A comparison of traditional and quantitative analysis of acid-base and electrolyte imbalances in horses with gastrointestinal disorders

The purpose of this study was to compare traditional and quantitative approaches in analysis of the acid-base and electrolyte imbalances in horses with acute gastrointestinal disorders. Venous blood samples were collected from 115 colic horses, and from 45 control animals. Horses with colic were grouped according to the clinical diagnosis into 4 categories: obstructive, ischemic, inflammatory, and diarrheic problems. Plasma electrolytes, total protein, albumin, pH, pCO2, tCO2, HCO3-, base excess, anion gap, measured strong ion difference (SIDm), nonvolatile weak buffers (A(tot)), and strong ion gap were determined in all samples. All colic horses revealed a mild but statistically significant decrease in iCa2+ concentration. Potassium levels were mildly but significantly decreased in horses with colic, except in those within the inflammatory group. Additionally, the diarrheic group revealed a mild but significant decrease in Na+, tCa, tMg, total protein, albumin, SIDm, and A(tot). Although pH was not severely altered in any colic group, 26% of the horses in the obstructive group, 74% in the ischemic group, 87% in the inflammatory group, and 22% in the diarrheic group had a metabolic imbalance. In contrast, when using the quantitative approach, 78% of the diarrheic horses revealed a metabolic imbalance consisting mainly of a strong ion acidosis and nonvolatile buffer ion alkalosis. In conclusion, mild acid-base and electrolyte disturbances were observed in horses with gastrointestinal disorders. However, the quantitative approach should be used in these animals, especially when strong ion imbalances and hypoproteinemia are detected, so that abnormalities in acid-base status are evident.     

Application of a Ridden Horse Pain Ethogram to horses competing at 5-star three-day-events: Comparison with performance

A Ridden Horse Pain Ethogram (RHpE) was previously developed to facilitate the detection of musculoskeletal pain. The objectives were to apply the RHpE during warm-up for the dressage phase of two 5* three-day events and to correlate the RHpE scores with subsequent performance. It was hypothesised that there would be a higher rate of failure to complete the cross-country phase in horses which exhibited ≥7 behaviours compared with those showing <7 behaviours. The RHpE, comprising 24 behaviours, was applied for 10–12 min during warm-up. Gait abnormalities in trot and canter were recorded. Dressage penalties, cross-country performance, showjumping penalties and final placings were documented. Horses were categorised as those which completed cross-country, or those which did not complete because of elimination or retirement. RHpE scores (n = 137) ranged from 0 to 9/24 (median 3 [range 0–9] for nonlame horses; median 5 [range 1–9] for horses with gait abnormalities in trot or canter). There was a moderate correlation between dressage penalty scores and the RHpE score (rho = 0.4, P<0.001, Spearman rank). Fifty-nine per cent of horses (n = 10/17) with a RHpE score ≥7 failed to complete cross-country, compared with 33% (n = 39/117) with a score <7. Horses that failed to complete the cross-country phase had higher RHpE scores compared with those that completed (P = 0.04, W = 8.3, Kruskal–Wallis; pairwise comparison Bonferroni, P = 0.06). There was a significant (rho = 0.3) relationship between total RHpE score and final horse placings (n = 80, P<0.01, Spearman rank). Horses with lameness or gait abnormalities in canter had significantly higher RHpE scores (P<0.01, χ² = 35, chi-square test) compared with other horses. There was a strong correlation between the RHpE scores for horses which competed at both events (P<0.001, rho = 0.6, Spearman rank). The RHpE should facilitate earlier identification of horses which may benefit from diagnosis and treatment, resulting in improvement in both performance and equine welfare.     

水合氯醛对马血气,酸碱值影响的研究

通过对１１匹实验马的血气、酸碱值分析，结果表明以１２ｇ／１００ｋｇ体重的水合氯醛麻醉后，实验马的Ｐｏ２、Ｓａｔ·Ｏ２、Ｃ－Ｏ２三项指标均显著降低，ＰＡ－ａＤＯ２显著增加；而ｐＨ、Ｐｃｏ２、Ｔ－ＣＯ２、ＡＢ、ＳＢ、ＢＥｂ六项指标无显著变化。说明该剂量的水合氯醛对马的呼吸功能有一定影响，且主要影响与氧有关的指标。     

Effect of passive pneumoperitoneum on oesophageal pressure, cardiovascular parameters and blood gas analysis in horses

Reasons for performing study: Standing surgical procedures are being employed to an ever‐greater extent in horses. Pneumoperitoneum during abdominal surgery might adversely affect the work of breathing. Objectives: To determine whether development of pneumoperitoneum during abdominal surgery adversely influences the work of breathing. Methods: Eight healthy mature horses were equipped with carotid artery and thoracic vena cava catheters and an intraluminal manometry system. The following measurements were obtained before and at +5, +10, +15 and +30 min following establishment of pneumoperitoneum by paralumbar puncture using an 8 gauge needle: vital signs, oesophageal pressure, gastric pressure, arterial and central venous blood pressures, and arterial and mixed venous blood gas analyses. Results: Significant changes in oesophageal pressure, central venous pressure and results of arterial and mixed venous blood gas analysis were not detected. Arterial diastolic and mean pressures and rectal temperature increased slightly (P≤0.05). Conclusions: Passive pneumoperitoneum did not adversely affect breathing mechanics or haemodynamic variables under experimental conditions. Changes in arterial pressure could have occurred as a response to the passive pneumoperitoneum or be related to handling stress. Subtle variations in rectal temperature were not clinically relevant and likely resulted from stress associated with restraint. Potential relevance: It is unlikely that mature horses will develop signs of respiratory difficulty as a result of the development of passive pneumoperitoneum during standing laparoscopy.     

Physiologic and biochemical measurements and response to noxious stimulation at various concentrations of MS‐222 in Koi (Cyprinus carpio)

ObjectiveTo evaluate the physiological effect and response to noxious stimulation at five concentrations of MS-222 in koi (Cyprinus carpio).Study designProspective experimental study.AnimalsTwenty-one healthy adult unknown sex koi fish weighing mean 450 ± SD 120 g.MethodsEach fish was exposed to five different concentrations of MS-222 (50, 70, 110, 150 and 190 mg L^?1) in a random sequence during the same anaesthetic event. For each concentration of MS-222, vital functions such as heart rate (HR) (via Doppler) and opercular rate (OpR) were recorded after a standardized induction period. Response to two noxious stimuli in the form of haemostat clamp pressure applied on the tail and the lip was evaluated, and blood was drawn to measure biochemical and blood gas values.ResultsDecrease in response to noxious stimulation with an increase of MS-222 concentration both for the lip (p = 0.0027) and the tail (p < 0.0001) stimulus was observed. Biochemical values were unaffected by the concentration of MS-222 with the exception of lactate concentration which was weakly correlated with the duration of anaesthesia (r = 0.31, p < 0.001) and the number of times the fish was clamped or bled prior to sampling (r = 0.23, p < 0.001). Opercular rate decreased with the increase in anaesthetic concentration, and HR was not affected.Conclusions and clinical relevanceOur results indicated a decrease in response to stimulus and a decrease in OpR that were associated with increased concentrations of MS-222. This may assist in establishing anaesthetic protocols using MS-222 in fish and supports the use of supramaximal pressure stimuli to teleost fish under variable MS-222 concentrations as a model for future studies.