bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer processing of transaortic valve blood pressures in the horse using the first derivative of the left ventricular pressure trace
Authors: MILLER P. J. , HOLMES J. R. 
Published: April 2010

SummaryA method is described of processing transaortic valve pressures in the horse using the first derivative of the left ventricular pressure to define the beginning and end of each systolic complex. To determine the beginning of each systole three definitions of left ventricular end diastolic pressure (LVEDP), based on a 100, 150 or 200 mmHg/sec rate of left ventricular diastolic pressure rise, were evaluated. These definitions were also evaluated for their ability to determine isovolumic contraction time (ICT) and pulse interval. The best of these, LVEDP 150, was defined as the last point in diastole before a rate of rise of left ventricular pressure (LVdP/dt) equal to or exceeding 150 mmHg/sec sustained over 44 msecs. The end of left ventricular ejection was estimated from the left ventricular pressure trace as the point at which — LVdP/dtmax occurred. There was good agreement between the values of left ventricular ejection time (LVET) measured to the incisura of the aortic pressure trace and LVET calculated to the time of —LVdP/dtmax (r = 0.991). The importance of visually examining the waveforms before committing them to automatic processing is emphasised.
Mammary secretions in normal spontaneous and induced premature parturition in the mare
Authors: LEADON D. P. , JEFFCOTT L. B. , ROSSDALE P. D. 
Published: April 2010

SummaryTotal calcium, total protein, albumin and globulin content were determined in 49 samples of mammary secretions from 37 crossbred and Thoroughbred mares. The mares were divided into three categories: Group 1 — post partum samples from spontaneous full term Thoroughbred deliveries (n = 20); Group 2 — pre‐ and post partum samples from spontaneous full term Thoroughbred deliveries (n = 6); Group 3 — pre‐ and post partum samples from induced premature deliveries in crossbred mares (n = 11). Calcium concentrations of the mammary secretions proved useful in predicting full term and also in assessment of the chances of foal survival in prematurely induced parturition. Mean (±se) calcium levels in full term mares that foaled spontaneously (Group 1) were 10.6±2.7 mmol/litre on the day of parturition. However lower values than this did not necessarily mean parturition would not take place. In Group 2 mares, calcium levels were 4.1±0.8 mmol/litre just before foaling and rose to 9.2±1.5 mmol/litre within 20 mins of parturition; an increase of 124 per cent. Group 3 mares, induced prematurely, showed poor foal survival if pre‐partum calcium levels were less than 3 mmol/litre. Total protein, albumin and globulin concentrations showed a similar trend but the increase just before or during parturition was much less marked.
Concentrations of 15‐keto‐13, 14‐dihydro‐prostaglandin F2α in the mare during spontaneous and oxytocin induced foaling
Authors: STEWART D. R. , KINDAHL H. , STABENFELDT G. H. , HUGHES J. P. 
Published: April 2010

SummaryChanges in plasma 15‐keto‐13, 14‐dihydro‐prostaglandin F2α were monitored at frequent intervals before, during and after spontaneous deliveries (three mares) and foalings induced by oxytocin (eight mares). No evidence of increased concentrations of the prostaglandin metabolite was observed in the final 10 days of gestation. In spontaneously delivering mares, there was a marked increase from 3 ng/ml at −125 mins to 18 ng/ml at −65 mins to the highest observed value of 182 ng/ml at 20 mins pre‐partum. Following delivery, concentrations declined rapidly to around 0.2 ng/ml. Further release of prostaglandins was seen on Days 1 and 3 post partum. In oxytocin induced mares, maximal concentrations of about 100 ng/ml were observed to occur very close to the time of delivery. Large increases were observed as early as 2 mins following oxytocin injection. The significance of these findings is discussed in relation to parturient and post parturient events and changes in levels of the hormone relaxin during the same period.
Studies on equine prematurity 5: Histology of the adrenal cortex of the premature newborn foal
Authors: WEBB P. D. , LEADON D. P. , ROSSDALE P. D. , JEFFCOTT L. B. 
Published: April 2010

SummaryThe histology of the adrenal cortex of prematurely induced newborn pony foals in relation to their ability to survive the neonatal period is described.
Hypothyroidism in the foal
Authors: IRVINE C. H. G. 
Published: April 2010

