SummaryPostoperative complications and mortality can occur many weeks or months after colic surgery. We are interested in the long-term outcome of these cases. This study documents patterns of mortality and morbidity among 341 horses that recovered from colic surgery March 1998-August 2000. The progress of each horse was rigorously followed by periodic telephone and postal questionnaires. Event time data were recorded for each animal and a total of 321 horse years of survival, together with death from all causes, colic-related death and various postoperative complications.Postoperative survival (of all horses excluding grass sickness cases) was triphasic over the first 600 days and there was marked mortality in the first 10 days postoperatively. The probability of survival postoperatively decreased to 0.87 by 10 days, 0.82 by 100 days and declined slowly to 0.75 at 600 days. Horses suffering from epiploic foramen entrapment had a significantly reduced probability of postoperative survival (RR = 2.1, P = 0.033). The causes of death for 104 horses that died postoperatively and the prevalence of postoperative complications are recorded for the study population. Postoperative colic was the most prevalent complication with 100 horses (29%) suffering one or more episodes. However, only 16 horses (4.6%) suffered 3 or more episodes. The incidence of postoperative colic was 0.55 episodes/horse year at risk. This study provides data that will inform the prognosis for postoperative colic cases and identifies epiploic foramen entrapment as carrying a worse prognosis for survival than other strangulating lesions.

SummaryThe reason for u n d e rtaking this study was that postoperative complications of colic surgery lead to patient discomfort , p rolonged hospitalisation and increased cost. Potential risk factors for the 6 most common postoperative complications ( j u g u l a r t h rombosis, ileus, re -l a p a ro t o m y, wound suppuration, incisional herniation and colic) were evaluated using multivariable models. Jugular t h rombosis was associated significantly with heart rate gre a t e r than 60 beats/min and with i n c reased packed cell volume (PCV) at admission. The risk of postoperative ileus also increased with increasing PCV a t admission and was higher in horses recovering fro m pedunculated lipoma obstruction. Incisional herniation was s t rongly associated with wound suppuration and with i n c reasing heart rate at admission. The emergence of c a r d i o v a s c u l a r parameters as risk factors for s e v e r a l 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 s u ff e red epiploic foramen entrapment, are more than 4 times as likely to undergo re -l a p a rotomy than other horses. Horses that have suff e red postoperative ileus have a similarly increased risk of undergoing re -l a p a ro t o m y. The risk of postoperative colic is significantly associated with horses recovering from large colon torsion (>360°) and with having undergone re -l a p a ro t o m y. Hazard ratios (with 95% confidence intervals) for these last two e ffects are 3.1 (1.7, 5.7) and 3.4 (1.9, 6.2), re s p e c t i v e l y. 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.

We aimed to determine the effects of variations in dietary composition on equine gut microbiota and their fermentation products, and proposed that dietary modifications profoundly affect microbial ecosystems and their metabolites. Bacterial communities within the large intestine of three groups of horses were compared using oligonucleotide-RNA hybridisation methodology. Each group consisting of six horses was maintained on (1) a grass-only diet, (2) a concentrate diet (i.e. supplemented with hydrolysable carbohydrates) and (3) a concentrate diet but horses were affected by simple colonic obstruction and distension (SCOD), a prevalent form of dietary-induced intestinal disease. We show that in response to dietary change and intestinal disease, there is a progressive and significant increase in Lachnospiraceae, the Bacteroidetes assemblage and the lactic acid-producing, Bacillus -Lactobacillus -Streptococcus (BLS) group. In contrast, there is a corresponding decrease in the proportion of obligate fibrolytic, acid-intolerant bacteria, Fibrobacter and Ruminococcaceae. Assessment of monocarboxylic acids indicated that there are significantly higher concentrations of lactic acid in the colonic contents of horses maintained on a concentrate diet and those suffering from SCOD, correlating with the observed increase in the population abundance of the BLS group. However, the population size of the Veillonellaceae (lactate utilisers) remained constant in each study group. The inability of this group to respond to increased lactic acid may be a contributory factor to the build-up of lactic acid observed in horses fed a concentrate diet and those suffering from SCOD.

The risk of fatal distal limb fractures in thoroughbreds racing in the UK was calculated and shown to vary considerably between the different types of race. Flat turf racing was associated with the lowest risk (0.4 per 1000 starts) and national hunt flat racing was associated with the highest risk (2.2 per 1000 starts). The types of fracture were classified by detailed radiographic and postmortem examinations of all the cases recorded over two years, and the distribution of the different types of fracture in the five main types of racing was examined. Overall, lateral condylar fractures of the third metacarpus were the most common, and they were also the most common in national hunt-type races (hurdle, steeplechase and national hunt flat races). In all-weather flat racing biaxial proximal sesamoid fractures were most common, and in turf flat racing fractures of the first phalanx were most common. The risk of fractures of more than one bone was greater in national hunt-type races.

SummaryA case control study was performed to identify risk factors f o r colic caused by simple colonic obstruction and distension (SCOD) in the horse. Case horses were recruited from 2 v e t e r i n a ry school clinics. Control horses were population based and matched by time of year. A n u m b e r of risk factors w e re considered in the following areas: general care r a n d p remises information; exercise information; husbandry information (housing-and pasture -related); feeding information; breeding information; behavioural information; travel information; preventive medicine information and p revious medical information. All variables with a P value of <0.2 in the univariable analysis were considered for p o s s i b l e inclusion in a multivariable model. A final model, pro d u c e d by a forward stepwise method, identified crib-biting or windsucking, an increasing number of hours spent in a stable, a recent change in a re g u l a re x e rcise programme, the absence of administration of an ivermectin or m o x i d e c t i n anthelmintic in the previous 12 months and a history of travel in the previous 24 h as associated with a significantly i n c reased risk of SCOD. An alternative final model, pro d u c e d 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 y e a r the teeth were checked/treated as associated with a significantly increased risk of SCOD. T h ree 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. IntroductionPrevious epidemiological studies have identified risk factors associated with the development of colic in the horse (Tinker et al. 1994(Tinker et al. , 1997Cohen et al. 1995Cohen et al. , 1999Cohen and Peloso 1996;Reeves et al. 1996;Kaneene et al. 1997;Hillyer et al. 2001;Traub-Dargatz et al. 2001). In particular, they attempted to identify management or alterable risk factors, knowledge of which should allow a reduction in the colic incidence in the overall horse population. These previous studies have often produced conflicting results in respect of the impact of individual risk factors. This may be a result of differences in the study designs of the previous reports and their regional distribution (Reeves 1997). However, it has been suggested that differences may result from the use of equine colic, of any type, as a general disease outcome rather than a more specific diagnosis (Reeves et al. 1996). There has only been one recent epidemiological investigation of a specific colic diagnosis but this study compared the diagnosis of enterolithiasis with other cases of colic rather than the background horse population (Cohen et al. 2000). The aim of this study was to investigate risk factors in comparison to the general horse population for the occurrence of a more specific type of colic. Materi...