Search

Background: Keeping horses in open barns has positive effects on social interaction and free movement, which may improve horse welfare. However, many horse owners fear that housing in open barns leads to more injuries., Objective: To compare health events among horses housed in an active open barn (AOB) or in single boxes (BOX)., Study Design: A prospective study during 9 months and a 2-year retrospective study., Methods: Two housing systems in one farm were investigated: AOB and BOX in pairs or alone in paddock (2-4 h/day) using 66 and 69 horses in the prospective respectively retrospective study. Lameness, wounds, colic and days lost from training were recorded., Results: There were lower prevalences of lameness and colic in AOB than in BOX (18% vs. 26% and 0% vs. 5%; p < 0.001). Overall, there was a larger proportion of individuals with health events in AOB (83%) compared with BOX (52%) (p < 0.01). However, number of days lost to training did not differ between AOB (10 ± 15 days) and BOX (15 ± 34 days) (p = 0.36). There were no significant differences between the housing systems in number of health events/horse in the retrospective study: AOB 1.54 ± 1.51 versus BOX 1.14 ± 1.20 (p = 0.22)., Main Limitations: The different, not standardised, housing systems varied in size and number of horses with no individual consideration in this descriptive field study with no possibility to cross-over. A convenience sample was used., Conclusions: Lameness and colic were less frequent in the AOB system compared to single boxes, probably because the horses in the open barn could move freely day and night. Horses in AOB had a higher prevalence of wounds due to interactions between horses, but this did not lead to more days lost from training., (© 2024 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Reasons for Performing Study: Colic is an important health problem in managed horse populations. Currently, there is limited information about colic prevalence and risk factors for colic in working horse populations., Objectives: To determine the prevalence of, and risk factors for, colic in a working horse population in Egypt and to describe management practices in this working horse population., Study Design: Cross-sectional survey., Methods: Owners of 350 working horses were interviewed. Data about their horses, management and colic episodes in the preceding 12 months were collected. Dental examination was conducted on 342 horses and blood samples (n = 100) were collected for immunodiagnosis of tapeworm (Anoplocephala perfoliata) infection. Multivariable logistic regression analysis was used to identify risk factors for a history of colic in the preceding 12 months., Results: The 12-month prevalence of colic was 54.6%. Severe and moderate tapeworm infection intensity was identified in 3% and 26% of horses tested, respectively. Horses that had severe dental disease (odds ratio [OR] 6.8, 95% confidence interval [CI] 1.9-24.3, P<0.001), that displayed stereotypic behaviour (OR 2.0, 95% CI 1.15-3.5, P = 0.013), were fed ground corn during the 'dry season' (OR 1.65, 95% CI 1.03-2.6, P = 0.035) or that had received an anthelmintic in the previous 6 months (OR 2.1, 95% CI 1.3-3.3, P = 0.003) were more likely to have a history of colic in the preceding 12 months. Horses fed on rice bran during the 'green season' (OR 0.47, 95% CI 0.26-0.9, P = 0.015) and that displayed geophagia/coprophagia (OR 0.19, 95% CI 0.05-0.73, P = 0.001) were less likely to have a history of colic., Conclusions: Colic is common in this working horse population and this study has identified factors associated with altered likelihood of colic. The study provides important information that may be used to inform future prospective studies investigating colic in working horse populations and to assist development of preventive healthcare strategies. The Summary is available in Chinese - see Supporting information., (© 2016 EVJ Ltd.)

