Factor analysis of the interrelationships between clinical variables in horses with colic

A prospective survey of horses with colic referred to the Large Animal Hospital at the Royal Veterinary and Agricultural University of Copenhagen, Denmark, was undertaken between August 1994 and December 1997. The interrelationships between 17 clinical variables were analysed using factor analysis. Factor analysis uncovers the structure of the variability in data and therefore detects multicollinearity. A total of 528 horses were admitted in the study period. Of these, 16 were excluded from the analysis as a result of miscellaneous conditions. Only 205 horses had observations for all 17 variables. Because no major change occurred in the main diagnostic categories, this population was considered as a representative subset. Factor analysis confirmed the clinical impression of correlation between variables, but the multicollinearity turned out not to be strong. Four factors were extracted, and these accounted for 51% of the total variance. The retained factors were interpreted by integrating previously reported clinical research. The first factor, which was interpreted as endotoxaemia, had high loadings on capillary refill time, mucous-membrane colour, degree of pain, heart rate, packed-cell volume and abdominal sounds. In the second factor, cecal decompression, admission month and gastric reflux had the predominant influence, and this factor was explained as cecal tympany. The third factor was simply interpreted as age because it had high loadings on gender, age and temperature. In the fourth factor, the interpretation was not straightforward, although breed had the greatest influence in the formation of this factor. Subsequently, the extracted factors were used in a logistic-regression analysis to determine their association with outcome (survival/death). The two factors interpreted as endotoxaemia and age were related to the outcome.     

Electroencephalographic and cardiovascular variables as nociceptive indicators in isoflurane-anaesthetized horses

OBJECTIVE: To evaluate Fourier-transformed electroencephalographic (EEG) variables, mean arterial blood pressure (MAP) and pulse rate as nociceptive indicators in isoflurane-anaesthetized horses. ANIMALS: Five standardbred and three Norwegian cold-blooded trotter stallions undergoing castration, aged 2-4 years, mass 378-538 kg. MATERIALS AND METHODS: All horses received intravenous (IV) detomidine (10 microg kg(-1) IV) and butorphanol (0.01 mg kg(-1) IV). Additional detomidine (4 microg kg(-1) IV) was administered in the induction area. Anaesthesia was induced with ketamine (2.5 mg kg(-1) IV) and diazepam (40 microg kg(-1) IV), and maintained for 30 minutes with isoflurane (end-tidal concentration of 1.4%) vaporized in oxygen. The electroencephalogram, MAP and pulse rate were recorded for 15 minutes, beginning 5 minutes before skin incision. Differences between the mean values of recordings taken before, and during surgery were calculated and tested for significant differences using a two-sided Student's t-test. RESULTS: A significant rise in MAP and a fall in pulse rate were found. No significant change was found in any EEG variable. CONCLUSION/CLINICAL relevance Of the variables evaluated, MAP seems to be the most sensitive and reliable indicator of nociception in isoflurane-anaesthetized horses.     

Initial investigation of mortality rates and prognostic indicators in horses with colic in Israel: A retrospective study

Reasons for performing study: Initial assessment of the mortality rates and prognostic indicators in horses with colic presented to a referral hospital in Israel. Objectives: To determine mortality rates and to identify potential prognostic indicators in horses undergoing treatment for colic. Methods: The medical records of 208 colic cases were reviewed and mortality rates calculated including 95% confidence intervals. Mortality rates in surgical cases were calculated separately for strangulating and nonstrangulating lesions as well as for lesions of the large and small intestines. Potential prognostic indicators were identified and evaluated by Student's t test or X² test, where appropriate. Those found to be significant (P<0.05) were evaluated in 2 logistic regression models; one including all horses with colic and one for surgical cases only. Results: The overall mortality rate was 51/208 (25%); 5/72 (7%) in medically treated cases, 46/136 (34%) in surgical cases, 30/50 (60%) in strangulating lesions and 15/85 (18%) in nonstrangulating lesions, 17/27 (63%) in cases involving small intestinal lesions and 28/108 (26%) in cases with large intestinal lesions. Clinical parameters found to be significantly associated with death by univariate analysis were medical/surgical treatment, location of lesion, severity of lesion, mucous membrane colour (MM), capillary refill time (CRT) and heart rate. Using a multivariate logistic regression model, including all cases, medical/surgical treatment, CRT and MM were found to be prognostic indicators and when using the surgical cases alone, only CRT and lesion severity remained related to mortality. Conclusions: Mortality rates were similar or better than those previously reported in most cases, however, studies from the USA and the UK published better success rates for small intestinal surgeries. Cultural attitudes toward euthanasia may be associated with mortality rates. Potential relevance: These results assist clinicians in providing an immediate prognosis based on clinical findings at presentation and contribute to an international database that may aid future research in improving treatment of colic.     