SummaryHypothyroidism in the foal occurs as two entities because of the separate actions of thyroid hormones in regulation of metabolic rate and in cell differentiation. The hypometabolic state which results in inadequate thermogenesis and lethargy, occurs concurrently with a period when thyroid hormone secretion is inadequate. Also the severity of the concurrent symptoms is related to the degree of hormone inadequacy as measured by plasma concentrations of free T4 and T3. By contrast, the developmental lesions caused by hypothyroidism are often observed during periods when plasma thyroid hormone concentrations are normal. This is because during the development of most tissues there is a period during which deprivation of thyroid hormones leads to developmental defects which may first appear weeks or months later, by which time thyroid hormone levels may have returned to normal. In the foal the critical period for some developmental processes, eg, myelination, is before birth so it is difficult to confirm a pre‐natal hypothyroid state as the cause of neonatal neuromuscular incompetence. Post natal developmental lesions of the epiphyses or ossification centres, for example, may also manifest themselves some weeks subsequent to the period during which hypothyroidism existed. Because confirmation of diagnosis using plasma hormone measurements is very difficult in the foal, and because the symptoms of hypothyroidism are not specific, the incidence of confirmed hypothyroidism in foals is low. However there is suggestive evidence that where awareness of the condition exists it is diagnosed frequently. The aetiology is obscure although diet has been implicated. While treatment with thyroxine by any route is an effective and economical method of raising plasma hormone concentrations, it is obviously useful only if given while thyroid hormone levels are low
Neurological examination of newborn foals
Authors: ADAMS RAGAN , MAYHEW I. G. 
Published: April 2010

SummaryBehaviour and response to neurological testing of apparently healthy newborn foals differed significantly from the adult in several ways. Foals responded to external stimulation with exaggerated movements although they tended to sink into a relaxed state when restrained. They had a more angular head position and assumed a base wide stance. The menace reflex developed during the first two weeks post partum. In general, the foals' gait was choppy or dysmetric. In lateral recumbency the foals had increased extensor tone, hyperreflexive tendon reflexes, crossed extensor reflexes as well as recumbent extensor thrust reflexes in all four limbs.
Developments in management of the newborn foal in respiratory distress 1: Evaluation
Authors: KOSCH P. C. , KOTERBA ANNE M. , COONS T. J. , WEBB A. I. 
Published: April 2010

SummaryDevelopments in evaluation of newborn foals with respiratory distress are discussed. Major causes of respiratory distress are outlined and discussed in terms of the similar respiratory signs exhibited by foals with this clinical syndrome. History, physical examination, clinical pathology, chest radiography and blood gas analyses are discussed as important elements of the evaluation of the condition of these foals. Foals with respiratory disease are grouped into three major categories on the basis of clinical signs and arterial blood gas profiles. The evaluation of foals with respiratory distress is designed not only to reach an accurate diagnosis of the aetiology but also to define the foal's need for respiratory support.
Response to oxygen administration in foals: Effect of age, duration and method of administration on arterial blood gas values
Authors: STEWART JENNIFER H. , ROSE R. J. , BARKO ANNE M. 
Published: April 2010

SummaryThe effect of oxygen administration on blood gas values was examined in six newborn foals from birth to seven days old. Three variables were studied: the effect of increasing age on the ability to elevate arterial oxygen tension (Pao2), the effect of duration of oxygen delivery onPao2and the effect of method of administration. The results demonstrated a significant effect of age on the ability to increasePao2values, with the highestPao2values being found at seven days old. The duration of oxygen administration caused little change inPao2values; peak values were reached after 2 mins of oxygen inhalation and changed little throughout the 20 min administration. No significant differences were found inPao2when oxygen was administered via a face mask, compared to administration at 10 litres/min via an intranasal tube. The clinical importance of these findings is discussed, along with the factors which may be involved in the inability to elevatePao2in the early post natal period.
Blood pressure, electrocardiogram and echocardiogram measurements in the growing pony foal
Authors: LOMBARD C. W. , EVANS M. , MARTIN LAURA , TEHRANI JOY 
Published: April 2010