Reasons for Performing Study: Recurrent colic occurs frequently in the general horse population but little evidence exists about what factors place horses at greater risk of recurrent colic., Objectives: To quantify time-varying and non time-varying risk factors for recurrent colic among horses attended by first-opinion veterinary surgeons in northwest England., Study Design: Nested case-control study., Methods: A nested case-control study was conducted on data from a prospective longitudinal cohort study of 127 horses recruited subsequent to an episode of medical colic. Data were collected on management and recurrent colic episodes at 4-monthly intervals by telephone questionnaires. All recurrent colic episodes were selected as cases; controls were unmatched and randomly selected from all horse-time at risk. Data relating to the 30 days prior to the date of colic or control selection were used to determine exposure status. Multivariable logistic regression analyses were used to determine risk factors for recurrent colic., Results: In total, 59 cases and 177 controls were included. The final model showed that horses that displayed crib-biting/windsucking (odds ratio [OR] 10.1, 95% confidence interval [CI] 2.5-41.0) or weaving behaviour (OR 3.9, 95% CI 1.5-10.1) had an increased risk of recurrence of colic. Increasing time at pasture reduced the risk of recurrence (OR 0.99, 95% CI 0.99-1.0). A significant interaction was found suggesting that the risk associated with crib-biting/windsucking may be modified by feeding fruit/vegetables; however, further research is required before recommendations for feeding practices can be made., Conclusions: This study suggests that sufficient access to pasture may be an important means of reducing recurrent colic risk. The behavioural risk factors highlight individuals who may be at increased risk of recurrent colic and whose colic prevention strategies should be carefully managed., (© 2014 EVJ Ltd.)

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 chi2 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.

Reasons for Performing Study: Epiploic foramen entrapment (EFE) is a common cause of small intestinal strangulation in the horse and its epidemiology requires further investigation., Objectives: To identify horse- and management-level risk factors for EFE and to explore reasons for the apparent seasonality of this condition., Hypothesis: Horses exhibiting certain behaviours and those exposed to particular management practices that vary seasonally are at increased risk of EFE., Methods: A prospective unmatched, multicentre case-control study was conducted over 24 months in the UK. Data on 77 cases and 216 control horses were obtained from 9 collaborating clinics and logistic regression was used to identify associations between horse and management variables and the likelihood of EFE., Results: In a final multivariable model crib-biting/windsucking behaviour was associated with the largest increase in likelihood of EFE. A history of colic in the previous 12 months, increased stabling in the previous 28 days and height of the horse also increased the likelihood of EFE. Horses with access to a mineral/salt lick, those easily frightened and horses not fed at the same time as others were at reduced risk of EFE., Conclusions: Horses exhibiting certain behaviours, those with a previous history of colic and horses of greater height appear to be at inherently greater risk of EFE. The increase in likelihood of EFE with increased duration of stabling may explain the apparent seasonality of this condition.

Reason for Performing Study: Epiploic foramen entrapment (EFE) is one of the most common causes of small intestinal strangulation in the horse. Identification of risk factors would generate hypotheses about causation and may suggest preventive strategies., Hypothesis: Horses exhibiting certain behavioural patterns and those exposed to particular management practices are at increased risk of EFE., Methods: A matched case-control study was conducted on EFE cases admitted to hospitals in the UK, Ireland and USA. Data on 109 cases and 310 control horses were obtained by telephone questionnaire and conditional logistic regression was used to identify associations between horse- and management-level variables and the risk of EFE., Results: Crib-biting/windsucking behaviour was strongly associated with increased risk of EFE (OR 67.3, 95%CI 15.3-296.5). A history of colic in the previous 12 months (OR 4.4, 95%CI 1.5-12.7) and horses of greater height (OR/cm 1.05, 95%CI 1.01-1.08) were also at increased risk. The person(s) responsible for horses' daily care (nonowner/relative/spouse OR 5.5, 95%CI 2.3-13.3) and a number of behavioural features, including response to a stimulus causing fright (easily frightened OR 0.4, 95%CI 0.1-1.0) or excitement (sweats up easily/occasionally OR 0.3, 95%CI 0.1-0.8), reaction to their surroundings (inquisitive OR 0.4, 95%CI 0.2-0.8) and feeding behaviour when stressed (goes off food in full/part OR 0.3, 95%CI 0.1-1.0) were also associated with altered risk of EFE., Conclusions: The association between horses of greater height and those with a previous history of colic and increased risk of EFE suggests that some horses may be inherently predisposed to EFE. Furthermore, a behavioural pattern has been characterised that is common to horses at increased risk of EFE. Further research is required to investigate the causal pathway linking behavioural traits with gastrointestinal dysfunction and to determine whether behavioural modification reduces the risk of EFE., Potential Relevance: The findings of the present study have relevance to horses in the UK, Ireland and USA.

