bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspects of the pathology of stifle bone cysts in the horse
Authors: JEFFCOTT L. B. , KOLD S. E. , MELSEN F.
Published: April 2010

The gross and histological appearance of subchondral bone cysts in six Thoroughbred or partbred horses is described. The lesions were all situated in the centre of the medial femoral condyle and were not associated with any other damage to the articular surface of the femorotibial or femoropatellar joints. In three cases the cysts were unilateral but had an early noncystic lesion present in the opposite stifle. All the cysts had a narrow channel at their distal extremity which communicated with the femorotibial joint. The more recently developed ones were fluid filled and contained fibrous strands, while those in the older horses contained dense fibrotic detritus. No signs of significant ossification of the cysts were detected. The likely pathogenesis of these lesions is discussed in the light of the pathological findings.

On décrit les aspects microscopique et histologi que de kystes osseux sous cartilagineux tels qu'on les rencontre chez les Pur Sang et Demi Sang. Toutes les lésions étaient situées dans le centre du condyle fémoral médial (interne); elles n'etaient pas asso ciées à d'autres lésions de la surface articulaire des articulations fémoro tibia ou fémoro rotulienne. Aucun signe évident d'ossification de ces kystes ne fut constaté. La pathogènie la plus vraisemblable de ces lésions est étudiée en fonction des constitutions pathologiques. Dans trois cas, les kystes étaient unilatéraux mais déjà une lésion précoce, non kystique existait sur l'articulation symétrique. Tous les kystes présentaient à leur extrémité distale un étroit canal établissant une communication avec l'articulation fémoro tibiale. Les plus récents étaient remplis de liquide et contenaient du matériel fibreux. Ceux des chevaux les plus âgés renfermaient des débris fibreux.

Das makroskopische und das histologische Aussehen subchondraler Knochenzysten bei sechs Vollblut — oder Warmblutpferden wird beschrieben. Die Läsionen lagen alle im Zentrum des medialen Condylus des Femurs; es bestanden kein gleichzeitigen Schäden der Gelenksoberfläche in den demorotibialen und femoro‐patellären Gelenken. In drei Fällen waren die Zysten unilateral, aber im gegenüberliegenden Kniegelenk fand sich eine frühe nicht‐zystische Veränderung. Alle Zysten wiesen an ihrem distalen Ende einen engen Kanal zum Femorotibialgelenk auf. Die frischeren Zysten waren mit Flüssigkeit und fibrösen Fasern gefüllt, während diejenigen älterer Pferde dichten fibrösen Detritus enthielten. Es fanden sich keine Zeichen einer wesentlichen Ossifikation der Zysten. Die wahrscheinliche Pathogenese dieser Läsionen wird im Licht der pathologischen Befunde diskutiert.
Leptospiral infection in aborted equine foetuses
Authors: ELLIS W. A. , BRYSON D. G. , O'BRIEN J. J. , NEILL S. D.
Published: April 2010

During an investigation of equine abortion, leptospiral infection was demonstrated in nine out of 22 foetuses examined by immunofluorescence and culture. Strains belonging to four serogroups (Australis, Pomona, Hebdomadis and Icterohaemorrhagiae) were isolated. The age of leptospira infected foetuses ranged from six months to term.

Au cours de recherches sur les avortements équins, on établit l'existence d'une infection leptospirosique sur neuf des 22 foetus examinés par immunofluorescence et par culture. Les souches appartenaient à quatre sérogroupes (Australis, Pomona, Hebdomadis et Icterohaemorrhagiae). L'âge des foetus infectés variait de six mois à 11 mois.

Während einer Untersuchung von Pferdeaborten konnte aus neun von 22 Foeten eine Leptospireninfektion durch Immunfluoreszenz und Kultur nachgewiesen werden. Die Stämme gehörten zu vier Serogruppen (Australis, Pomona, Hebdomadis und Icterohaemorrhagiae). Das Alter der leptospireninfizierten Foeten variierte von 6 Monaten bis zum Austragealter.
SEM study ofStrongylus vulgarislarva‐induced arteritis in the pony
Authors: WHITE N. A. , MOORE J. N. , DOUGLAS M.
Published: April 2010

This paper describes the histological and scanning electron microscopical examinations of the right colic artery of eight ponies. Lesions all had large thrombi surrounding a larva or larvae, with arterial wall thickening. Endothelial shape change, degeneration and loss were present. Fibrin‐platelet red blood cell aggregates were present on endothelial surfaces as well as on the surface of thrombi. Damage to the intima appeared to produce the conditions for progressive thrombus formation.

