.

Intra-abdominal adhesions are equine surgery complications, which can result in obstructive processes and jeopardize the survival of these animals. The present study used 10 healthy, male mongrel horses (SRD), with four and 15 years of age and weighing between 300 and 400 kilograms (kg), who underwent laparotomy left station with the aim of inducing adhesions, test intestinal membrane using pericardium as prevention and evaluating the different systemic changes and the abdominal fluid. After sedation and local anesthesia, the surgical approach was used in grade; pelvic flexure was created in an area of abrasion that in Group 1 was covered by homologous pericardium and in Group 2, washed with saline. After repositioning muscle, the skin and subcutaneous tissue were sutured. Postoperative care consisted of clinical evaluation, abdominal fluid cytology, hematology and serum biochemistry in moments M0- preoperative, and M7, M14, M21 and M28 days postoperatively. New laparotomy was performed at 30 days from the surgery to verify adhesion, appearance and intestinal biopsy. The surgical technique allowed less trauma and restricted operative field. The clinical course was satisfactory, and fibrous scar was identified between the muscle planes. Adhesions were not observed. Laboratory evaluations showed increased bilirubin, hematocrit, monocyte, blood urea and protein density and segmented leukocyte peritoneal fluid. The present study concluded that the abrasion was insufficient to promote fibrous adhesions. The implant without proven efficacy is feasible and possible, and does not result in significant differences laboratory or deleterious changes. Aderências intra-abdominais são complicações de cirurgias de equinos que podem resultar em processos obstrutivos e comprometer a sobrevida dos animais. O presente estudo utilizou dez equinos hígidos, machos, sem raça definida (SRD), com quatro a 15 anos de idade e peso vivo situado entre 300 e 400 quilogramas (kg). Os animais foram submetidos à laparotomia esquerda em estação com o objetivo de serem induzidas aderências, testar a utilização intestinal de membrana biológica de pericárdio como prevenção e avaliar as diferentes alterações sistêmicas e do líquido abdominal. Após sedação e analgesia local, foi utilizado o acesso cirúrgico em grade, na flexura pélvica foi criada uma área de abrasão que, no Grupo 1, foi coberta por pericárdio homólogo e no Grupo 2, lavada com solução fisiológica. Após reposicionamento foi realizada a sutura muscular, de subcutâneo e pele. O pós-operatório constou de avaliações clínicas, citologia do líquido abdominal, hematologia e bioquímica sérica nos momentos M0- pré-operatório e M7, M14, M21 e M28 dias de pós-operatório. Nova laparotomia foi realizada aos 30 dias para verificar aderências, aspecto e biópsia intestinal. A técnica cirúrgica possibilitou menor trauma e campo operatório restrito. A evolução clínica foi satisfatória e cicatriz fibrosa foi identificada entre os planos musculares. Aderências não foram observadas. As avaliações laboratoriais demonstraram aumento de bilirrubinas, hematócrito, monócito, ureia sanguíneos e de proteína, densidade e leucócitos segmentados no líquido peritoneal. Conclui-se que a abrasão foi insuficiente para promover aderências fibrosas. O implante, sem comprovada eficácia, é viável e possível, por não resultar em diferenças laboratoriais significativas ou alterações deletérias.

A 2-year-old dappled Percheron horse had a wasting condition that did not respond to antibiotic treatments and ultimately resulted in death. Thickening of the wall of the large colon and enlargement of the mesenteric lymph nodes were observed at postmortem examination, along with the presence of pinpoint whitish foci in the liver. Microscopic examination of affected tissues revealed diffuse chronic granulomatous enterocolitis, granulomatous mesenteric lymphadenitis, and multifocal granulomatous hepatitis. The DNA extracted from paraffin-embedded intestinal and lymph node samples was analyzed using both a polymerase chain reaction (PCR) assay and PCR–restriction endonuclease analysis and demonstrated the presence of Mycobacterium bovis.