Reasons for Performing Study: Feeding concentrate has been putatively associated with risk of development of duodenitis-proximal jejunitis (DPJ); however, this association has not been evaluated systematically in a controlled study., Objectives: To determine whether there was evidence that feeding practices were associated with increased odds of developing DPJ employing a case control study., Hypothesis: The amount of concentrate fed daily to horses is significantly greater among horses that develop DPJ than control horses with either lameness or other types of colic., Methods: Feeding practices of cases of DPJ diagnosed between 1997 and 2003 were compared with those of 2 populations of control horses (colic controls and lameness controls) admitted to the clinic from the same time period. Following multiple imputation of missing data, comparisons were made using polytomous logistic regression., Results: Horses with DPJ were fed significantly more concentrate and were significantly more likely to have grazed pasture than either control populations; DPJ horses were significantly more likely to be female than were lameness horses. Results were unchanged after adjusting for bodyweight of the horse., Conclusions: Feeding and grazing practices differ among horses with DPJ relative to horses with other forms of colic and lame horses., Potential Relevance: The observed magnitudes of association were not sufficiently strong to merit diagnostic/predictive application; however, these observations, if substantiated by other studies, might provide important aetiological clues.

Reasons for Performing Study: There is little information on the prevalence of, and risk factors associated with, post anaesthetic colic (PAC) in horses undergoing nonabdominal operations., Objectives: To undertake the first prospective study of prevalence of PAC and identify risk factors in its development in nonabdominal procedures., Methods: A multicentre prospective case-control study was conducted, on every horse undergoing anaesthesia for a nonabdominal procedure between April 2004 and June 2005. Colic cases were defined as any horse with recognised signs of abdominal pain within 72 h of general anaesthesia that could not be attributed to any concurrent disease. Five control horses per case were selected randomly from the study population at all hospitals. Multivariable logistic regression analysis was used to examine the relationship between predictor variables and the risk of developing PAC., Results: The estimated mean prevalence of PAC in the study population was 5.2% (95% CI, 2.8, 8.0). However, the prevalence of colic varied between each centre. The most commonly diagnosed cause of colic was impaction. Multivariable analyses showed that the centre involved and the type of surgery performed were associated with an increased risk of PAC. Preoperative food deprivation and the use of opioid drugs were confounding factors., Conclusions: Prevalence of PAC varied significantly between the 4 hospitals studied; there may be hospital-related covariates that account for this. The type of surgery performed influenced the risk of PAC., Potential Relevance: Identifying the risk factors for PAC is a prerequisite for its prevention. This study indicates horses at increased risk of PAC that might benefit from a more critical evaluation of post anaesthetic gastrointestinal function and/or the provision of preventative measures. Further investigation is required to explain the variation in prevalence of PAC between centres.