Histologic findings in the gastrointestinal tract of horses with colic

Thirty horses were admitted to the University of Georgia Veterinary Medical Teaching Hospital with colic severe enough to warrant surgery and/or euthanasia. Gastrointestinal tracts of these 30 horses were histologically examined for morphologic changes. The horses were grouped according to cause of the colic (ie, simple obstruction, strangulation obstruction, thromboemboli, and inflammation). Lesions were graded as to severity, and grade scores were correlated with survival or nonsurvival. Mucosal changes developed distal and proximal to the primary lesion site and, although there were some differences between groups, changes characteristic of ischemia were common to all groups. The predictability of lesion grades of 2 or higher for nonsurvivability (90%) indicates that intestinal biopsy may have prognostic value in the postsurgical evaluation and management of equine colic.     

Prevalence and prognostic importance of hypomagnesemia and hypocalcemia in horses that have colic surgery

OBJECTIVE: To determine the prevalence of hypomagnesemia and hypocalcemia in horses with surgical colic. ANIMALS: 35 horses with surgically managed colic. PROCEDURE: Serum concentrations of total magnesium (tMg2+) and calcium (tCa2+), as well as ionized magnesium (iMg2+) and calcium (iCa2+) were analyzed before surgery and 1, 3, 5, and 7 days following surgery. A lead-II ECG and pertinent clinical data were also obtained at each time. RESULTS: Preoperative serum tMg2+ and iMg2+ concentrations were below the reference range in 6 (17%) and 19 (54%) horses, respectively. Serum concentrations of tCa2+ and iCa2+ were less than the reference range in 20 (57%) and 30 (86%) horses before surgery. Horses with strangulating lesions of the gastrointestinal tract had significantly lower preoperative serum concentrations of iMg2+ and iCa2+, as well as a higher heart rate than horses with nonstrangulating lesions. Horses that developed postoperative ileus had significantly lower serum concentrations of iMg2+ after surgery. Serum concentrations of magnesium and calcium (total and ionized) correlated significantly with the PR, QRS, QT, and corrected QT (QTc) intervals. Horses that were euthanatized at the time of surgery (n = 7) had significantly lower preoperative serum concentrations of iMg2+, compared with horses that survived. Neither serum magnesium nor calcium concentrations were predictors of hospitalization time or survival. CONCLUSIONS AND CLINICAL RELEVANCE: Hypomagnesemia and hypocalcemia were common during the perioperative period, particularly in horses with strangulating intestinal lesions and ileus. Serum concentrations of tMg2+ and tCa2+ were less sensitive than iMg2+ and iCa2+ in detecting horses with hypomagnesemia and hypocalcemia.     

Use of clinical pathology in evaluation of horses with colic

Clinical pathology is a valuable adjunct to physical examination of cases of colic. The present review considers evaluation of cases of colic for three main purposes: (1) making a prognosis, (2) deciding whether to operate, and (3) making a diagnosis. Blood tests noted to be useful for prognostication were hematocrit, lactate and urea nitrogen concentrations, pH, anion gap, fibrin/fibrinogen degradation products, antithrombin III activity, prothrombin time, and thrombin time. Horses with a poor prognosis often have relative polycythemia, marked lactic acidosis, high anion gap, azotemia, and coagulation abnormalities evidenced by increased fibrin/fibrinogen degradation products, decreased antithrombin III activity, and prolonged prothrombin and thrombin times. The decision to operate is usually a clinical one, supported by relative polycythemia, hyperglycemia, and, possibly, abnormal peritoneal fluid analysis. Diagnosis of the primary problem (causing the colicky signs) is also often based largely on physical examination. However, peritoneal fluid analysis provides worthwhile data, especially in cases of peritonitis or intestinal ischemia and infarction.     