Objective—To identify factors associated with development of small colon impaction in horses and with selection of medical versus surgical treatment and to determine the prognosis for affected horses following medical or surgical management. Design—Retrospective case series. Animals—44 horses with primary impaction of the small colon. Procedures—Medical records were reviewed for signalment, history, clinical findings, treatment (medical vs surgical), hospitalization time, and outcome. For comparison purposes, the same information was collected for 83 horses with primary impaction of the large colon. Results—Diarrhea was the only factor found to be associated with development of small colon impaction. Horses with small colon impaction were 10.8 times as likely to have diarrhea at the time of initial examination as were horses with large colon impaction. Abdominal distension was the only factor associated with use of surgical versus medical treatment. Horses with small colon impaction that were treated surgically were 5.2 times as likely to have had abdominal distension at the time of admission as were horses with small colon impaction that were treated medically. Overall, 21 of 23 (91%) horses treated medically and 20 of 21 (95%) horses treated surgically survived to discharge. Conclusions and Clinical Relevance—Results suggest that diarrhea may be a risk factor for development of small colon impaction and that horses with small colon impaction that have abdominal distension at the time of initial examination are more likely to require surgical than medical treatment.

Ultrasonographic examination of the abdomen in the adult horse yields information about the gastrointestinal tract and abdominal organs that is difficult or impossible to obtain through other diagnostic modalities available to the equine practitioner. The majority of the spleen, both kidneys, and part of the liver can be examined ultrasonographically from a percutaneous approach, and the left kidney can be examined transrectally in most adult horses. The portions of the small intestine and large colon adjacent to the body wall can be evaluated ultrasonographically and assessments made about its luminal contents, motility, and wall thickness, helping the surgeon to decide in a colicky horse if surgical intervention is necessary. A portion of the stomach is also imaged along the left body wall in adult horses. Transrectal ultrasonographic examination of the left kidney, cranial mesenteric root and its vessels, bladder, ureters, duodenum, small intestine, and small and large colon is useful if there are palpable abnormalities detected on rectal examination or if the transcutaneous image is of poor quality. Additional diagnostic information can be obtained about the quantity and character of the peritoneal fluid in horses using diagnostic ultrasound.

Large-colon torsion is a common cause of colic in horses and has a worse prognosis and higher cost than other causes of surgical colic of the large colon. During large-colon torsion, the colon wall becomes thick due to vascular occlusion. Therefore, we hypothesized that detecting increased colon wall thickness during ultrasonography would be an accurate preoperative test for large-colon torsion. The sample population consisted of 42 horses that were admitted for surgical treatment of colic localized to the large colon. The diagnosis was confirmed at surgery or necropsy examination. Twelve (29%) of these horses were diagnosed with large-colon torsion. Duplicate ultrasonographic measurements of colon wall thickness were made at six abdominal locations and an average measurement was calculated. For four of these six sites, a significant difference (P0.005) was detected between horses with and without large-colon torsion. All four tests were moderately sensitive and highly specific for diagnosing large-colon torsion using five decision criteria. Using a ventral abdominal window, a colon wall thicknessor = 9 mm accurately predicted large-colon torsion in eight of the 12 horses (sensitivity, 67%; confidence interval [CI], 36-98%) and correctly predicted that large-colon torsion was absent in 28/28 horses (specificity 100%; CI, 98-100%). Intraobserver repeatability was assessed by evaluating the difference between the first and second measurements obtained, which wasor = 2 mm. Therefore, detecting increased large-colon wall thickness during ultrasonography is a reproducible and accurate preoperative test for large-colon torsion in horses with surgical colic localized to the large colon.

This paper reports one case of a horse with acute colic syndrome that was referred to the Teaching Hospital Complutense of Madrid. Based on the history, clinical signs and complementary diagnostic tests, a colon displacement was diagnosed. In the exploratory celiotomy, a right dorsal displacement of the large colon and generalized enteritis were found. During the surgery, adhesions all along the small intestine and multiple diverticula of different size in the mesenteric border in portions of the jejunum were also found. Due to these findings and the poor condition of the patient, euthanasia was performed on human grounds. This case report concludes that attending veterinarian should include this uncommon pathology in their differential diagnosis when chronic signs of colic, weight loss or diarrheas are a feature.