Reason for Performing Study: Post anaesthetic colic is a recognised risk of general anaesthesia (GA), but causes are poorly understood., Objectives: To identify risk factors for development of colic following GA for magnetic resonance imaging (MRI) or nonabdominal surgery and to test whether the use of perianaesthetic morphine was associated with an increased risk of post anaesthetic colic., Methods: A total of 553 anaesthetic and clinical records of 500 horses anaesthetised at the Animal Health Trust were analysed, 342 (62%) involved MRI and 211 (38%) nonabdominal, predominantly orthopaedic surgery. Multivariable logistic regression analysis was used to examine the association between post anaesthetic colic and explanatory variables, including use of perianaesthetic morphine., Results: Twenty horses (3.6%) developed colic within 7 days of GA. A significantly larger (P = 0.001) proportion of the surgical cases developed post anaesthetic colic (7.1%) compared with MRI cases (1.5%). Having controlled for the effect of MRI/surgeon, there was evidence for a significantly increased risk of colic associated with maintenance of anaesthesia with isoflurane and administration of benzyl penicillin and/or ceftiofur. A reduction in risk of colic was associated with premedication with romifidine, longer duration of anaesthesia and sedation within 2 days of GA. Perianaesthetic morphine administration was not associated with increased risk., Conclusions: This study identified apparently novel risk factors for colic in horses following GA. Use of morphine was not found, after controlling for other MRI and surgery related risk factors, to be associated with an increased risk. The low prevalence of colic after GA and resulting low study power mean that further larger, multicentre collaborative studies are warranted to corroborate findings in this study., Potential Relevance: Better knowledge of risk factors should lead to achievable measures to reduce frequency of occurrence.

A case control study was performed to identify risk factors for colic caused by simple colonic obstruction and distension (SCOD) in the horse. Case horses were recruited from 2 veterinary school clinics. Control horses were population based and matched by time of year. A number of risk factors were considered in the following areas: general carer and premises information; exercise information; husbandry information (housing- and pasture-related); feeding information; breeding information; behavioural information; travel information; preventive medicine information and previous medical information. All variables with a P value of <0.2 in the univariable analysis were considered for possible inclusion in a multivariable model. A final model, produced by a forward stepwise method, identified crib-biting or windsucking, an increasing number of hours spent in a stable, a recent change in a regular exercise programme, the absence of administration of an ivermectin or moxidectin anthelmintic in the previous 12 months and a history of travel in the previous 24 h as associated with a significantly increased risk of SCOD. An alternative final model, produced by a backwards elimination method, identified the same variables as the forward model with, in addition, a history of residing on the current establishment for less than 6 months, a history of a previous colic episode and the fewer times per year the teeth were checked/treated as associated with a significantly increased risk of SCOD. Three of the risk factors in this model were associated with a large increase in risk: stabling for 24 h/day, crib-biting/windsucking and travel in the previous 24 h.

The reason for undertaking this study was that postoperative complications of colic surgery lead to patient discomfort, prolonged hospitalisation and increased cost. Potential risk factors for the 6 most common postoperative complications (jugular thrombosis, ileus, re-laparotomy, wound suppuration, incisional herniation and colic) were evaluated using multivariable models. Jugular thrombosis was associated significantly with heart rate greater than 60 beats/min and with increased packed cell volume (PCV) at admission. The risk of postoperative ileus also increased with increasing PCV at admission and was higher in horses recovering from pedunculated lipoma obstruction. Incisional herniation was strongly associated with wound suppuration and with increasing heart rate at admission. The emergence of cardiovascular parameters as risk factors for several postoperative complications is consistent with the hypothesis that endotoxaemia is important in the development of these complications. Early referral of colic cases, prior to the development of severe endotoxaemic shock, may minimise the risk of some postoperative complications. Horses that have suffered epiploic foramen entrapment, are more than 4 times as likely to undergo re-laparotomy than other horses. Horses that have suffered postoperative ileus have a similarly increased risk of undergoing re-laparotomy. The risk of postoperative colic is significantly associated with horses recovering from large colon torsion (>360 degrees) and with having undergone re-laparotomy. Hazard ratios (with 95% confidence intervals) for these last two effects are 3.1 (1.7, 5.7) and 3.4 (1.9, 6.2), respectively. Knowledge of the risk factors for postoperative complications allows more accurate prognostication postoperatively and suggests ways in which the risk of postoperative complications can be minimised.