Evaluation of plasma catecholamine and serum cortisol concentrations in horses with colic

OBJECTIVE: To evaluate plasma epinephrine and norepinephrine concentrations and serum cortisol concentration in horses with colic and assess the relationship of these variables with clinical signs, routinely measured clinicopathologic variables, and outcome in affected horses. DESIGN: Prospective observational study. ANIMALS: 35 horses with colic. PROCEDURE: Blood samples were collected within 30 minutes of arrival at the veterinary hospital from horses referred because of colic. Plasma and serum samples were analyzed for cortisol, epinephrine, norepinephrine, lactate, and electrolyte concentrations and acid-base variables. Heart rate at admission and outcome (survival or nonsurvival) were recorded. Univariate logistic regression was used to calculate crude (unadjusted) odds ratios and 95% confidence intervals. RESULTS: Of the 35 horses with colic, 26 survived. Higher plasma epinephrine, plasma lactate, and serum cortisol concentrations were significantly associated with increased risk of nonsurvival, but plasma norepinephrine concentration was not associated with outcome. Plasma epinephrine concentration was significantly correlated with heart rate (r = 0.68), plasma lactate concentration (r = 0.87), blood pH (r = -0.83), anion gap (r = 0.74), and base excess (r = -0.81). CONCLUSIONS AND CLINICAL RELEVANCE: The risk of death appears to be greater in colic-affected horses with high circulating concentrations of epinephrine and cortisol. The correlation of epinephrine with other biochemical markers of illness severity and with heart rate indicates that the degree of sympathetic activation in horses with colic can be inferred from routinely measured variables.     

Evaluation of activated neutrophils in the blood of horses with colic

OBJECTIVE: To evaluate the activation status of neutrophils in blood samples obtained from horses with naturally occurring colic associated with strangulating obstruction, nonstrangulating obstruction, or inflammatory bowel disease. ANIMALS: 30 horses with naturally occurring colic and 30 healthy control horses. PROCEDURE: Activation status of neutrophils was determined by assessing the number of neutrophils that could pass through filters with 5-microm pores, cell-surface CD11-CD18 expression, and alterations in size and granularity of neutrophils. RESULTS: Horses with impaction or gas colic did not have evidence of activated neutrophils. Horses with inflammatory bowel disease consistently had evidence of activated neutrophils, including decreased leukocyte deformability, increased CD11-CD18 expression, increased neutrophil size, and decreased neutrophil granularity. Horses with strangulating colic had variable results. Of horses with strangulating colic, 7 of 14 had marked changes in filtration pressures, 5 of 14 had increased CD11-CD18 expression, 6 of 14 had changes in neutrophil size, and 5 of 14 had changes in neutrophil granularity. Among horses with strangulating colic, changes in deformability, size, and granularity of neutrophils correlated with an adverse outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Activated neutrophils were detected in all horses with inflammatory bowel disease and a few horses with strangulating colic. Correlation of activated neutrophils with horses that had strangulating colic that died or were euthanatized indicates that activated neutrophils are a negative prognostic indicator. Additional studies are needed to determine whether activated neutrophils contribute directly to the adverse outcome in horses with strangulating colic.     

Examination of horses with acute colic: clinical and legal aspects

The article provides hands-on advice and scientific background information regarding the management of the equine acute colic patient. It summarizes essential information on the patient's history, clinical examination, and legal aspects. The scope of the history is based on the clinical appearance of the patient. In horses with violent and barely controllable signs of pain, it is limited to colic-associated information such as onset, course and severity of colic signs, and the last time of defecation, as well as prior therapeutic intervention. In these patients, the clinical examination is focussed primarily on the assessment of cardiovascular parameters, rectal temperature, and the patient's behaviour. The nasogastric intubation is an essential part of the examination of a horse with colic to prevent a gastric rupture due to gastric distension. Transrectal palpation is equally important and should always be performed unless there are important reasons to object to this procedure. In most cases, a thorough patient history and clinical examination of an acute colic patient allows the examining veterinarian to make a tentative diagnosis and a prognostic evaluation. This helps with the decision to start a conservative or a surgical therapy. Due to the existing obligatory documentation requirement and the duty to inform patient owners, it is of utmost importance to promptly document one's findings, therapeutic measures, consultations, and information of the patient owner in written form. This supports further therapy and it can also be of relevance in a potentially resulting lawsuit.     

