A steroid anaesthetic for cats

Extract

Hans Selye, at McGill University, Montreal, was the first to demonstrate the anaesthetic activity of steroids — in 1941. While investigating the effects of overdosage of several steroid hormones in rats, he discovered that large amounts injected intraperitoneally induced anaesthesia. His observations have led to the development, some 30 years later, of a new steroid anaesthetic. The preparation was investigated under the provisional name CT 1341, and clinical trials in animals and man have shown that it possesses many useful properties. This preparation is now available under the trade name “Saffan” (Glaxo).     

Epidemiology in Relation to Methods for Forecasting Light Leaf Spot (Pyrenopeziza brassicae) Severity on Winter Oilseed Rape (Brassica napus) in the UK

Pyrenopeziza brassicae, cause of light leaf spot of oilseed rape, has a complex polycyclic life cycle. It can be difficult to control light leaf spot in winter oilseed rape in the UK since it is not easy to optimise fungicide application timing. Early autumn infections are usually symptomless and recognisable lesions do not develop until the epidemic has progressed further by the spring. Light leaf spot often has a patchy distribution in winter oilseed rape crops and estimation of disease incidence can be difficult. There is evidence that epidemics are initiated primarily by ascospores produced from apothecia that survive the summer inter-crop period on infected debris. Subsequent development of the epidemic during the winter and spring is maintained by rain-splashed conidia that spread light leaf spot from initial foci. Understanding the relative roles of ascospores and conidia in the light leaf spot life cycle is crucial for forecasting epidemic severity and developing control strategies. The current web-based regional forecast system provides an autumn forecast of the incidence of light leaf spot that can be expected the following spring. This is based on survey data which assesses the occurrence of disease the previous July, and weather factors, such as deviations from summer mean temperature and winter rainfall. The forecast can be updated throughout the autumn and winter and includes crop-specific elements so that growers can adjust risks by inputting information about cultivar, sowing date and fungicide use. Crop-specific forecasts can be confirmed by assessing the incidence of light leaf spot. Such assessments will become easier when immunodiagnostic methods for detection of the disease become available. Incorporation of information on spore biology (e.g. apothecial maturation, ascospore release and infection conditions) is considered as a component of the interactive, continuously updated, crop-specific, web-based forecasts which are needed in the future.     

Mosquito bite-caused eosinophilic dermatitis in cats.

Eight cats had lesions on the nasal bridge, ears, and footpads, with histologic and hematologic features of a recently described seasonal form of eosinophilic granuloma complex. Four cats were examined in detail, and it was established that 2 of the 4 reacted to mosquito extract on intradermal skin testing read at 20 minutes. Neither of the 2 cats tested had deposits of immunoglobulins in lesional or perilesional skin. Lesions on all 4 cats resolved when kept at home behind insect screening, but flared up if the screening was removed. Mosquitoes that were observed to be biting and causing lesions were collected and identified. Other species of laboratory-reared mosquitoes were allowed to bite nonlesional skin of 1 affected cat, causing pruritus, erythematous crusting, and ulcerative lesions at the bite site, which was characterized histologically as eosinophilic dermatitis.     

Determination and repeatability of maximum oxygen uptake and other cardiorespiratory measurements in the exercising horse

A rapid incremental treadmill exercise test was used to determine the repeatability of the following measurements in exercising horses: maximal oxygen consumption (VO2max), maximal heart rate (HRmax), velocity at a heart rate of 200 beats/min (V-200), oxygen consumption at a heart rate of 200 beats/min (VO2-200), oxygen consumption at HRmax (VO2-HRmax), work rate at a heart rate of 200 beats/min (W-200), work rate at HRmax (W-HRmax) and treadmill velocity at HRmax (V-HRmax). Six Standardbred geldings were exercised on three separate occasions on a treadmill set at an inclination of 6 degrees. The exercise protocol was that each horse was exercised for 2 mins at 3 m/sec, after which the treadmill speed was increased by 1 m/sec every 60 secs, until the horse could no longer maintain its speed. A minimum of 24 h was allowed between repeated tests. No significant differences were found between the three means of any of the eight cardiorespiratory variables with repeated measurement. Variables with high coefficients of variation (greater than 10 per cent) included V-HRmax, W-HRmax and VO2-HRmax. The V-200, W-200 and VO2-200 showed less variation. The VO2max showed good reproducibility, there being coefficients of variation ranging from 1.4 to 9.0 per cent. The individual horse values for VO2max ranged from 104 to 169 ml/kg bodyweight/min. Maximal heart rate was also highly reproducible and the coefficients of variation were less than or equal to 2.7 per cent in all horses. It is concluded that the measurement of VO2max has good reproducibility, but other estimates of maximal aerobic capacity are less precise.     

Precautions when using opioid agonist analgesics.

Opioid agonist analgesics are effective drugs for treating postoperative pain. Contraindications for their use are primarily respiratory depression and increased intracranial pressure. Their use may mask potentially serious postoperative complications.