Cet article rapporte les résultats obtenus dans l'étude de l'artère colique droite de sept poneys à l'aide du microscope scanner électronique et du point de vue histologique. Toutes les lésions comportaient de gros thrombus formés autour d'une ou de plusieurs larves et un épaississement de la paroi artérielle. Des modifications de l'endothélium ‐perte, dégénérescence et altérations morphologiques furent constatées. Des agrégats de fibrine, de plaquettes et de globules rouges furent observés sur les surfaces endothéliales et sur la surface des caillots. Les lésions de l'intima favorisèrent la formation des thrombus.

Dieser Artikel beschreibt die histologischen und elektronen‐mikroskopischen (Raster) Untersuchungen der rechten Colon‐Arterie von acht Ponys. Die Läsionen wiesen alle grosse Thromben um eine oder mehrere Larven herum auf, begleitet von einer Verdickung der Arterienwand. Veränderungen des Epithelsaussehens, Degeneration und Endothels verlust warens nachzuweisen. Aggregate von Fibrin, Thrombozyten und Erythrozyten fanden sich auf den Endotheloberflächen, sowie auf der Oberfläche der Thromben. Der Schaden an der Intima scheint die Voraussetzungen für die progressive Thrombusbildung zu schaffen.
C‐cell tumours of the thyroid in the horse
Authors: LUCKE VANDA M. , LANE J. G.
Published: April 2010

The clinical and pathological aspects of two cases of C‐cell (parafollicular cell) tumours of the thyroid are described. Both the horse and the pony presented with a paralaryngeal mass and a history of constant gulping. Ultrastructural examination of the tumours demonstrated that they were composed of C‐cells containing typical, membrane‐bound secretory granules. The pony is alive and well three years after surgery and the horse has raced successfully following removal of the tumour.
Method of selective and non‐selective angiocardiography for the horse
Authors: CARLSTEN J. , KVART C. , JEFFCOTT L. B.
Published: April 2010

A practical and safe method of angiocardiography for the horse is described. The technique involved the rapid injection of 50 to 150 ml contrast agent via catheters in the right and left heart, pulmonary artery and aorta. The examination was carried out with the horse in the standing position or under general anaesthesia. Angiocardiograms were performed on 10 normal horses and satisfactory pictures of the right and left ventricles, pulmonary arteries, aorta and coronary circulation were obtained. The technique was also used in a foal with severe congenital heart disease. The most practical methods of recording the images in the standing position were cinefilm or video taperecording. In the recumbent position both cinefilm and radiographs were taken. No damage to the heart was inflicted by the catheters and only a few ventricular premature contractions (less than five) were produced by the pressure of injection. No signs of toxicity were recorded using repeated injections of contrast material (ie, less than 600 ml).
Survey of resting blood pressure values in clinically normal horses
Authors: PARRY B. W. , McCARTHY M. A. , ANDERSON G. A.
Published: April 2010

Resting coccygeal blood pressure values were measured, indirectly, on 296 horses (97 Thoroughbreds, 97 Standardbreds and 102 hacks). Blood pressure was found to vary with the class of horse examined; on average Thoroughbreds had significantly higher values than Standardbreds and hacks, whereas blood pressures of the last two groups were not significantly different. There was no demonstrable effect of sex, height or heart rate on blood pressure, but temperature and age did influence the value recorded. Mean (± sd) (n = 296) coccygeal uncorrected values (systolic pressure/diastolic pressure) were 112.1 ± 16.5/77.3 ± 14.3 mmHg. Allowing for bladder width to tail girth ratios used in each measurement, actual coccygeal pressures of 122.8 ± 18.6/71.0 ± 13.4 mmHg were determined. The latter corresponded to values of 149.4 ± 19.0/97.6 ± 14.0 mmHg, when corrected to heart (shoulder) level. Normal limits (defined as within 2.5th and 97.5th percentiles) for all horses, regardless of class, were 80 to 144 mmHg/49 to 105 mmHg for coccygeal uncorrected values and 86 to 159 mmHg/45 to 97 mmHg adjusted for bladder width to tail girth ratio.
Cardiovascular and pulmonary effects of recumbency in two conscious ponies
Authors: HALL L. W.
Published: April 2010