Study of variables commonly used in examination of equine colic cases to assess prognostic value

In a retrospective study, the prognostic value and individual merit of seven variables, used in routine examination of colic cases, were tested. The following variables proved to be significant in discriminating between horses which survived and those which died: heart rate (P less than 0.00005), packed cell volume (P less than 0.00005) and intensity of colic signs (P less than 0.0001).     

Serum tumor necrosis factor activity in horses with colic attributable to gastrointestinal tract disease.

Over a 24-month period, serum tumor necrosis factor (TNF) activity was determined in 289 horses with colic attributable to gastrointestinal tract disease. Serum TNF activity was quantitated by use of a modified in vitro cytotoxicity bioassay, using WEHI 164 clone-13 murine fibrosarcoma cells. Causes for colic, determined by clinical and laboratory evaluation, exploratory celiotomy, or necropsy included: gastrointestinal tract rupture (GTR); ileal impaction; small intestinal strangulating obstruction (SIO); proximal enteritis (PE); transient small intestinal distention; large-colon displacement; large-colon volvulus; large-colon impaction; colitis; small-colon obstruction; peritonitis; and unknown. Each diagnosis was placed into 1 of 3 lesion categories: inflammatory disorders (GTR, PE, colitis, peritonitis); strangulating intestinal obstruction (SIO, large-colon volvulus); and nonstrangulating intestinal obstruction (ileal impaction, transient small intestinal distension, large-colon displacement, large-colon impaction, small-colon obstruction, unknown). The prevalence of high serum TNF activity and/or mortality were evaluated. Differences were tested at significance level of P less than 0.05. Approximately 20% of the 289 horses has serum TNF activity greater than that found in clinically normal horses (greater than 2.5 U/ml). Twenty-three horses (8%) had marked increase in serum TNF activity (greater than or equal to 10 U/ml) which was more prevalent among horses with SIO and PE than in horses of other diagnostic groups, except those with GTR. Mortality and marked increase in serum TNF activity were greater in horses with intestinal inflammatory disorders or strangulating intestinal obstruction than in horses with nonstrangulating intestinal obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Demographics and costs of colic in Swedish horses

BACKGROUND: Colic is an important cause of morbidity and mortality in horses. In Sweden, an insurance database with diagnostic medical information is maintained on >30% of the nation's horse population. HYPOTHESIS: The objective was to describe the occurrence of colic, defined by costly veterinary care and life claims, in horses at 1 insurance company during 1997-2002. HORSES: All horses (<21 years of age) with complete insurance for veterinary care and life during the period 1997-2002 were included. METHODS: Colic was defined as conditions where the main clinical sign was abdominal pain and the problem was related to the gastrointestinal system. The analyses included measures of incidence by sex, breed group, age categories, geographical location (urban/other), survival to and survival after colic, medical cost for colic, and multivariable modeling of risk factors related to the event of colic. RESULTS: In all, 116,288 horses contributed to 341,564 horse years at risk (HYAR). There were 3,100 horses with a colic diagnosis, of which 27% were settled for life insurance. The median gross cost for veterinary care was 4,729 Swedish Kronor (SEK). The overall occurrence and mortality rate of colic was 91 and 24 events per 10,000 HYAR. Survival after colic at 1 month was 76% (95% confidence interval: 75-78%). CONCLUSIONS AND CLINICAL IMPORTANCE: The occurrence of colic varied with breed group, age, and season. The mortality rates probably reflected the true mortality of colic. The veterinary care rates most likely underestimated of the risk colic because they represent relatively costly events.     

The usability of peritoneal lactate concentration as a prognostic marker in horses with severe colic admitted to a veterinary teaching hospital

Colic can be a life‐threatening condition in horses and there is a need for parameters that can help determine the prognosis and need for surgery. The aim of the study was to investigate whether peritoneal fluid (PF) lactate concentration is useful for this purpose in horses with severe colic presented to a veterinary hospital. During a 16 month period, the peritoneal fluid (PF) lactate concentration was measured in 74 of 760 colic horses admitted to the Utrecht University equine clinic using a portable analyser. When comparing survivors and nonsurvivors, heart rate, PF and blood lactate concentrations and blood glucose concentration were significantly higher in horses that did not survive. No horse with a PF lactate concentration >9.4 mmol/l survived. The presence of a strangulating lesion was also significantly associated with nonsurvival, as was PF colour: no horse with red PF survived in the present series. In horses with yellow PF, the blood glucose concentration was correlated with the presence of a strangulating intestinal lesion. Peritoneal lactate concentrations can be easily and rapidly measured using a portable analyser and may be useful in assessing the prognosis and/or need for surgery in equine colic cases.     