Ultrasonography has proven to be very useful for evaluation of the urinary and gastrointestinal tracts in foals and adult horses. Gastric distension, small intestinal ileus, inflammation of the large intestine, right dorsal colitis, intraabdominal masses and neoplasia, intraabdominal abscesses, intussusceptions, ileal muscular hypertrophy, intraluminal ascarids, inguinal herniation, impactions, entrapment of the large colon in the nephrosplenic space, liver lobe torsions, colelithiasis, diaphragmatic hernias, displacement of the colon, peritonitis, intraabdominal hemorrhage, and bowel rupture can be detected by abdominal ultrasound. Ultrasound can be used to guide liver biopsies and abdominocentesis. For the latter, accumulations of peritoneal fluid can be localized and inadvertent puncture of the spleen and intestine can be avoided. Assessment of peristalsis by ultrasonography is subjective but valuable, and horses with small intestinal obstruction in this study had either pendular peristalsis or complete atony. In 67 horses with small intestinal obstruction in this study, all cases were diagnosed beforehand by ultrasonography, whereas 10% were missed by rectal palpation. Four horses were incorrectly diagnosed with nephrosplenic ligament entrapment of the large colon by ultrasonography (false positive), but ultrasonographic absence of this lesion in other horses was confirmed at surgery. Percutaneous ultrasound is non invasive, is not restricted to foals, ponies, or others that are too small for rectal palpation, requires little time, and can be useful in the decision for surgical or medical treatment.

This report describes the use of ultrasound to diagnose right dorsal displacement of the large colon (RDDLC) in 13 horses prior to surgery. Horses had ultrasonographic examinations performed of the right lateroventral aspect of the abdomen upon admission to the hospital with a 2-5 MHz broadband curvilinear sector scanning transducer after alcohol was used to wet the hair. First, the caecal vessels were identified in the right flank and followed medially and cranially. Next, each intercostal space, from caudal to cranial, was scanned from dorsal to ventral evaluating for abnormally-located mesenteric vessels associated with the large colon. Abnormally-located mesenteric vessels associated with the large colon, distinct from the caecal vessels, were identified in 13 of 23 horses with a diagnosis of RDDLC obtained at exploratory laparotomy. In horses, ultrasonographic visualisation of mesenteric vessels along the right lateral abdomen, dorsal to the costochondral junction in at least 2 intercostal spaces, distinct from the caecal vessels, is consistent with a surgical diagnosis of RDDLC.

Background\ud \ud Large colon impactions are a common cause of colic in the horse. There are no scientific reports on the clinical presentation, diagnostic tests and treatments used in first opinion practice for large colon impaction cases. The aim of this study was to describe the presentation, diagnostic approach and treatment at the primary assessment of horses with large colon impactions.\ud \ud Methods\ud \ud Data were collected prospectively from veterinary practitioners on the primary assessment of equine colic cases over a 12 month period. Inclusion criteria were a diagnosis of primary large colon impaction and positive findings on rectal examination. Data recorded for each case included history, signalment, clinical and diagnostic findings, treatment on primary assessment and final case outcome. Case outcomes were categorised into three groups: simple medical (resolved with single treatment), complicated medical (resolved with multiple medical treatments) and critical (required surgery, were euthanased or died). Univariable analysis using one-way ANOVA and Tukey’s post-hoc test, Kruskal Wallis with Dunn’s post-hoc test and Chi squared analysis were used to compare between different outcome categories.\ud \ud Results\ud \ud 1032 colic cases were submitted by veterinary practitioners: 120 cases met the inclusion criteria for large colon impaction. Fifty three percent of cases were categorised as simple medical, 36.6% as complicated medical, and 9.2% as critical. Most cases (42.1%) occurred during the winter. Fifty nine percent of horses had had a recent change in management, 43% of horses were not ridden, and 12.5% had a recent / current musculoskeletal injury. Mean heart rate was 43bpm (range 26-88) and most cases showed mild signs of pain (67.5%) and reduced gut sounds (76%). Heart rate was significantly increased and gut sounds significantly decreased in critical compared to simple medical cases (p

Five healthy green iguana (Iguana iguana) were used to determine appropriate technique and normal transit times for gastrointestinal contrast studies and to describe normal radiographic anatomy. The animals were maintained at 27-29 degrees C. There was rapid transit through a U shaped stomach, with a median gastric emptying time of 8 h, and median small intestinal transit and small intestine emptying times of 4 h and 16 h respectively. Median large colon transit and emptying times were 15 h and 66 h. Maintaining the iguana at a reduced ambient temperature increased all of these times. The vaso-vagal response or mechanical methods were adequate for restraint. A 25 ml/kg dose of a 25% w/v suspension of barium administered by stomach tube gave the best results. Lateral and ventrodorsal projections of the abdomen should be made immediately following the administration of the barium and at 1-hour intervals for the first 6 h and at 12-hour intervals thereafter until barium can be identified in the distal descending small colon.