SummaryTwelve newborn pony foals underwent cardiovascular examinations (auscultation, arterial blood pressure measurements, electrocardiograms and M‐mode echocardiograms) on their first day of life and then on Days 7, 14, 21, 30, 60 and 90. An age dependent, statistically significant, rapid increase of the arterial blood pressure in the first month was documented together with a slower decrease of the resting heart rate after two and three months of life. Innocent soft systolic murmurs were audible over the left heart base in a large number of the foals. The electrocardiograms showed age dependent increases of the PR‐, QRS‐ and QT‐ intervals and a trend of the mean electrical axis in the frontal plane to rotate towards the left side. The ventricular dimensions, measured by M‐mode echocardiography, increased with the growth of the pony foals. Linear regression equations were calculated for the right and left ventricular internal dimensions in relation to body weight (bwt). The other echocardiographic parameter had low correlations with bwt.
Haematology of foals up to one year old
Authors: HARVEY J. W. , ASQUITH R. L. , McNULTY PATRICIA K. , KIVIPELTO JAN , BAUER J. E. 
Published: April 2010

SummaryPacked ceil volume, haemoglobin concentration, erythrocyte counts, erythrocyte indices, serum iron, iron binding capacities, total and differential leucocyte counts, platelet counts, total plasma protein, fibrinogen, haptoglobin and icterus index values were determined at 14 different ages in eight Thoroughbred and 14 Quarterhorse foals during the first year of life. Absolute neutrophil numbers in blood decreased and lymphocyte numbers increased during the first months. Absolute eosinophil numbers tended to increase until three months old. Haemoglobin concentration and packed cell volume decreased significantly during the first two weeks and generally stayed in the lower portion of adult horse normal ranges during the remainder of the first year. Mean cell volume decreased to minimum values at approximately four months and then gradually increased. Serum iron was high at birth and decreased rapidly to a minimum at three days old. Total iron‐binding capacity increased to a maximum at one month. Serum haptoglobin was generally within the adult normal range at birth. A moderate, but significant, decrease occurred at one week old. Fibrinogen concentration increased to a maximum at five months. Icterus index values decreased rapidly during the first two weeks of life. Minor changes occurred in other parameters measured. Possible causes for the various changes in haematological parameters are discussed.
Preliminary study on the pharmacokinetics of phenobarbital in the neonatal foal
Authors: SPEHAR ANDREA M. , HILL M. R. , MAYHEW I. G. , HENDELES L. 
Published: April 2010

SummaryPharmacokinetic characteristics of the anticonvulsant phenobarbital were studied in seven pony and two Thoroughbred foals aged between four and 10 days. A single, 20 mg/kg body‐weight (bwt) dose of phenobarbital was given intravenously over 25 mins and the serum concentrations of the drug were measured using an EMIT AED assay (coefficient of variation 1.37 per cent at 30 μg/ml, n = 7). Phenobarbital elimination was found to follow first order kinetics. The mean (±sd) peak phenobarbital serum concentration was 18.6 ± 2.1 μg/ml at 1h after initiation of infusion with a mean (± se) half‐life of 12.8 ± 2.1h. The mean (± se) volume of distribution was 0.86 ± 0.026 litres/kg bwt and mean (±se) total body clearance was 0.0564 ± 0.0065 litres/kg bwt/h. Sedation was noticed 15 to 20 mins after the beginning of infusion and lasted for up to 8h. All foals could be aroused and could walk although they were ataxic for the first 1 to 2h. A degree of delayed hyper‐excitability occurred 3 to 8h after infusion. In equine neonatal seizure disorders it is recommended to use a loading dose of 20 mg/kg bwt of phenobarbital, followed by maintenance doses of 9 mg/kg bwt at 8h. With this regimen, average steady state serum phenobarbital concentrations should range between approximately 11.6 and 53 μg/ml. Phenobarbital serum concentrations should be monitored following the loading dose and 24h after initiating the maintenance doses to check that levels remain within the suggested (human) therapeutic range of 15 to 40 μg/ml.
Intracranial haemorrhage in pre‐viable, premature and full term foals
Authors: PALMER A. C. , LEADON D. P. , ROSSDALE P. D. , JEFFCOTT L. B. 
Published: April 2010