The aim of this study was to estimate the incidence of colic in horses in Thoroughbred training premises in 1997 in the British Isles. The seasonal pattern and outcome of colic episodes were also investigated, together with any association between premises level variables and colic. Data were collected by a postal questionnaire. The results showed a colic incidence density of 7.19/100 horse years (s.e. 0.42) and a cumulative incidence of colic of 5.80% (s.e. 0.30). Premises were grouped according to whether they had more Flat than National Hunt horses (Flat premises) or more National Hunt than Flat horses (NH premises). A similar rate of colic episodes was found in each group. However, significantly higher cumulative incidences of one episode of colic were found in the Flat premises and of multiple episodes in the NH premises, respectively. The outcome of each episode of colic showed spontaneous recovery in 28.7%, medical recovery in 63.1%, surgical recovery in 2.0% and death in 6.2% of cases. This indicated an overall mortality rate from colic of 0.45 deaths/100 horse years. The seasonal pattern of episodes of colic showed a spring and autumn peak, with significant differences in the seasonal pattern between the Flat and NH premises. Relative risk analysis and logistic regression modelling with random effects showed significant associations between the number of episodes of colic and the number of horses on the premises (allowing for the number of horses on each premises, the larger premises had a decreased risk of colic). After adjusting for the number of horses, 3 other variables were associated with colic; Flat premises (with an increased risk), the owner being the sole person looking after the horses (a decreased risk) and the premises being a combined training and breeding establishment (a decreased risk).

The clinical features of 58 horses presenting with recurrent colic examined over a 5 year period were reviewed. The horses were categorised into 3 groups on the basis of the history of colic episodes. Recurrent transient colic Group 1 was characterised by 3 or more episodes of transient colic (of apparently similar type) occurring within one month. Recurrent transient colic Group 2 was characterised by 3 or more episodes of transient colic occurring within one year. Recurrent prolonged colic was characterised by 3 or more episodes of prolonged colic occurring within one year. Fifteen horses were classified as recurrent transient colic Group 1. This group had the highest mortality rate 53%. They included 3 horses with lymphosarcoma, 2 with intussusceptions, 2 with thromboembolic disease/verminous arteritis and 2 with partial ileal obstructions. The recurrent transient colic Group 2 comprised 27 cases with a mortality rate of 4%. Nine of these horses were affected by spasmodic colic. The recurrent prolonged group involved 16 horses with a mortality rate of 31%. These included 3 cases of recurrent colonic impaction and 2 cases each of lymphosarcoma, 2 thromboembolic disease, 2 partial ileal obstructions and 2 intestinal adhesions.

A prospective study of one year was conducted on 31 horse farms to obtain population based estimates of incidence, morbidity and mortality rates of equine colic. Farms with greater than 20 horses were enrolled by randomly selecting horse owners from 2 adjacent counties of Virginia and Maryland. Descriptive information for 1427 horses was collected at the initiation of the study and updated at 3 month intervals. Time on the farm during the study was tabulated for each horse. When colic was reported by the owner, investigators visited the farm to obtain information about the colic. The crude incidence density rate of colic was 10.6 colic cases/100 horse-years, based on 104 cases/358,991 horse-days. The median farm specific incidence density rate was 7 cases/100 horse-years, and the range for individual farms varied from 0 to 30 colic cases/100 horse-years. A specific diagnosis was not made for 84 (81%) of colic episodes. Seventy colic episodes (67%) were treated by a veterinarian. Drugs were used in 83 (80%) colic episodes, and 78 (75%) of colic cases were mild, requiring no treatment or resolving after only one treatment. Four horses required colic surgery. Fourteen (13%) horses had more than one episode of colic during the year. Mortality from all causes of death was 2.5 deaths/100 horse-years, mortality rate for colic was 0.7 deaths/100 horse-years. Proportional mortality rate of colic, 28%, was higher than for any other cause of death. Horses less than age 2 years or greater than age 10 years had lower incidence than horses age 2-10 years. No difference in colic risk between genders was identified. Arabian horses had the lowest and Thoroughbreds the highest breed specific incidence rates. Horses used for eventing, or in training had a statistically significant higher incidence rate of colic compared to mature horses with no use (pets, retired, on pasture with no stated purpose). Horses used for lessons or with no use had the lowest incidence rates.