Objective—To determine efficacy of an extracorporeal circuit to maintain a segment of equine large colon for 3.5 hours and to evaluate the effect of low arterial flow on histologic and metabolic variables. Sample Population—Segments of large colon from 15 healthy adult horses. Procedure—The pelvic flexure was surgically removed and maintained in an isolated circuit. In the control group, tissue was evaluated for 3.5 hours, whereas in the low-flow group, arterial flow was reduced to 20% of baseline for 40 minutes followed by 2 hours of reperfusion. Various metabolic and hemodynamic variables were evaluated at 30-minute intervals. Effects of nitric oxide (NO) and L-N-nitro-arginine- methyl-ester (L-NAME) on contractile activity were determined, and histomorphologic evaluation was performed at the completion of the study. Results—Low-flow ischemia with reperfusion caused significant histomorphologic differences, compared with the control group. In the low-flow group, significant differences included reduction in PaCO2, reduction in bicarbonate concentrations, increase in PaO2, and an increase in base deficit in arterial and venous blood samples. Other significant differences included increases in PCV, protein concentration, total WBC count, and albumin clearance for the low-flow group. Differences were not detected in inhibitory activity of the low-flow group relative to the control tissue with or without addition of NO and L-NAME. Conclusion—The extracorporeal circuit maintained a segment of equine intestine for 3.5 hours and can be used to simulate ischemic injury. The extracorporeal circuit provides the potential to investigate pharmaceutic agents that can minimize intestinal injury. (Am J Vet Res 2000;61:1042–1051)

Objectives— To report a surgical technique for treatment of nonreducible cecocolic intussusception and outcome in 8 horses. Study Design— Retrospective study. Animals— Eight horses with nonreducible cecocolic intussusception treated by cecal amputation through a right ventral colotomy. Methods— Data were obtained from medical records and telephone conversations by using a standardized questionnaire. The large colon was exteriorized and, if necessary, evacuated of its contents through a pelvic flexure enterotomy. A second colotomy was made on the ventral surface of the right ventral colon (RVC) centered over or immediately distal to the intussusceptum. In most horses, attempts to manually reduce the intussusception by pushing the cecum from within the RVC through the cecocolic orifice were unsuccessful. Invaginated cecum was then pulled into the RVC and amputated; the cecum was either ligated with umbilical tape or sutured proximal to the site of amputation. After amputation, the remainder of the invaginated cecum was reduced. After further resection to healthy tissue, the typhlectomy was closed with a double-inverting suture pattern. Results— The median horse age was 2 years (range, 1 to 8 years). Duration of colic ranged from 6 hours to 6 months. Median surgical time was 180 minutes (range, 135 to 300 minutes). Median duration of antibiotic therapy was 7 days (range, 5 to 14 days). Median duration of hospitalization was 12 days (range, 6 to 21 days). All horses survived to hospital discharge. One horse died 3 months postoperatively; however, the remainder survived (median survival, 30 months; range, 6 to 96 months) and returned to or exceeded previous function. Clinical Relevance— Despite some contamination during surgery, horses with nonreducible cecocolic intussusception that underwent this method of surgical treatment had a good prognosis.

Summary Reason for performing study: It is a clinical impression that horses diagnosed with a right dorsal displacement (RDD) of the large colon, are more likely to suffer from recurrent episodes of colic post operatively, compared to other forms of nonstrangulating large colon displacement. Objectives: To investigate whether the type of nonstrangulating large colon displacement identified at exploratory laparotomy would influence long-term outcome. Hypothesis: Horses identified with a RDD of the large colon at exploratory laparotomy would be more likely to experience recurrent episodes of post operative colic than other types of displacement. Materials and methods: Medical records for horses undergoing an exploratory laparotomy, from 2000–2008, for a nonstrangulating large colon displacement were reviewed. Data retrieved included: subject details, previous medical history, details of current episodes of colic, results of preoperative examination, surgical findings and procedures, post operative management and complications. Follow-up information was obtained by reference to computerised clinical records and by telephone questionnaire administered to the horse's owner or carer, and included details of any colic episodes exhibited by the horse after discharge and whether a repeat celiotomy had been required to resolve the colic episodes. Results: There were 165 surgeries identified, in 154 horses. It was found that those horses with RDD were significantly more likely to experience recurrent episodes of colic requiring veterinary intervention post operatively compared to other types of displacement. Clinical relevance: Long-term prognosis and likelihood of post operative complications is an important consideration for both owners and veterinarians.

