Cardiorespiratory and endocrine effects of endogenous opioid antagonism by naloxone in ponies anaesthetised with halothane

Reduction of the olfactory cognitive ability in horses during preslaughter: stress-related hormones evaluation

As horses may perceive several odour signals of danger at slaughter, application of mentholated ointment to their nostrils may limit their perception of danger. To assess the effect of the application of a mentholated ointment to horse nostrils on the stress response during pre-slaughter handling, plasma levels were evaluated for cortisol, beta-endorphin, epinephrine and norepinephrine prior to and after stunning. Twenty draught-type horses were divided into control (n=10) and treated (n=10) groups and a mentholated ointment applied to the nostrils of the treated horses following blood sampling in lairage 45 min prior to slaughter. Treatment did not affect plasma concentrations of beta-endorphin or cortisol but significantly reduced the concentrations of epinephrine and norepinephrine observed in post-stun plasma. These results indicated that mentholated ointment applied to the nostrils of horses pre-slaughter reduced their adrenergic response to the slaughter environment, implying that the stress response may be reduced with this technology.

Anesthesia in Caspian ponies

OBJECTIVE

To evaluate some of the clinical and laboratory parameters following diazepam-acepromazine, thiopental, and halothane anesthesia in Caspian ponies.

STUDY DESIGN

Prospective experimental trial.

ANIMALS

Six healthy Caspian ponies of both sexes, aged 11 +/- 3 years and weighing 318 +/- 71 kg.

METHODS

The ponies were pre-medicated with diazepam (0.2 mg kg(-1)) and acepromazine (0.05 mg kg(-1)) IV. Sodium thiopental 5% was administered IV, 10 minutes later and anesthesia was maintained with halothane in oxygen for 1 hour. Heart and respiratory rates, mean arterial blood pressure, cardiac rhythm, and signs of anesthetic depth were monitored during anesthesia. Hematological and serum biochemical parameters were evaluated before anesthesia and at 1, 2, 3, 24, 48, 72, and 96 hours. Urine specific gravity and cytology were evaluated at the same intervals following anesthesia. Parametric data were analyzed using repeated measures anova.

RESULTS

Considerable sedation/tranquilization without excitement was achieved following pre-medication. Heart rate significantly increased and mild hypotension occurred during anesthesia. Sinus arrhythmia and second degree AV block occurred in five horses. Respiratory rate decreased during anesthesia, with an accompanying respiratory acidosis. Body temperature also decreased. Recovery was scored 'good' in four horses and 'satisfactory' in the other two. Blood urea nitrogen concentration was significantly increased at 1-3 hours post-anesthesia. Blood glucose was significantly increased at 48, 72, and 96 hours, and creatine kinase and aspartate aminotransferase were significantly increased at 24 and 48 hours post-anesthesia.

CONCLUSION AND CLINICAL RELEVANCE

This simple anesthetic protocol can be used in Caspian ponies and an acceptable anesthetic with a reasonable recovery can be expected.

Endogenous opiates and behavior: 2001

This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).