Survival of horses following strangulating large colon volvulus

Reasons for performing study: The pattern of long‐term survival and specific factors associated with long‐term survival have not previously been evaluated in horses with a strangulating large colon volvulus (LCV). Objectives: To provide data on the long‐term survival of horses with LCV and to identify pre‐, intra‐ and post operative variables associated with survival. Methods: Clinical data and long‐term follow‐up information were obtained from 116 horses with a strangulating LCV (≥360°) undergoing general anaesthesia. Two multivariable Cox proportional hazards models for post operative survival time were developed: Model 1 included all horses and evaluated preoperative variables and Model 2 included horses that survived anaesthesia and evaluated pre‐, intra‐ and post operative variables. Results: The study population comprised 116 horses. Eighty‐nine (76.7%) survived general anaesthesia. Of these, the percentage that survived until discharge, to one year and to 2 years was 70.7%, 48.3% and 33.7%, respectively. Median survival time for horses that survived general anaesthesia was 365 days. In Model 1 increased preoperative packed cell volume (PCV) was significantly associated with reduced post operative survival (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.05–1.11). However, this effect changed over time. In Model 2 abnormal serosal colour intraoperatively (HR 3.61, 95% CI 1.55–8.44), increased heart rate at 48 h post surgery (HR 1.04, 95% CI 1.02–1.06), and colic during post operative hospitalisation (HR 2.63, 95% CI 1.00–6.95), were all significantly associated with reduced post operative survival. Conclusions: Survival time in horses with a LCV was associated with preoperative PCV, serosal colour, heart rate at 48 h post operatively and colic during post operative hospitalisation. Potential relevance: This study provides evidence‐based information on the long‐term survival of horses with LCV and identifies parameters that may assist decision‐making by clinicians and owners.     

Primary gastric impaction in horses: A retrospective study of 20 cases (2005–2008)

Primary gastric impaction is an uncommon condition. Furthermore, the factors associated with gastric impaction and the optimal method of treatment are not clear. The aim of this article is to describe the clinical findings, treatment and outcome of horses with a primary gastric impaction. Medical records of horses that presented with a primary gastric impaction between 2005 and 2008 were reviewed and 20 horses with a primary gastric impaction identified. Diagnosis of a primary gastric impaction was made if the horse had been fasted for a minimum of 16 h, a concretion of ingesta precluded visualisation of the margo plicatus and there was no evidence of concurrent intestinal pathology. Thirteen of 20 (65%) horses were presented on an emergency basis. The most common complaint was inappetence (50%) followed by acute colic (35%) and recurrent colic (35%). On initial examination for colic, all horses had a normal heart rate and 7 of 20 (35%) had decreased gastrointestinal borborygmi. All horses were treated with enteral fluid therapy. The median dose of fluids administered per day was 5 doses (range 1–8 doses) of 2–10 l of isotonic electrolyte solution. The median length of treatment until resolution was 2 days (range 1–5 days). Eighteen of 20 (90%) horses survived to discharge. Primary gastric impaction appears to be a condition with clinical signs of inappetence and mild abdominal discomfort. This is the largest group of horses reported that were treated with enteral fluid therapy for a gastric impaction and it was concluded that enteral fluid therapy was of value in this study.     

Small intestinal volvulus in 115 horses: 1988-2000

OBJECTIVE: To evaluate the historical data, signalment, clinical signs, results of laboratory analyses, treatment, and outcome of horses with small intestinal (SI) volvulus. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: One hundred and fifteen client-owned horses, aged 1 month to 21 years. METHODS: Clinical signs, laboratory data, surgical or necropsy findings, and outcome for horses with SI volvulus were obtained from medical records, identified by computer search and manual review. RESULTS: There was no statistical difference in signalment between cases and the hospital population. Seventy-four percent of horses were >/=3 years. There were considerable variations in clinical signs on admission; high heart rate and signs of severe pain were not consistent features. Examination per rectum identified distended small intestine in only 69% of horses. One hundred horses had surgery, and small intestine resection was performed in 25. Eighty-four horses were recovered from surgery, and 67 horses survived to hospital discharge (80% of horses recovered from surgery, 58% of 115 horses). Forty-eight percent that were ultimately discharged had a post-operative complication and these horses had a longer average stay than horses with no complication (11 days versus 8.9 days). CONCLUSIONS: We identified 115 horses with primary SI volvulus over a 12-year period. We found that the population of horses with this lesion was older than has previously been reported and that the prognosis for post-operative survival to hospital discharge is good (80%). Post-operative complications were common, and affected approximately half the horses that were ultimately discharged from the hospital. CLINICAL RELEVANCE: This information may aid diagnosis and prognosis and guide decision making for horses with this condition.     