This report describes two mares presented for evaluation of anorexia, fever of unknown origin, and weight loss. Clinical examination, laboratory findings, and transrectal ultrasonographic images suggested ovarian abscessation. One mare was successfully treated medically. Because of financial considerations, the second mare was euthanatized and a postmortem examination was performed. At necropsy, there was an enlarged right ovary with an adhesion to the large colon. Microscopic findings were characteristic of an ovarian abscess.

Summary The possibility of stomach impaction resulting in large colon volvulus is raised by authors reporting the findings of both lesions in 7 horses. Although this combination of lesions has not been reported before, it is interesting to consider the effect of a gastric impaction compressing the colon as the stomach increases in size with firm ingesta. Anatomically, the stomach is dorsal to the colon, and might therefore compress the colon. As to how this might result in volvulus, it is interesting to speculate on the possible roles of gas accumulation or other changes in the intracolonic environment, such as composition in microbiota. The report of 7 horses also highlights the need to thoroughly explore any horse taken to surgery because of intractable colic in case there is more than one lesion.

A eficiência da fluidoterapia por via enteral foi avaliada em 14 eqüídeos (12 eqüinos e dois muares) que apresentavam compactação do cólon maior. Os animais tinham entre um ano e meio e 20 anos de idade e todos eram alimentados com capim elefante (Pennisetum purpureum Schumach) triturado. O início dos sinais de cólica foi observado no dia do internamento em seis casos, um dia antes em cinco casos, três dias antes em um caso, quatro dias antes em um caso e seis dias antes em um caso. Um cavalo havia sido banhado com amitraz dois dias antes dos primeiros sinais de cólica. Quando foram internados, todos os animais apresentavam desidratação, dor leve a moderada e intermitente, fezes ressecadas e digesta compactada no cólon maior. Onze animais foram medicados com analgésico. Através de sonda nasogástrica foi administrada água a todos os animais. O volume administrado, de cada vez, foi de no máximo 10 litros e o intervalo entre as administrações foi de no mínimo 30 minutos. O volume total administrado a cada animal variou de 60 a 223 litros (média 119,14 litros). Durante o tratamento, o único ali mento fornecido foi ração à base de grãos e suplemento mineral. Diariamente eram feitos dois exames clínicos e todos os animais apresentaram poliúria, redução gradativa do volume abdominal, amolecimento das fezes e remissão dos sinais de desidratação. O tratamento teve a duração de um a cinco dias (média 2,57 dias). Quando a fluidoterapia foi interrompida, nenhum animal apresentava dor abdominal ou compactação do intestino grosso. Concluiu-se que a fluidoterapia enteral foi eficiente no tratamento de compactação do cólon maior em eqüídeos. The efficiency of enteral fluid therapy was checked in 14 equids (12 horses and two mules) presenting large colon impaction. The age of the animals ranged from 1.5 to 20 years old. All equids were fed chopped "capim elefante" (Pennisetum purpureum Schumach). The first colic signs were observed in the hospitalization day in six cases, one day before in five cases, three days before in one case, four days before in one case, and six days before in one case. One horse was sprayed with amitraz two days before the first colic signs. At hospitalization all animals showed dehydration, mild to moderate intermittent pain, dried feces, and impacted mass in large colon. Eleven animals were medicated with analgesics. Water was administered by nasogastric tube for all animals. The maximum volume administered at each time was 10 liters and the minimum interval between administrations was 30 minutes. The total volume administered for each animal ranged from 60 to 223 liters (mean, 119.14 liters). During treatment the animals were fed only with grain meal and mineral supplement. Two physical exams were done every day and all equids showed poliuria, gradual abdominal volume reduction, feces softening, and regression of dehydration signs. Duration of treatment was one to six days (mean, 2.57 days). At the end of fluid therapy, none animal showed abdominal pain or large intestino impaction. It may be concluded that enteral fluid therapy was efficient to treat large colon impaction in equids.

Objective—To describe an alternative technique for large colon resection and anastomosis in horses. Study Design—Retrospective study of clinical patients. Animal Population—37 horses that had ventral midline celiotomies between July 1, 1990, and July 1, 1994. Methods—Large colon resection and anastomosis was performed using a modification of previously described techniques. Modifications include mesocolon ligation with a stapling device and an end-to-end apposition of the right ventral and right dorsal colon. Results—Twenty-one of the 37 horses were discharged from the hospital without complications. Two horses were euthanatized immediately after recovery from anesthesia because of hindlimb fracture. Fourteen horses were euthanatized in the initial postoperative period because of persistent endotoxemia and abdominal pain. Conclusions—The described technique is a safe, reliable method for large colon resection and anastomosis in horses. Clinical Relevance—The described technique is fairly simple to perform and requires less surgical time compared with other techniques.