Use of plasma ionized calcium levels and Ca2+ substitution response patterns as prognostic parameters for ileus and survival in colic horses

OBJECTIVE: Hypocalcaemia is a common finding in horses with enterocolitis and severe gastrointestinal disorders. The aims of this study were to investigate in colic horses 1)the parameters related to hypocalcaemia, 2)the influence of hypocalcaemia on outcome and 3)the possible beneficial effect of Ca2+ substitution. DESIGN: Randomized controlled trial. SETTING: Intensive care unit. PATIENTS: One hundred forty-four horses that were admitted with an acute abdomen during a 1.5 year period were enrolled and daily evaluated for clinical criteria and whole blood ionized Ca2+ levels. Colic horses with hypocalcaemia were randomly assigned to receive Ca2+. INTERVENTIONS: Analysis of heparinised whole blood samples. Horses that were assigned to be treated received 400 mEq Ca2+ diluted in 10L of Ringer's lactate solution every 24 h until low reference range limits were obtained or until death. MEASUREMENTS AND MAIN RESULTS: 88% of all colic patients showed blood ionized Ca2+ levels below the reference range at the time of admission. Multivariable analysis revealed that the presence of reflux, signs of endotoxaemia, increased Packed Cell Volume (PCV), alkalinization of pH and the interaction PCV/pH all predispose colic horses to low ionized Ca2+ levels at the time of admission. The Odds for developing ileus during hospitalization are +/- 11.94 times larger for horses in the "very low" calcaemia interval, in comparison with normocalcaemic horses. The Odds for fatal outcome are respectively +/- 9.82 and 8.33 times larger for horses in the "very low" and "low" calcaemia interval. Ca2+ substitution increased the probability of survival, provided that Ca2+ levels could be normalized. The lack of an upward calcaemia response, despite repetitive Ca2+ substitutions, can be guarded as a poor ominous sign. CONCLUSIONS: Hypocalcaemia in colic horses is of prognostic relevance both with regard to survival as to the probability of development of ileus during hospitalization. This study shows the importance of routine measurement of ionized calcium levels in colic horses. Moreover, correction of hypocalcaemia seems to improve clinical outcome.     

Cardiac arrhythmias and electrolyte disturbances in colic horses

Background

Despite increased focus on cardiac arrhythmias in horses, the nature and prevalence is still poorly described. Case reports suggest that arrhythmias occurring secondary to systemic disease are seen more commonly in the clinic than arrhythmias caused by cardiac disease. The aim of this study was to investigate the prevalence of arrhythmias in colic horses referred for hospital treatment. Associations between electrolyte disturbances and arrhythmias were also investigated.The study population consisted of eight control horses and 22 referred colic horses. A Holter electrocardiography (ECG) was recorded during the first 24 hours of admission. The ECG’s were analysed by a software program followed by manual visual inspection. Arrhythmias registered included second degree atrioventricular (AV) blocks, supraventricular premature complexes (SVPCs), and ventricular premature complexes (VPCs). Blood was collected at admission and again between 12 and 24 hours after ECG was applied, and analysed for concentrations of potassium, sodium, ionised calcium, chloride, glucose, and L-lactate.

Results

Heart rate was 37.4 ± 3.7 bpm in the control group, and 51.6 ± 11.8 bpm, in the colic group, which was significantly different (P < 0.0001). AV blocks and SVPCs were found in both groups, however only colic horses showed VPCs. No significant difference between the two groups was found for AV blocks, SVPCs, and VPCs (P = 0.08 - 0.76). The mean levels of potassium, sodium, ionized calcium, and chloride were significantly lower in the colic group compared to the control group at admission. Mean levels of glucose and L-lactate were significantly elevated in the colic group (P < 0.05).

Conclusions

This study describes prevalence of cardiac arrhythmias and electrolytes concentrations in colic horses compared to healthy controls. Although we only observed VPCs in the colic horses, no significant differences between colic horses and controls were found. Despite the colic horses having electrolyte changes at admission no correlation was found between the electrolyte disturbances and cardiac arrhythmias. Although no clear conclusions can be drawn from the present study, the results indicate that relatively mild colic per se is not pro-arrhythmogenic, whereas severe colic probably are more likely to result in ventricular arrhythmia.     