SummaryA neuropathological examination was carried out on the brains of 58 foals. Forty‐two were pony foals induced at various periods of gestation from 200 days onwards. Two were pre‐viable pony foals delivered by caesarean section and 14 were Thoroughbred foals (one set of twins, two stillborn, five premature, two dysmature, two convulsive and one induced). The only significant pathological change involved intracranial haemorrhage. Subarachnoid haemorrhage occurred in all of 10 pony foals induced before 301 days of gestation and in two pony foals born by caesarean section at 270 and 280 days gestation. Subarachnoid haemorrhage was also present in some pony and Thoroughbred foals born after 301 days gestation; the incidence usually appeared greater in those pony foals which survived for the shortest periods. Haemorrhage also occurred elsewhere in the brains, including the cerebral white matter, the molecular layer of the cerebellum and the medulla, but the intensity could not be related to either length of gestation or duration of survival. No other neuropathological changes were found that could account for the functional state of the animals, whether they were pre‐viable, premature, dysmature or convulsive.
Results of treatment of subchondral bone cysts in the medial condyle of the equine femur with an autogenous cancellous bone graft
Authors: KOLD S. E. , HICKMAN J. 
Published: April 2010

SummaryThe results of surgical treatment of 10 subchondral bone cysts, all located in the medial femoral condyle, are presented. A cancellous bone graft was used in nine cases and a two component acrylic bone cement was used in the case of an extremely large cyst. Eight out of the 10 cases made a satisfactory clinical recovery.
Clinicopathological studies on neurectomy in equids
Authors: SAID A. H. , KHAMIS Y. , MAHFOUZ M. F. , HEGAZY A. 
Published: April 2010

SummaryClinical and pathological changes following neurectomy were studied experimentally in 46 male and female equids. Sixty‐three operations were performed using either the traditional or the Fackelman and Clodius methods of neurectomy. The effect of arteriovenous ligation was studied in 12 animals and 20 angiograms were performed post mortem to study the arterial pattern of the extremities of the operated limb. Neuroma formation (31 cases) and sloughing of the hoof (five cases) were the two main untoward sequelae. Neurectomy by the technique of Fackelman and Clodius proved superior to the traditional method. No essential changes were observed after ligation of the blood vessels, except in one case where collateral circulation was established.
Relationship between intervertebral joint morphology and mobility in the equine thoracolumbar spine
Authors: TOWNSEND H. G. G. , LEACH D. H. 
Published: April 2010

SummaryThe anatomical features of 21 equine thoracolumbar spines, obtained from horses with clinically normal backs, were examined and the results compared with recent data on the mobility of the joint complexes of the horse's spine. The thoracolumbar spine can be divided into four regions based upon the morphology of the joint complexes: the first thoracic intervertebral joint (T1‐2), the cranial and mid thoracic region (T2‐T16), the caudal thoracic and lumbar region (T16‐L6) and the lumbosacral joint. The mobility of the intervertebral joints in each of these regions can be related to their morphology, particularly the shape, size and orientation of the articular facets and the presence and frequent fusion of the lateral joints of the lumbar spine. The shape and thickness of the intervertebral discs also appear to be of importance.
Collection and evaluation of tracheobronchial washes in the horse
Authors: WHITWELL KATHERINE E. , GREET T. R. C. 
Published: April 2010

SummaryA flexible endoscope was used to obtain 223 tracheal washes from 191 horses in three clinical categories. Total cell counts, cytological and bacteriological examinations are reported and the features of the main cell types encountered described. The presence and degree of inflammatory airway disease was determined by a semiquantitative assessment of the neutrophil response and was an important consideration in the interpretation of the bacteriological results. Potential pathogens were isolated from approximately 30 per cent of samples. Cytological changes suggestive of lungworm infestation, virus infection and chronic airway disease are described. Haemosiderophages, indicative of pulmonary haemorrhage, were found in all horses in full training.The techniques used were rapid and simple and were found to improve the accuracy of diagnosis of pulmonary disease. Sequential samples were useful for monitoring the progress of clinical cases.
Outbreak of botulism in horses
Authors: KELLY A. P. , JONES R. T. , GILLICK J. C. , SIMS L. D. 
Published: April 2010