A 1 year prospective study was conducted on 31 horse farms to identify risk factors for equine colic. Farms were randomly selected from a list from 2 adjacent counties of Virginia and Maryland, USA. The association between colic and farm or individual horse risk factors related to management, housing, pasture, use, nutrition, health and events was first examined by univariate statistical analysis. Individually significant (P < = 0.25 for farm factors, P < = 0.10 for horse factors) variables were used in a stepwise multivariable forward logistic regression to select explanatory factors (P < = 0.05). Analysis was conducted at 2 levels: farm and individual horse with farm specified as a random effects variable. No farm-level variables were significant. Significant horse-level variables included: age, odds ratio (OR) = 2.8 for horses age 2-10 years compared to < 2 years; history of previous colic, OR = 3.6 relative to no colic; changes in concentrate feeding during the year (1 per year, OR = 3.6, more than 1, OR = 2.2) relative to no changes; more than 1 change in hay feeding during the year, OR = 2.1 relative to no changes; feeding high levels of concentrate (> 2.5 kg/day dry matter, OR = 4.8, > 5 kg/day dry matter, OR = 6.3) relative to feeding no concentrate; and vaccination with monocytic ehrlichiosis vaccine during the study, OR = 2.0 relative to no vaccination. Feeding a whole grain with or without other concentrate components reduced risk, OR = 0.4, relative to feeding no whole grain. Results of the study suggest that diet and changes in diet are important risks for colic in a population of horses on farms.

Sixty-seven foals age < 150 days underwent a ventral celiotomy for colic. Of the 67 foals, 51 foals (82%) recovered from anaesthesia and 42 (63%) were subsequently released from the hospital. Three (6%) of the 51 foals were subjected to a repeat celiotomy. Long term follow-up was available on 36 foals. Twenty-nine (57%) of the 51 foals recovered from anaesthesia, were alive at least 2 years following surgery. Adhesions were identified in 8 (17%) of the foals which recovered from general anaesthesia but were subsequently subjected to euthanasia due to recurrent colic. Strangulating lesions were associated with a lower survival rate. Nineteen per cent of foals with strangulating intestinal lesions survived > 2 years following surgery, compared to 69% of foals with nonstrangulating lesions. The age of foals on admission had a significant effect on survival. Only 10% of foals less than 14 days of age survived, compared to 45.8% of foals between age 15 and 150 days.

A retrospective study of 75 cases of pedunculated lipoma obstruction (PLO) of the intestine was conducted. Age, breed and sex distributions were compared to the non-PLO colic population. Horses in the PLO group were significantly older than in the non-PLO colic group (P < 0.001). A significant increase in risk of PLO was associated with geldings (O.R. 2.32) and with ponies (O.R. 3.75). Of the 75 PLO cases analysed, 69 were strangulating, 70 involved small intestine and 5 involved small colon. Cases of strangulation obstruction tended to have lipomas originating distant to the mesenteric border of the intestine. The short-term survival rate for PLO cases was 48%. Long-term survival rate was 38%. Lipoma weight of some of the PLO group was compared with that from an asymptomatic pedunculated lipoma (APL) group. The two weight distributions were significantly different (P < 0.001).

The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other implications and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significantly under represented in the colic population. When compared with the control sample the number of spasmodic/undiagnosed colic cases in the 5-10-year-old group and the number of surgical colics in the over 15-year-old group were significantly greater than expected. No statistically significant correlation was found when the seasonal incidence of colic was compared with monthly temperature, change in monthly temperature, monthly rainfall, and rainfall weighted for temperature.