Closed reduction of scapulohumeral joint luxation in an Icelandic horse after general anaesthesia

This report describes the clinical, ultrasonographic and radiographic findings in an 8‐year‐old Icelandic mare with unilateral shoulder luxation after general anaesthesia. Reduction of the luxated humerus was performed in a closed fashion using a calving jack under general anaesthesia. The horse recovered well and ultimately returned to its previous level of performance.     

Stress factors influencing plasma cortisol levels and adrenal weights in Chinese water deer (Hydropotes inermis)

Stress responses were compared in Chinese water deer (Hydropotes inermis) exposed to different handling, management and disease factors by measuring plasma cortisol and adrenal gland weight. Healthy free-ranging deer shot as part of a management programme served as baseline controls; they had lower cortisol levels than either diseased deer or free-ranging deer that were either netted and manually restrained or anaesthetised by dart. Although darting appeared subjectively to be much less stressful to the deer than manual restraint, there was no significant difference in cortisol levels between the two groups. Hand-reared deer that were manually restrained in a similar manner to the free-ranging deer did not react behaviourally any less violently but showed significantly lower plasma cortisol levels. Adrenal glands of deer with various, mostly chronic, disease conditions weighed significantly more than those of healthy deer.     

Effects of two different dosages of dobutamine on pulmonary artery wedge pressure, systemic arterial blood pressure and heart rate in anaesthetized horses

The purpose of the present study was to investigate the effects of two different dobutamine concentrations on pulmonary artery wedge pressure (PAWP) and on mean systemic arterial blood pressure (MAP) in horses anaesthetized with isoflurane, after induction of general anaesthesia with xylazine, ketamine and diazepam. Eight healthy warm-blood horses were included in the study. Each horse was subjected to general anaesthesia twice with two different dosages of dobutamine, 3 and 5 microg/kg bw/min, being infused over 15 min, starting 50 min after induction of general anaesthesia (T(0)). The heart rate, the PAWP and the MAP were recorded after 10 min (T(1)) and then every 5 min until 15 min after cessation of intravenous dobutamine administration (T(3)-T(5)). The PAWP was measured by a right heart catheter, which was positioned in the pulmonary capillaries. Mean systemic arterial blood pressure was monitored at the facial artery for the duration of general anaesthesia. All parameters increased at both dosage rates of dobutamine and decreased significantly when dobutamine administration ceased. The increase in heart rate was significantly higher after administration of 3 microg/kg bw/min dobutamine compared with the dosage of 5 microg/kg bw/min dobutamine. The increase in MAP was also higher at this dosage, but not significantly different to the dosage of 5 microg/kg bw/min dobutamine. During both dosages the MAP was above a value considered to be compatible with good peripheral circulation. The greater increase in PAWP was observed during administration of 5 g/kg bw/min dobutamine, but PAWP was not significantly different with the dosage of 3 microg/kg bw/min dobutamine. In conclusion, the administration of dobutamine led to an increase in MAP and PAWP above a value considered to be compatible with a good peripheral circulation. The results of the present study indicate that dobutamine improves circulation, in addition to its well-known effect on the periphery.     

Pulmonary artery wedge pressure during treadmill exercise in warmblood horses with atrial fibrillation

The heart rate and the pulmonary artery wedge pressure (PWP) was measured in 10 healthy warmblood horses and in six warmblood horses with atrial fibrillation (AF) at rest and during standardised treadmill exercise. During treadmill exercise, the increase in heart rate was significantly higher in the horses with AF than in the healthy horses. Horses with AF showed a significantly higher increase in PWP at treadmill velocities of 5m/s and faster, than did the healthy horses. The differences in PWP between both groups increased with treadmill strain. The present study demonstrates that there is an influence on the haemodynamics in horses with AF during treadmill exercise, which could explain exercise intolerance in some horses with lone AF.     

Pulmonary dysfunction and skeletal muscle changes in horses with RAO

BACKGROUND: Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined. HYPOTHESIS: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses. ANIMALS: Fifteen healthy horses (control) and 50 horses with RAO were examined. METHODS: In a prospective clinical trial, a complete lung examination was performed in all horses. In all horses, muscle enzyme activity at rest and after exercise and muscle biopsies from the M. gluteus medius were examined. RESULTS: None of the horses had clinical or histologic signs of primary or neurogenic myopathies. According to the clinical, endoscopic, and radiographic findings and with a scoring system, the horses with RAO were grouped according to the severity of pulmonary findings (15 horses mild, 24 horses moderate, 11 horses severe RAO). Pathologic changes of the skeletal muscle (fiber atrophy or fiber hypertrophy, myofibrillar degeneration, hyperplasia of mitochondria, and ragged-red-like fibers) were identified in most horses with RAO but in only a few individual control horses. In addition, a marked depletion of muscle glycogen storage was evident in the RAO horses but not in the control group. Other pathologic changes of skeletal muscle such as centralized nuclei and regenerating fibers were rare, but were more frequent in horses with lung diseases than in the control group. The degree of muscle cell changes was also graded with a scoring system and correlated with the severity of pulmonary disease (r= 0.55). CONCLUSION: Chronic pulmonary disease in horses is associated with structural changes in skeletal muscle. CLINICAL IMPORTANCE: Because chronic pulmonary disease may affect muscles, early and effective therapy may prevent these changes. This finding could be of clinical importance but requires further studies.     

Type C virus from cell cultures of chemically induced rat hepatomas

Type C RNA viruses are present in cell cultures from transplantable and primary hepatomas induced by aromatic amine carcinogens. Virus yield was markedly enhanced by treating the cells with bromodeoxyuridine. Preparations of rat hepatoma-associated virus obtained from cultures treated with this compound were deficient in DNA polymerase activity.