Respiratory dead‐space, tidal volume, respiratory rate, blood gases, cardiac output, heart rate and arterial and pulmonary arterial blood pressures were measured in two conscious, trained ponies in the standing position and in left lateral recumbency. The ponies were reluctant to remain lying down for more than about 20 mins but the reason for this did not become apparent. Tidal volume was reduced during recumbency but the respiratory rate increased, tending to maintain the minute volume at about that of the standing animal. Arterial carbon dioxide tension did not change significantly from standing values but the mean arterial oxygen tension values tended to decrease in both ponies during recumbency because of a slight increase in pulmonary venous admixture. Venous admixture in these two laterally recumbent conscious animals was considerably less than previously reported for anaesthetised subjects.
Comparison of carbon fibre and nylon suture for repair of transected flexor tendons in the horse
Authors: NIXON A. J. , STASHAK T. S. , SMITH F. W. , NORRDIN R. W.
Published: April 2010

Carbon fibre‐polylactic acid composites and monofilament non‐absorbable suture material were compared for the repair of surgically transected superficial digital flexor tendons in 10 horses. All surgical wounds healed by first intention. The repaired tendons were enlarged, the carbon implanted tendons being larger than those sutured. The horses were killed at six, eight, 12, 20 or 24 weeks. Greater fibrous thickening occurred in tendons repaired with carbon fibre, especially at 12 weeks postoperatively. Carbon fibre incited a greater histological response with macrophages, lymphocytes, plasma cells, eosinophils and fibroblasts. The fibrous tissue in the repair sites appeared to mature and the collagen to align at a similar rate irrespective of the method of repair. Only that tissue within and immediately surrounding the carbon bundles was immature at six months. There was minimal tendency for carbon filaments to separate and those that did were often surrounded by epithelioid macrophages forming a granuloma. Massive eosinophil concentrations were present between each granuloma. With each sequential test period the sutured tendons became increasingly stronger than the carbon implanted tendons. This may have been because of the immature core of tissue associated with the carbon bundles. No carbon particles were detected in draining lymph nodes.
Fetlock annular ligament desmotomy: A report of 24 cases
Authors: GERRING E. L. , WEBBON P. M.
Published: April 2010

Restriction of free movement of the flexor tendons through the fetlock canal results in lameness. The commonest cause was chronic synovitis of the digital sheath. The condition is characterised by an unremitting lameness, synovial distension and a notch on the caudal aspect of the limb. The condition can be relieved by section of the annular ligament of the fetlock. In a series of 24 cases 16 horses returned to work with no recurrence of lameness, three cases were lost to follow up and five animals remained lame; three of these had intercurrent disease.
Radioisotope bone scanning in horses
Authors: ATTENBURROW D. P. , BOWRING C. S. , VENNART W.
Published: April 2010

The detection of radionuclide activity in the living equine skeleton, using bone seeking radiopharmaceuticals and a hand‐held radiation detector, is reported. Pathological changes in bone can be detected and subsequent development monitored. The availability and use of this diagnostic technique in equine practice is discussed.
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

A 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

Total 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

Changes 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

The 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

Hypothyroidism 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

Behaviour 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

Developments 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

The 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

Twelve 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

Packed 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

Pharmacokinetic 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

A 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

The 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

Clinical 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

The 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

A 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

An 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

Seventeen 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

Dopamine 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

The 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

This 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.
Maximal anaerobic (lactic) capacity and power of the horse
Authors: SAIBENE F. , CORTILI G. , GAVAZZI P. , SALA A. , FAINA M. , SARDELLA F.
Published: April 2010

Blood lactate concentrations were determined in 16 horses (three Thoroughbreds, seven Standardbreds and six polo ponies) before and 5 mins after they galloped over distances of 200, 300 and 400 m at maximal speed. The highest net lactate concentration (Δ Lamax) of 14 to 15 mmol/litre was attained by the polo ponies and the highest speed by the Thoroughbreds. The maximal rate of lactate production (Δ Lȧmax) was about 35 mmol/litre. min for the polo ponies and 20 to 25 mmol/litre. min for the Standardbreds and the Thoroughbreds. Values for Δ Lamax and Δ Lȧmax were similar to those measured in human athletes after exhaustive work.