Causes of gastrointestinal colic in horses in western Canada: 604 cases (1992 to 2002)

The medical records of equine gastrointestinal colic cases presented to the Western College of Veterinary Medicine between 1992 and 2002 are reviewed. There was no breed predisposition to colic. Geldings were more prone to colic than females and stallions. Overall, the 3 most common causes of colic were large colon impaction (20.8%), large colon displacement (16.5%), and spasmodic colic (11.7%), after excluding the 13% of cases in which the diagnosis was undetermined. Of the medical cases, large colon impaction (38.4%) and spasmodic colic (22.5%) were the most common. Of the surgical cases, large colon displacement (24.5%), large colon torsion (14.3%), and strangulating lipoma (13.5%) were the most common. Recovery rate for the medical cases was 93.6%. Recovery rate for surgical cases was 73.5%. In conclusion, most of the equine colic cases were medical, and the recovery rates for both surgical and medical cases were comparable with those of other studies.     

Use of plasma ionized calcium levels and Ca(2+) substitution response patterns as prognostic parameters for ileus and survival in colic horses

Summary Objective: Hypocalcaemia is a common finding in horses with enterocolitis and severe gastrointestinal disorders. The aims of this study were to investigate in colic horses (!))the parameters related to hypocalcaemia, (2))the influence of hypocalcaemia on outcome and (3))the possible beneficial effect of Ca(2+ )substitution. Design: Randomized controlled trial. Setting: Intensive care unit. Patients: One hundred forty-four horses that were admitted with an acute abdomen during a 1.5 year period were enrolled and daily evaluated for clinical criteria and whole blood ionized Ca levels. Colic horses with hypocalcaemia were randomly assigned to receive Ca(2+). Interventions: Analysis of heparinised whole blood samples. Horses that were assigned to be treated received 400 mEq Ca(2+) diluted in 10L of Ringer's lactate solution every 24 h until low reference range limits were obtained or until death. Measurements and main results: 88% of all colic patients showed blood ionized Ca levels below the reference range at the time of admission. Multivariable analysis revealed that the presence of reflux signs of endotoxaemia increased Packed Cell Volume (PCV) alkalinization of pH and the interaction PCV/pH all predispose colic horses to low ionized Ca(2+) levels at the time of admission. The Odds for developing ileus during hospitalization are ± 11.94 times larger for horses in the "very low" calcaemia interval in comparison with normocalcaemic horses. The Odds for fatal outcome are respectively ± 9.82 and 8.33 times larger for horses in the "very low" and "low" calcaemia interval. Ca(2+) substitution increased the probability of survival provided that Ca(2+) levels could be normalized. The lack of an upward calcaemia response despite repetitive Ca(2+) substitutions can be guarded as a poor ominous sign. Conclusions: Hypocalcaemia in colic horses is of prognostic relevance both with regard to survival as to the probability of development of ileus during hospitalization. This study shows the importance of routine measurement of ionized calcium levels in colic horses. Moreover correction of hypocalcaemia seems to improve clinical outcome.     

Risk factors of colic in horses in Austria

A hospital‐based case study was conducted at the University of Veterinary Medicine Vienna for a 1‐year period. The purpose of this study was to determine possible alterable and non‐alterable risk factors of equine colic in Austria. The investigated parameters were obtained from hospital medical records (individual factors, duty of the horse, deworming, change in diet and water intake), from questionnaires (feed intake, watering types, housing and pasture practices) and from http://www.orf.at (weather‐related factors). Moreover, 221 collected feed samples were investigated through hygienic quality sensory evaluation and mould, yeast and bacteria presumptive samples were confirmed by microbiological investigation. Variables that were observed from the hospital medical records and found to be significantly associated with colic in a univariate analysis were included in multivariate analysis and the only remaining risk factor was decreased water consumption (p < 0.001, OR = 5.025). Consequently, a total of 2743 horses and 366 cases of colic were observed during the study period. The risk factors for colic in Austria were identified for the first time in this study and these increased risk factors were decreased water consumption, high amount of concentrate intake (p = 0.037), low hygienic quality of hay (p = 0.027) and high temperature on the arrival date (p = 0.003). Results suggest that the occurence of colic may not stop, but may decrease with better feed management practices in Austria.