Objective—To determine the effect of platelet-activating factor (PAF) antagonist L-691,880 on low-flow ischemia and reperfusion (I-R) of the large colon in horses. Animals—12 adult horses. Experimental Design—Horses were anesthetized, and the large colon was exteriorized through a ventral median celiotomy and instrumented. Colonic arterial blood flow was reduced to 20% of baseline (BL) and maintained for 3 hours; flow was then restored, and the colon was reperfused for 3 hours. One of two solutions was administered intravenously 30 minutes before reperfusion: group 1, 10 mL/kg 0.9% NaCl; and group 2, 5 mg/kg PAF antagonist L-691,880 in 0.9% NaCl. Hemodynamic variables were monitored and recorded at 30-minute intervals. Systemic arterial and colonic venous blood were collected for measurement of blood gas tensions, oximetry analyses, packed cell volume, and total plasma protein concentrations. Colonic venous blood was collected for determination of lactate, 6-keto prostaglandin F1α (6-kPG), prostaglandin E2 (PGE2), and thromboxane B2 (TXB2) concentrations. Full-thickness biopsy specimens were harvested from the left ventral colon for histological evaluation. Results—There were no significant differences between the two groups for any hemodynamic or metabolic variables. Colonic venous pH decreased, and carbon dioxide tension and lactate concentration increased during ischemia but returned to BL values during reperfusion. Colonic venous 6-kPG concentration was significantly increased above BL value at 2 hours and remained increased through 6 hours in horses of both groups. Colonic venous PGE2 concentration was significantly greater in group 2 compared with group 1 throughout the study. Colonic venous PGE2 concentration was increased above BL value from 3 to 6 hours in horses of both groups. Colonic venous TXB2 concentration was not different between groups but was significantly increased above the BL value for the first hour of reperfusion. Low-flow I-R of the large colon caused significant mucosal necrosis, hemorrhage, edema, and neutrophil infiltration; however, there were no differences in histological variables between vehicle-control and PAF antagonist-treated horses. Conclusion—No protective effects of PAF antagonist L-691,880 were observed on colonic mucosa associated with low-flow I-R. Additionally, deleterious drug-induced effects on hemodynamic and metabolic variables and colonic mucosal injury were not observed.

Summary Left dorsal displacement of the large colon is a condition unique to the horse that results in an obstruction of the colon and signs of colic. This condition may be successfully treated medically with analgesia, i.v. or oral fluids and feed restriction, exercise with or without administration of phenylephrine, or rolling under general anaesthesia with or without administration of phenylephrine, or a combination of these conservative options. Surgical correction via standing left flank laparotomy or, more commonly, ventral midline laparotomy under general anaesthesia, is required in cases where conservative therapy is unsuccessful. Recurrence rates range from 3.2% to 21%. Surgical attempts to prevent recurrence of this condition include large colon resection, colopexy, and ablation of the nephrosplenic space.

Displacements and intraluminal obstructions of the large colon carry a good to excellent prognosis for long-term recovery, and surgery for these diseases is rarely followed by short-term or long-term complications. Entrapment of the large colon over the renosplenic ligament is amenable to medical therapies so that surgery can be avoided in many cases. However, preoperative diagnosis of all nonstrangulating diseases of the large colon can be difficult. Vascular diseases of the large colon, such as thromboembolic diseases and large colon volvulus, are more difficult to treat and carry a poorer prognosis for survival.

Impactions have been reported in the stomach and all segments of the intestine. Impactions predominately occur just oral to sites of intestinal narrowing or active pacemakers. The most common sites of impaction are in the ileum, the cecum, and the large colon pelvic flexure. The treatment of gastrointestinal impactions depends on the segment affected and the amount of bowel damage which has occurred from distension. Many impactions respond to appropriate administration of analgesics, cathartics, and oral or intravenous fluids. The prognosis for impactions treated medically is better than for those which require surgery.

