Outcome of horses with synovial structure involvement following solar foot penetrations in four UK veterinary hospitals: 95 cases.

REASONS FOR PERFORMING STUDY: The factors associated with outcome following solar foot penetration involving synovial structures treated using endoscopic lavage have not been described in the UK population. OBJECTIVES: To provide descriptive data on horses with synovial contamination or sepsis following solar penetration in 4 UK equine referral hospitals and to identify specific factors associated with the outcome. STUDY DESIGN: Retrospective case series. METHODS: Data were collected from 4 veterinary hospitals. Follow-up data were obtained via a telephone questionnaire. Two multivariable logistic regression models were generated. Model 1 included all horses with synovial contamination following foot penetration undergoing surgical treatment, with the outcome variable being euthanasia during hospitalisation. Model 2 included all horses surviving anaesthesia, with the outcome variable being failure to return to pre-injury athletic function. RESULTS: Ninety-five horses were included. Overall, 56% of horses survived to discharge and 36% of horses returned to pre-injury athletic function. Model 1 included penetration of the central frog sulcus (odds ratio [OR] 10, 95% confidence interval [CI] 1.9-51.8), concurrent distal phalanx involvement (OR 32, 95% CI 2.6-101.9), increasing days to presentation (OR 1.2, 95% CI 1.0-1.3) and hospital. Model 2 included increasing days to presentation (OR 1.1, 95% CI 1.1-1.6), breed (OR 32, 95% CI 2.2-135.4), more than one surgery (OR 5.6, 95% CI 1.0-32.7) and hospital. CONCLUSIONS AND POTENTIAL RELEVANCE: Synovial involvement following solar foot penetration has a guarded prognosis for survival to discharge and a poor prognosis for return to pre-injury athletic function. Penetration of the central sulcus of the frog and distal phalanx involvement are associated with euthanasia during hospitalisation. Delayed referral and hospitalisation are associated with both euthanasia and failure to return to pre-injury athletic function. Breed and more than one surgery are associated with failure to return to pre-injury athletic function. These data may assist veterinary surgeons and owners to make evidence-based decisions when managing cases with synovial involvement following solar foot penetration.

Risk factors for large colon volvulus in the UK.

REASONS FOR PERFORMING STUDY: Risk factors for large colon volvulus (LCV) in the horse have not been previously reported. Knowledge of these risk factors may allow the introduction of measures that could be taken to minimise the incidence of LCV. OBJECTIVES: To investigate risk factors for LCV in the horse. METHODS: A prospective, multicentre, unmatched case-control study was conducted over a 24 month period in the UK. Data on 69 cases and 204 control horses, from 4 veterinary hospitals, were obtained via telephone questionnaires. Multivariable logistic regression was used to identify associations between horse and management-level variables and the likelihood of LCV. RESULTS: Increasing height, multiple colic episodes in the previous 12 months and mares, with a greater odds ratio in mares that had previously foaled, were associated with increased risk of LCV. Receiving medication (excluding anthelmintic treatment) in the previous 7 days and quidding behaviour were also associated with increased risk. Management-level variables associated with greater risk of LCV were an increase in the hours of stabling in the previous 14 days, an increasing number of horses on the premises, and 3 or more people involved in the horse's care. Variables related to nutrition associated with increased risk of LCV were being fed hay, being fed sugar-beet, a change in pasture in the previous 28 days, and an alteration in the amount of forage fed in the last 7 days. CONCLUSIONS: This study has identified factors that may assist in the recognition of horses with increased risk of LCV and factors that might be altered to minimise the incidence of LCV. POTENTIAL RELEVANCE: Clinicians can use this information to identify horses at risk of LCV and to provide evidence-based advice to owners of these horses.

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.