Δ Lȧmax increases with the speed (v) and can be described by the equation Δ Lȧ= a (v‐v1), where a is a proportionality constant representing the amount of lactate needed to cover a unit distance and v1 the theoretical speed at which Δ Lȧ= 0. v1 was highest for the Thoroughbreds and lowest for the polo ponies; this difference could be caused by the effect of training and/or to genetic differences among the different breeds of horses. v1 could be a useful index of the fitness of a horse following a training programme.
Integrated control ofStrongylus vulgarisinfection in horses using ivermectin
Authors: DUNSMORE J. D.
Published: April 2010

An attempt was made to control or eliminateStrongylus vulgarisfrom a closed group of three horses at pasture near Perth, Western Australia, by dosing with ivermectin on four occasions during the time of year when it was believed that environmental conditions would eliminate all the non‐parasitic stages of that species. At necropsy, five months after the last dose of anthelmintic and after continually grazing the same pastures, noS vulgarisor arterial lesions were found in those horses andS edentatus, Draschia megastomaandHabronemaspecies were also almost completely eliminated.
Effect of experimental vascular occlusion on small intestinal motility in ponies
Authors: DAVIES J. V. , GERRING E. L.
Published: April 2010

Small intestinal ischaemia is a cause of pain in man and horses. Occlusion of the vascular supply to Thiry loops in experimental ponies caused severe discomfort and loss of motility within a few minutes but these effects could not be reproduced by a similar procedure in intact gut preparations. However, embolisation of the mural vascular network produced ischaemia of the small intestine of anaesthetised ponies which led to a cessation of motility in the affected segments, though unaffected segments became hypermotile with a characteristic motility pattern. These results suggest the need for reappraisal of the classical theory of parasite‐induced damage to the cranial mesenteric artery as the cause of ischaemic bowel disease.
Equine leucocyte antigen system: Progress and potential
Authors: MATTHEWS SUSAN M. S.
Published: April 2010

Leucocyte antigens are cell‐surface glycoproteins, the structure of which is under the genetic control of a chromosome region called the major histocompatibility complex. Progress in the study of the equine leucocyte antigen (ELA) system has been achieved in two ways; first by the fact that the ELA system is intensively investigated in different laboratories all over the world and parallels can be drawn to the information gained from research in more extensively studied species, and secondly by the collaborative efforts of the participants in three international workshops. The potential applications of the ELA system and areas of further investigation are discussed.
Ultrastructural variations in the sweat glands of anhidrotic horses
Authors: JENKINSON D. McEWAN , MONTGOMERY I. , ELDER H. Y. , MASON D. K. , COLLINS E. A. , SNOW D. H.
Published: April 2010

The ultrastructure of sweat glands from the skin of free sweating horses was compared with that of glands from anhidrotic cases. Evidence of atrophied and abnormal sweat glands in the anhidrotic horses indicates that the condition involves progressive failure of the glandular mechanism of sweat production.
Serum bactericidal responses toStreptococcus equiof horses following infection or vaccination
Authors: TIMONEY J. F. , EGGERS DIANA
Published: April 2010

An indirect test based on horse blood was used to study bactericidal responses of the horse toStreptococcus equifollowing infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to 10 months after vaccination exhibited rapid and substantial increases in serum bactericidal activity. Groups of yearlings immunised with commercialS equivaccines consisting either of M protein or bacterin developed clinical strangles within six months of vaccination although the majority of the animals had exhibited strong serum bactericidal activity a few weeks before occurrence of the disease. Similarly, a group of seven yearling ponies hyperimmunised with experimental vaccine, rich in M protein, were found to be highly susceptible to an intranasal challenge of 5 × 108colony forming units ofS equi, although their sera exhibited strong bactericidal activity at the time of challenge. These observations suggest that the role of serum bactericidal antibody in protection of the horse against strangles has been overrated.
Regional blood flow changes in response to near maximal exercise in ponies: A review
Authors: PARKS CHRISTINE M. , MANOHAR MURLI
Published: April 2010

In recent years, increasing attention has been focused on the physiological responses of the horse to maximal exercise. Cardiovascular response in near maximally exercised galloping ponies (heart rate 225 ± 7 beats/min; whole body oxygen consumption 122 ± 12 ml/min/kg) comprised a marked increase in blood flow to the cerebellum, myocardium, diaphragm and the working muscles, while renal blood flow decreased precipitously. Cerebral and brainstem perfusion did not vary from resting values. Transmural homogeneity of myocardial blood flow persisted during near maximal exercise. It was reported that tachycardia of exercise contributed about one‐third of the total increment in left ventricular coronary blood flow. Considerable unutilised coronary vasodilator capacity was also demonstrated in near maximally exercised ponies and it was suggested that maximally exercising ponies were not limited from further exertion because of the coronary circulation.
Muscle fibre variation in the gluteus medius of the horse
Authors: BRUCE VIRGINIA , TUREK R. J.
Published: April 2010