Duodenal volvulus as a cause of gastric rupture in a 15‐year‐old Warmblood gelding

Duodenal volvulus is an unreported cause of colic in the horse. This case report describes a 15‐year‐old Warmblood gelding evaluated for acute abdominal discomfort. Exploratory celiotomy revealed duodenal volvulus and gastric rupture resulting in severe, acute, septic peritonitis. To the authors' knowledge, this is the first report of a volvulus of the equine duodenum.     

Factors associated with mortality and morbidity in small intestinal volvulus in horses

OBJECTIVE: To determine historical, physical, and clinical factors that may affect morbidity and mortality in horses with small intestinal volvulus unrelated to other causes (e.g., incarceration, lipoma, etc.). STUDY DESIGN: Retrospective study. ANIMALS: Client-owned horses (115), aged 1 month to 21 years. Methods: Data were obtained from medical records, identified by computer search and manual review. Continuous variables were compared between affected and non-affected horses with Mann-Whitney U-tests and non-continuous variables with Fisher's exact test (2 x 2 tables) or chi(2)-tests (larger tables). Stepwise logistic regression analysis was used to develop a multivariable model of the risk factors, taking account of confounding and interaction. RESULTS: Eighty percent of horses recovered from surgery survived to hospital discharge. Neither age, breed, nor sex was related to mortality. Survivors had a significantly lower heart rate, shorter capillary refill time, and better mucous membrane color. Variables associated with worsening cardiovascular status, increased hemoconcentration, and exudation of cells and protein into peritoneal fluid were significantly associated with non-survival. After recovery from surgery, the most serious complication was colic, which was significantly associated with non-survival (P=.028) as was a second celiotomy (P<.01). Both of these complications were associated with a jejunocecostomy during the first surgery. CONCLUSIONS: Significant differences in the clinical and clinicopathologic signs were identified between survivors and non-survivors. CLINICAL RELEVANCE: These findings can be used to make a scientific assessment of prognosis in the pre-operative, operative, and post-operative management of horses with small intestinal volvulus.     

Use of ultrasound to evaluate outcome following colic surgery for equine large colon volvulus

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.     

Coagulation profiles in 27 horses with large colon volvulus

Objective: The objective of this study was to evaluate coagulation profiles in horses with surgical treatment of large colon volvulus (LCV), and determine if an association exists between hemostatic dysfunction and outcome. Design: Prospective clinical investigation from February to December 2000. Setting: Large animal intensive care unit in a veterinary teaching hospital. Interventions: Blood was collected from horses intra‐operatively, 24, and 48 hours following surgical treatment for LCV. Measurements: Coagulation profiles, thrombin–antithrombin (TAT) levels, and D‐dimer concentrations were determined for each time point. The number of tests abnormal in the standard coagulation profile, defined as the degree of hemostatic dysfunction, was determined for each horse for the duration of the study period. The association between each test and outcome, as well as the degree of hemostatic dysfunction for each horse and outcome, was determined using univariate analysis and logistic regression. TAT levels and D‐dimer concentrations were compared to the results of the standard coagulation profile and to patient outcome using univariate analysis and logistic regression. Main results: Seventy percent of horses evaluated with surgical treatment of LCV had evidence of hemostatic dysfunction (3/6 tests abnormal). Only 18% of those patients had clinical signs recognized by the attending clinician as a coagulopathy. There was an association between the development of a coagulopathy and outcome, with horses with 4/6 tests abnormal being more likely to be euthanized, and those with 3/6 tests abnormal having a prolonged hospital stay. Platelet count, prothrombin time, and TAT levels may be helpful in predicting outcome in horses with LCV. Conclusions: Hemostatic function should be evaluated in horses with surgical treatment of LCV to detect subclinical coagulopathies and direct subsequent intervention.     