Summary Reason for performing study Intraoperative assessment of colonic viability can be challenging and largely subjective. Objective methods are often impractical. Viability is related to re-establishment of colonic perfusion; particularly microvascular perfusion. This study evaluated the utility of dark-field microscopy (DFM) of the colonic serosa as an objective method of assessing microperfusion. Objectives To measure microvascular perfusion indices (MPI) of the pelvic flexure serosa in horses with surgical colonic lesions and correlate these with macroperfusion indices (MaPI) and histomorphometry. Study design Prospective, clinical, case–control study. Methods Control horses and horses with colonic volvulus (LCV), displacement, and/or simple obstruction undergoing surgery had DFM video loops performed on the pelvic flexure. Total vessel density, perfused vessel density, proportion of perfusion vessels and microvascular flow index were calculated from video analysis. Macroperfusion indices (arterial blood pressure and heart rate) were recorded. Histomorphometry was used to determine a mucosal injury score. Differences between lesions for MPI, MaPI and histomorphometry were compared using ANOVA or Kruskal–Wallis statistic. Spearman correlations between MPI with MaPI were performed. Linear regression was used to assess the relationship between MPI and histomorphometry. P

The aim of the study was to determine if horses with large colon impaction were more severely affected by oral pathology than control cases and to relate faecal particle size distribution to dental pathology in both study groups. A prospective study included 39 horses with large colon impaction and 72 control horses from a hospital-based population. An oral pathology score (OPscore) and periodontal disease index (PDI) were assigned to all horses and faecal samples were collected for estimating faecal particle size and analysis of particle size distribution. Horses with large colon impactions were not more severely affected by oral pathology than control horses for both OPscore (P = 0.2) and PDI (P = 0.3). Faecal particle size estimates were significantly higher in control animals (P

Objective—To compare the outcome of horses with nephrosplenic entrapment of the large colon (NSELC) that were treated nonsurgically by IV administration of phenylephrine and exercise with that of horses treated by IV administration of phenylephrine and a rolling procedure under general anesthesia. Design—Retrospective case series. Animals—88 horses with NSELC. Procedures—Horses examined between 2004 and 2010 because of acute abdominal pain that had NSELC on the basis of findings on abdominal palpation per rectum, abdominal ultrasonography, or both were included. Medical records were reviewed to obtain information on treatment (IV administration of phenylephrine and exercise vs IV administration of phenylephrine and a rolling procedure) and outcome. Results—Overall, 85% (75/88) of horses with NSELC responded to exercise or rolling under general anesthesia. The success rate of rolling under general anesthesia (42/50 [84%]) was significantly higher than the success rate of exercise after IV administration of phenylephrine (24/38 [63.2%]). Resolution of NSELC was achieved by rolling under general anesthesia in 8 of 14 horses that initially failed to resolve with exercise. Conclusions and Clinical Relevance—A rolling procedure performed under general anesthesia had a higher success rate than exercise after IV phenylephrine administration for resolution of NSELC in horses, suggesting that rolling could be considered as the initial medical treatment. The rolling procedure may be labor intensive and should only be attempted in a surgical facility in the event that exploratory laparotomy is required

Colonic luminal pressure (median, range) measured during ventral midline celiotomy in 69 horses with strangulating obstruction (SO) of the large colon (SO; > or = 270 degrees large colon volvulus; 27 cm H2O: 2 to 80 cm H2O) was greater (P = .0023) than that measured in 37 horses with nonstrangulating obstruction (NSO) of the large colon (NSO; < or = 180 degrees volvulus or a nonstrangulating displacement; 18 cm H2O; 6 to 46 cm H2O). Sixty-five percent (45 of 69) of horses with SO and all horses with NSO survived. Survival analysis was restricted to 59 horses with large-colon SO that survived to hospital discharge or met the criteria specified for classification as nonsurvivors. Colonic luminal pressure in nonsurvivors (48.5 cm H2O; 34 to 80 cm H2O) was higher (P =.0001) than that measured in survivors (18 cm H2O; 2 to 50 cm H2O) of SO. From response operating characteristic curves, a luminal pressure of 38 cm H2O optimized the distribution of horses with SO into survivor and nonsurvivor groups. Sensitivity, specificity, and positive and negative predictive values for a colonic luminal pressure greater than 38 cm H2O in predicting nonsurvival were 0.89, 0.91, 0.72 and 0.97, respectively. Measurement of colonic luminal pressure may be useful for predicting survival in horses with colonic volvulus.