The gluteus medius of two killed Thoroughbred horses were sampled along the muscle and across the muscle at four different depths. The distribution of fibre types in these two horses was assessed by staining cross sections of the muscle sample for ATPase. A non‐uniform distribution of fibre types was found within the gluteus medius in both horses and there was a significant increase in percentage of slow twitch (ST) fibres from the surface to the deeper regions of the muscle. The rate of increase, however, depended on the individual site along the muscle. Averages ranges from a low of 2.4 per cent ST fibres to a high of 64.5 per cent. This study shows that small biopsy samples of fibres are not necessarily representative of the whole muscle and that there is a need in subsequent studies to define precisely biopsy location.
Muscle fibre characteristics of active and inactive Standardbred horses
Authors: ESSÉN‐GUSTAVSSON BIRGITTA , LINDHOLM A.
Published: April 2010

Muscle biopsies were taken from the middle gluteus muscle of 36 Standardbred horses. Twelve of the horses were inactive, while 24 were actively trained and raced. Twelve of the trained horses were moderate performers, with a mean racing time of 1 min 21 secs per km (741 m/min) and the other 12 were excellent performers, with a mean racing time of 1 min 16 secs per km (789 m/min). The percentage and mean area of Type I fibres were similar in all three groups of horses. Marked differences were found among the subgroups of Type II fibres. The well‐trained horses had a higher proportion of Type IIA fibres and a lower proportion of the Type IIB (58 per cent IIA and 15 per cent IIB fibres in the excellent performers; 49 per cent IIA and 26 per cent IIB in the moderate performers) than the inactive horses (41 per cent IIA and 35 per cent IIB fibres). The mean area of Type II fibres was smaller in the muscle of the active horses (excellent performers: IIA, 3075 μm2; IIB, 3378 μm2) moderate performers: IIA, 3185 μm2; IIB, 4252 μm2) than in that of the inactive ones (IIA, 3714 μm2; IIB, 5935 μm2). Intramuscular substrates (glycogen and triglycerides) and the activities of enzymes used as markers for the glycolytic potential of the muscle seemed to be similar in the three groups of horses, although there were large interindividual variation. Citrate synthase activity, representing oxidative potential, was higher in the active horses (excellent performers 91.6 μmol/g/min; moderate performers 74.4 μmol/g/min) than in the inactive ones (54.4 μmol/g/min). These results demonstrate the critical dependence of racing performance on the rate of aerobic energy production in the locomotor muscles; because the horses with the best racing times had the highest IIA:IIB ratio, the smallest Type II fibre areas and the greatest oxidative potential in the muscle tissue.
Energy metabolism in relation to skeletal muscle fibre properties during treadmill exercise
Authors: VALBERG S. , ESSÉN‐GUSTAVSSON BIRGITTA , LINDHOLM A. , PERSSON S.
Published: April 2010

The skeletal muscle metabolism of horses with a wide range of cardiocirculatory capacities was studied during a standardised near‐maximal exercise test in relation to muscle fibre composition. Although the same amount of work was performed by all horses the amount of triglycerides and glycogen utilised and lactate accumulated differed widely. Both blood and muscle lactate accumulation were positively related to the amount of glycogen utilised. These factors were in turn positively associated with the percentage of Type IIB fibres and consequently negatively associated with the percentage of Type IIA fibres. The percentage of Type IIB fibres was negatively correlated to the activities of the oxidative enzymes citrate synthase and 3‐hydroxyacyl‐CoA‐dehydrogenase and positively associated with the lactate dehydrogenase activity. The results indicate that the horses with a high proportion of Type IIB fibres had a lower muscle oxidative capacity and were, therefore, for energy production, more dependent upon glycolysis with subsequent lactate accumulation than horses which had a high proportion of Type IIA fibres. The different metabolic properties of the muscle fibre types indicate that the pattern of muscle fibre recruitment could have a significant effect on intramuscular substrate utilisation.
BCG treatment of periocular sarcoid
Authors: LAVACH J. D. , SULLINS K. E. , ROBERTS S. M. , SEVERIN G. A. , WHEELER C. , LUEKER D. C.
Published: April 2010

Twenty‐six horses and five mules with periocular sarcoids were treated with intralesional injections of a purified bacillus of Calmette and Guerin (BCG) cell walls in oil suspension. All sarcoids were cured and the horses and mules remained free from recurrence of sarcoid during the two‐year follow‐up period.
Standardised technique for determining the centre of gravity of body and limb segments of horses
Authors: SPRIGINGS E. , LEACH D.
Published: April 2010

A standardised method of disarticulating the equine cadaver into 19 segments and determining the centre of gravity of each segment is described. The location of the segment centre of gravity and total body centre of gravity of three horses was determined using these methods. The mathematical procedure (algorithm) required for the determination of the total body centre of gravity from film analysis is presented.