G Mark Johnston

Dr. G Mark Johnston

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Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 August 2021 in Animals
Verified
Journal Article
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MGMiguel Gozalo-Marcilla
Miguel Gozalo-Marcilla
RBRegula Bettschart-Wolfensberger
Regula Bettschart-Wolfensberger
G Mark JohnstonG Mark Johnston
G Mark Johnston
Polly TaylorPolly Taylor
Polly Taylor
JRJosé Ignacio Redondo
José Ignacio Redondo
It is almost 20 years since the largest observational, multicentre study evaluating the risks of mortality associated with general anaesthesia in horses. We proposed an internet-based method to collect data (cleaned and analysed with R) in a multicentre, cohort, observational, analytical, longitudinal and prospective study to evaluate peri-operative equine mortality. The objective was to report the usefulness of the method, illustrated with the preliminary data, including outcomes for horses seven days after undergoing general anaesthesia and certain procedures using standing sedation. Within six months, data from 6701 procedures under general anaesthesia and 1955 standing sedations from 69 centres were collected. The results showed (i) the utility of the method; also, that (ii) the overall mortality rate for general anaesthesia within the seven-day outcome period was 1.0%. In horses undergoing procedures other than exploratory laparotomy for colic (“noncolics”), the rate was lower, 0.6%, and in “colics” it was higher, at 3.4%. For standing sedations, the overall mortality rate was 0.2%. Finally, (iii) we present some descriptive data that demonstrate new developments since the previous CEPEF2. In conclusion, horses clearly still die unexpectedly when undergoing procedures under general anaesthesia or standing sedation. Our method is suitable for case collection for future studies.
25 June 2025 in Animals
Verified
Journal Article
Open access
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HBHannah Boocock
Hannah Boocock
JFJana Flyps
Jana Flyps
AEAndré Escobar
André Escobar
JRJosé Ignacio Redondo
José Ignacio Redondo
Polly TaylorPolly Taylor
Polly Taylor
Rebekah SullivanRebekah Sullivan
Rebekah Sullivan
Equid anaesthetic mortality is of interest to practitioners. Data for donkey and hybrid mortality have not been specifically described. The main aim of this worldwide observational, prospective, multicentre cohort study was to report on mortality in the 7 days following a general anaesthetic or standing sedation in donkeys and hybrids. This study hypothesised that donkeys and hybrids would have higher mortalities compared to horses. Data were collected as part of the fourth Confidential Enquiry into Perioperative Equine Fatalities (CEPEF4). A total of 825 cases were included, with 757 donkeys and 68 hybrids. Overall, 616 donkeys and 56 hybrids underwent a general anaesthetic. The overall mortality rate for general anaesthesia in donkeys was 1.0% and 3.6% in hybrids. In total, 141 standing sedations were performed in donkeys and 12 in hybrids. Mortality rates for standing sedations were lower, with the donkey mortality rate as 0.7%, and no hybrid mortality was seen. The mortality for donkeys for general anaesthesia appeared similar to the horse, whilst hybrid mortality was higher. COLIC vs. NON-COLIC DEATHs and EUTHANASIAs were also examined in the study. Mortality for standing sedations was lower compared to general anaesthesia. However, the numbers are too low to draw definitive conclusions; further investigation is required.