SummaryAn outbreak of nervous disease in Standardbred horses occurred near Bendigo, in south‐eastern Australia, in October 1980. Over a two week period 11 horses in four training stables were affected with gait abnormalities, depression and recumbency. Eight of the 11 died. The results of an investigation implicatedClostridium botulinumtoxin as the cause. The toxin was food‐borne as a contaminant of oaten chaff.
Importance of uniform cuff application for equine blood pressure measurement
Authors: PARRY B. W. , ANDERSON G. A. 
Published: April 2010

SummarySeventeen horses were used to determine the variances associated with blood pressure cuff application (sp2) and with other inherent errors (sO2). Systolic pressure values had sp2= 3.9 mmHg and sO2= 5.6 mmHg, while diastolic pressure values had sp2= 1.1 mmHg and sO2= 4.4 mmHg. Thus, to be considered different, two blood pressure means (in mmHg), each derived from three readings, had to differ by at least 3.9 for systolic pressure and 3.4 for diastolic pressure when all readings were made without cuff displacement; 6.8 for systolic pressure and 4.6 for diastolic pressure when the cuff was reapplied between, but not during, measurement of each mean; and 5.0 for systolic pressure and 3.8 for diastolic pressure when the cuff was reapplied between all readings. It was concluded that uniform cuff application is readily achieved.
Cardiopulmonary effects of dopamine hydrochloride in anaesthetised horses
Authors: TRIM CYNTHIA M. , MOORE J. N. , WHITE N. A. 
Published: April 2010

SummaryDopamine hydrochloride was infused intravenously into six horses anaesthetised with halothane. Three dose rates; 0.5, 2.5 and 5.0 μg/kg/min, were evaluated in each horse. The cardiac output was significantly increased at 15 and 30 mins following administration of dopamine at 2.5 and 5.0 μg/kg/min. The heart rate, facial artery pressure and pulmonary artery pressure remained unchanged. Total peripheral resistance was significantly decreased at 30 mins with 2.5 μg/kg/min and at 15 and 30 mins with 5.0 μg/kg/min. No significant change was produced in packed cell volume, total protein, white blood cell count, platelets, glucose or lactate at any infusion rate. Supraventricular premature contractions occurred in one horse and episodes of tachycardia occurred in two horses during infusion of dopamine at 5.0 μg/kg/min. The results of the investigation demonstrated that dopamine administered at 2.5 and 5.0 μg/kg/min effectively increased the cardiac output of halothane anaesthetised horses and that dopamine at the high dosage may cause dysrhythmias.
Sacroiliac lesions as a cause of chronic poor performance in competitive horses
Authors: JEFFCOTT L. B. , DALIN G. , EKMAN STINA , OLSSON S.‐E. 
Published: April 2010

SummaryThe histories and clinical signs in 11 horses with longstanding poor performance attributed to chronic sacroiliac damage are described. The main clinical feature was a lack of impulsion from one or both hindlimbs causing a restriction in the hind gait or lowgrade lameness. A temporary improvement was often achieved using anti‐inflammatory medication, but eventually all the horses were killed because of unsatisfactory progress at exercise. Post mortem examination revealed that changes were confined to the sacroiliac joints. The macroscopic and histological findings varied considerably and in only two cases could the changes be classified histologically as arthrosis. In the other nine horses there was increased joint surface area or irregular outline associated with extensions of the joint on the caudomedial aspect. These changes were interpreted as indicating a chronic instability of the joint leading to restriction of hindlimb impulsion. The underlying cause of the problem was not ascertained but the significance and possible pathogenesis of the lesions are discussed.
Measurement of IgG in equine blood by immunoturbidimetry and latex agglutination
Authors: KENT JOYCE E. , BLACKMORE D. J. 
Published: April 2010

SummaryThis paper describes the quantitative measurement of IgG concentrations in equine blood/serum by turbidimetric analysis and the qualitative assessment using latex agglutination. The concentration of IgG in foal serum measured by turbidimetry correlated well with the results obtained by radial immunodiffusion (r = 0.91) and the γ‐globulins estimated from the electrophoresis of serum on cellulose acetate (r = 0.92). The method, using antibody‐coated latex beads, to detect foals with serum IgG concentrations of less than 4 g/litre (whole blood less than 2 g/litre) proved to be accurate in 96 per cent of cases and provided a quick and simple qualitative test, suitable for use outside the laboratory.