Diagnosis,management and prognosis of large colon impactions

The majority of large colon feed impactions occur in the left ventral colon at the pelvic flexure. Sand and enterolith impactions most commonly occur in the left ventral colon at the pelvic flexure or in the right dorsal colon; however, sand can accumulate anywhere along the gastrointestinal tract. Enteral fluid therapy can, in most cases, supplement or even replace i.v. administration of fluids and it appears effective and safe to soften large colon contents and resolve simple large colon impactions. Surgical intervention is indicated when a concurrent displacement is suspected, as lengthy medical treatment of large colon impaction secondary to large colon displacements would not be indicated and may increase the risk of colonic rupture. Other indications for surgical intervention include uncontrollable pain, when cardiovascular parameters deteriorate, or when there is evidence of intestinal devitalisation. The prognosis for horses undergoing large colon enterotomy is dependent on the extent and type of impaction, but is generally excellent.     

Outcome and long‐term follow‐up of 20 horses undergoing surgery for caecal impaction: A retrospective study (2000–2008)

Reasons for performing study: If untreated, caecal impaction may progress to rupture of the caecum and reports of long‐term outcome for horses undergoing surgery for caecal impaction are required. Objectives: To describe short‐ and long‐term complication rates for horses undergoing surgery for caecal impaction in an otherwise life‐threatening gastrointestinal condition. Methods: Case records were reviewed for horses undergoing surgery for caecal impaction. Horses were included in the study if an abnormally large, fluid‐distended or feed‐impacted caecum was the primary diagnosis at surgery and excluded if the caecum had already ruptured upon opening the abdomen, necessitating euthanasia. Short‐term follow‐up data were obtained from clinical records; and included complications, repeat celiotomy and survival to discharge. Long‐term survival was defined as survival for >1 year post operatively. Long‐term follow‐up data were obtained through telephone interviews with owners and referring veterinary surgeons. Survival, occurrence of post operative colic and subsequent use of the horse were recorded. Results: Twenty horses underwent surgery for caecal impaction: 16 horses underwent caecal bypass (typhlotomy and removal of caecal contents, ileal transection followed by ileocolostomy); 3 underwent typhlotomy alone; and one horse underwent typhlotomy followed by a second procedure where caecal bypass was performed. Five horses (25%) were admitted for colic evaluation with primary caecal impactions, in 10/20 (50%) of cases the impaction was secondary to previous orthopaedic surgery and in 5/20 (25%) caecal impaction was identified at repeat celiotomy following a previous colic surgery. Sixty‐five percent (13/20) of horses survived to discharge; 11/13 (85%) of horses discharged survived long term; 100% (3/3) horses that received typhlotomy alone were discharged and survived long term. Conclusions: The prognosis following caecal impaction surgery is fair, if the horse survives to discharge then prognosis for long‐term survival is good. Potential relevance: Surgery for caecal impaction carries a fair prognosis for a potentially life threatening disease, in particular where caecal dysfunction is suspected.     

Complete caecal bypass without ileal transection for caecal impaction in horses: seven clinical cases (1997-2007)

Objectives To report the clinical outcome in seven horses following use of a newly described surgical technique for treating caecal impaction. Methods The medical records of seven horses with caecal impaction treated surgically using a stapling technique to create a complete caecal bypass without ileal transection were reviewed. Data were obtained from the records and through telephone interviews with case-associated personnel. Results The mean age was 10 years (range 2–22 years) and duration of colic ranged from 24 h to 2 weeks. Five horses had type II motility dysfunction and the remaining two had type I. Mean surgical time was 185 min (range 146–245 min) and the horses were hospitalised for a mean of 12.4 days (range 9–22 days); 71% (5/7) were discharged from hospital and all five were alive 60 days from the surgery date. One horse was lost to follow-up. The four (66.7%) available remaining horses were alive ≥ 1 year (long-term survivors). Conclusions Complete caecal bypass without ileal transection for clinical cases of caecal impaction had comparable outcomes to complete bypass with ileal transection. The technique is easy to perform, has the potential to reduce surgical time, compared with traditional bypass techniques, and may reduce the risk of intraoperative abdominal contamination. It is recommended for use in clinical cases in which caecal bypass is desirable.     

Colonic volvulus with defects of the mesenteric attachments in a yearling Friesian colt

This report describes an unusual case of colonic volvulus associated with multiple mesenteric abnormalities. A yearling Friesian colt presented with signs of colic that persisted despite analgesia. The colt showed signs of circulatory compromise and had abnormal findings on rectal palpation. An exploratory laparotomy was performed. A complete volvulus of the ascending colon was identified associated with multiple mesenteric anomalies of unknown aetiology. The colt was subjected to euthanasia due to the extent of the intestinal damage and the likelihood of recurrence. The authors speculate that the anomalies may have been of genetic aetiology associated with a restricted gene pool.