The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2.

https://www.vmedtechnology.com/Post-surgical%20deaths.pdf

The risk of death: the confidential enquiry into perioperative small animal fatalities.

Background
The assessment of pain is critical for the welfare of horses, in particular when pain is induced by common management procedures such as castration. Existing pain assessment methods have several limitations, which reduce the applicability in everyday life. Assessment of facial expression changes, as a novel means of pain scoring, may offer numerous advantages and overcome some of these limitations. The objective of this study was to develop and validate a standardised pain scale based on facial expressions in horses (Horse Grimace Scale [HGS]).

/pdf/development-of-the-horse-grimace-scale-hgs-as-a-pain-39x1g65p9r.pdf

Development of the Horse Grimace Scale (HGS) as a pain assessment tool in horses undergoing routine castration.

A composite scale for assessing pain in dogs in a hospital setting has been developed on the basis of observations of their behaviour. Initially, 279 words and expressions suggested by 69 veterinary surgeons were reduced into 47 words and expressions which were allocated into seven behaviour categories: demeanour and response to people, posture, mobility, activity, response to touch, attention to painful area and vocalisation. Three statistical methods, hierarchical agglomerative cluster analysis, Cronbach's alpha coefficient, and analysis of variance with multiple comparisons and empirical cumulative distributions, were used to validate these procedures, and a questionnaire accompanied by a list of definitions was designed around the expressions. The new composite scale is more detailed than previously reported scales for assessing pain in dogs on the basis of their behaviour, and the methods used in its development are based on sound scientific principles.

Development of a behaviour-based scale to measure acute pain in dogs

https://www.wellbeingintlstudiesrepository.org/cgi/viewcontent.cgi?article=1068&context=acwp_arte

Defining and assessing animal pain

This chapter begins by providing an overview of current philosophies relevant to equine pain management. Objective and subjective techniques for assessing pain and the limitations of these are then described in depth. The conclusion emphasizes the need for an evidence based approach to managing pain in the horse and sets the stage for subsequent chapters in this edition.

https://www.vetequine.theclinics.com/article/S0749-0739(02)00009-3/pdf

Diagnosing and treating pain in the horse. Where are we today

Reasons for performing study Approximately 1 in 100 horses suffer unexpectedly from anaesthetic-related death. Identification and use of the safest anaesthetic drugs should support this aim. Experimental evidence has suggested that isoflurane should be a safer maintenance agent in equine anaesthesia than halothane. Hypothesis The death rate would be reduced in horses being maintained with isoflurane compared to halothane. Methods A multicentre randomised controlled trial was undertaken to compare the effects of isoflurane and halothane for maintenance of equine anaesthesia for all types of operation. Data were analysed from 8242 horses in which anaesthesia was maintained with either halothane or isoflurane using mixed effects logistic regression models. Results No overall benefit of either drug was detected. However, although not part of the primary hypothesis, data showed that the overall death rate was significantly reduced in horses age 2-5 years with isoflurane and that death from cardiac arrest was also reduced with isoflurane, particularly in high risk cases. Conclusions and potential relevance Halothane remains an acceptable anaesthetic for maintenance of anaesthesia in horses, but isoflurane may be safer in the young horse and in high risk cases.

Is isoflurane safer than halothane in equine anaesthesia? Results from a prospective multicentre randomised controlled trial.

Pharmacokinetics of morphine, buprenorphine and pethidine were determined in 10 cats. Six cats received morphine (0.2 mg/kg) intravenously and four intramuscularly. Five received buprenorphine (0.01 mg/kg) intravenously and six intramuscularly. Six received pethidine (5 mg/kg) intramuscularly. Jugular venous blood samples were collected at time points to 24 h, and plasma morphine concentrations were measured by high performance liquid chromatograpy (HPLC), buprenorphine by radioimmunoassay (RIA) and pethidine by gas chromatography. Our data for morphine show elimination half-life (t1/2el) 76.3 min intravenous (i.v.) and 93.6 min intramuscular (i.m.); mean residence time (MRT) 105.0 and 120.5 min; clearance (Clp) 24.1 and 13.9 mL/kg/min; and volume of distribution (V(dss)) 2.6 and 1.7 L/kg, respectively. Comparable data for buprenorphine are t1/2el 416.8 and 380.2 min; MRT 417.6 and 409.8 min; Clp 16.7 and 23.7 mL/kg/min; and V(dss) 7.1 and 8.9 L/kg. For i.m. pethidine, t1/2el 216.4 min; MRT 307.5 min; Clp 20.8 mL/kg/min and V(dss) 5.2 L/kg. For i.m. dosing, the tmax for morphine, buprenorphine and pethidine were 15, 3 and 10 min, respectively. The pharmacokinetics of the three opioids in cats are broadly comparable with those of the dog, although there is a suggestion that the cat may clear morphine more slowly.

Polly M Taylor

Papers

The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2.

Diagnosing and treating pain in the horse. Where are we today

Is isoflurane safer than halothane in equine anaesthesia? Results from a prospective multicentre randomised controlled trial.

Morphine, pethidine and buprenorphine disposition in the cat.

Investigation of the EEG effects of intravenous lidocaine during halothane anaesthesia in ponies