VN June 2023

Vetnuus | June 2023 6 This research was undertaken as part of the VRE module of the BVSc program. Dr Schliewert enlisted the Onderstepoort Veterinary Academic Hospital (OVAH) Equines Department to take part in the INCISE ( In ternational C olic S urg E ry) audit project in 2019, which was started by Professor Debra Archer of Liverpool University to set international benchmarks and identify prognostic factors relating to colic surgery outcomes. The study period was defined from 1 st January 2019 to 30 th September 2021. The data from hospital records were entered into the INCISE project’s website, which then generated an Excel spreadsheet used by the researcher to analyse the data. The project’s primary aim was to evaluate the outcomes of hospitalised horses via mortality rates. These were then compared to OVAH’s previously reported findings (as recorded in a previous study conducted by Voight from 1997-2007) ((Voigt et al., 2009). The secondary aim was to assess the potential value of various factors in prognostication. These factors included demographics, heart rate & packed cell volumes on initial presentation. A mixed linear model via StataCorp was used to ascertain statistical significance; a p - value < 0.05 was considered statistically significant. A total of 415 horses were presented during the study period. Forty horses were euthanised after initial assessment – in 60% of cases, surgical treatment was indicated, and 40% had medical treatment. In both situations, economic considerations were the main player in the decision for euthanasia but were a more prevalent factor when surgical treatment was indicated. Of those that received treatment, 292 were medically treated (77.8%), and 83 were surgically treated (22.1%) Of the 292 medically treated horses, 91% survived to discharge – 8 % euthanised during treatment (almost ¾ for welfare reasons due to poor prognosis), and 1% died during treatment. Of the 83 surgically treated horses, 87.7% survived to discharge. Of the 19 euthanasias, 11 horses were euthanised post-operatively, and eight were euthanised intra-operatively. In both scenarios, this decision was made mostly based on welfare concerns. When compared toVoigt’s study, there was approximately a 10% improvement in the overall survival rate (88% vs 78.8%) which is similar to the internationally published survival rates from Europe of 80-83% (Dybkjær et al., 2022, Boom and Sloet van Oldruitenborgh-Oosterbaan, 2018). The surgical survival rate markedly improved (77.1% vs 66.5%). The surgical survival rate is also comparable to international findings (54-85,5%)(Bjørn et al., 2014, Boom and Sloet van Oldruitenborgh-Oosterbaan, 2018, Mair and Smith, 2005a, Mezerova et al., 2008). The medical survival rate, previously quite high, also improved slightly (82,8% vs 91.1%). These figures are better than other international survival rates of 83-89,7% for medical treatment of colic (Boom and Sloet van Oldruitenborgh-Oosterbaan, 2018, Dybkjær et al., 2022). The most common presenting breeds were Thoroughbreds (41%), Warmbloods (29%) and Friesians (10%). Gender distribution was split evenly. Horses between 8-10 years old most frequently underwent surgery, with fewer older horses presenting. There was found to be no statistically significant effect of breed, gender, or age on the survival outcome of colicking horses (p = 0.890). This outcome corresponds with other retrospective studies. (Egenvall et al., 2008) As regards to heart rates (HR) on presentation, it was decided to categorise the data into “bradycardic” (<28bpm), “normal” (28-48bpm), “tachycardic” (48-69 bpm) and “shock”. The “Practical Guide to Equine Colic” by Southwood defines a HR over 70 bpm as indicative of Onderstepoort Colic surgery audit Main Author: Dr Lily van der Merwe Research Supervisor: Dr Tine Schliewert