bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proximal suspensory desmitis: clinical, ultrasonographic and radiographic features
Authors: DYSON SUE 
Published: April 2010

SummaryClinical, ultrasonographic and radiographic features of proximal suspensory desmitis in the forelimb and the hindlimb are described. Acute cases may present with slight, localised, oedematous swelling, heat, distension of the medial palmar (plantar) vein and/or pain, whereas chronic cases or those rested immediately after onset of lameness usually have no detectable clinical signs suggestive of the source of pain. In these cases local analgesia is required to identify pain in the proximal metacarpal (metatarsal) region. Transverse ultrasonographic images of the suspensory ligament usually yield the most information and a variety of abnormalities of the proximal suspensory ligament have been identified including i) enlargement ii) poor definition of one or more of the margins of the suspensory ligament, especially dorsally iii) a well circumscribed, central hypoechoic area iv) one or more poorly defined hypoechoic areas, central or more peripheral v) a larger area of diffuse decrease in echogenicity (such lesions were seen most commonly in the hindlimb and appeared to warrant a more guarded prognosis than focal lesions). Radiographic abnormalities were identified in hindlimbs more often than in forelimbs and were usually seen in a dorsopalmar (dorsoplantar) view, and/or a lateromedial projection. Radiographic abnormalities included sclerosis of the trabeculae, a change in orientation of the trabeculae and entheseophyte formation. The most extensive radiographic abnormalities were seen together with an ultrasonographic type v lesion. The prognosis for return to full athletic function and sustained future soundness was better for forelimbs than hindlimbs, especially if the lesion, identified ultrasonographically, resolved.
Low dose calcium heparin in horses: plasma heparin concentrations, effects on red blood cell mass and on coagulation variables
Authors: GERHARDS H. 
Published: April 2010

SummaryLow dose calcium heparin was administered subcutaneously at 12 hourly intervals to six healthy horses at an initial dose of 150 iu of heparin/kg bodyweight (bwt) and at a maintenance dose of 120 iu/kg bwt. All injections were given at 0900 and 2100 h. Blood samples for monitoring plasma heparin concentrations were obtained prior to, at 2 hourly intervals for 84 h (treatment period), and at Hours 24, 32, 48 and 96 of the control period. Blood samples for monitoring red blood cell (RBC) mass, plasma antithrombin III activity (AT III), activated partial thromboplastin time (APTT), and thrombin time (TT) were taken at 8 hourly intervals during the treatment period and at all of the Control Period Hours. Mean plasma heparin concentrations increased significantly (P<0.01) from 2 h after the first to 32 h after the last (seventh) injection. Mean values corresponding to the desired range of heparin in plasma (0.05 to 0.20 iu/ml) were achieved at 21 h after initiation of heparin treatment and were maintained during the following 81 h. Great individual variations in the sensitivity to heparin among horses, cumulation of heparin in plasma with prolonged administration and a marked circadian periodicity in the disposition of heparin affected actually measured plasma heparin values. A chronodiagram revealed peak values around 1300 h, trough values around 0500 h. The peak‐trough difference amounted to about 50 per cent. Increasing plasma heparin concentrations were associated with erratic prolongations of mean APTT and TT values. The AT III curve was not affected significantly. Low dose heparin treatment induced significant RBC mass depletion by about 30 to 35 per cent and agglutination of erythrocytesin vitroin healthy horses. In a splenectomised, otherwise healthy pony, given large doses of heparin, only a minor decrease in the RBC mass was evident. The RBC indices of the horses and the pony were not significantly altered. Four days after cessation of heparin administrations all values were within the baseline range. The agglutination could be reversed by adding trypsin to the sample, but not by neutralising heparin in the sample or by incubation of washed, agglutinated cells with plasma from an untreated horse. Incubation of washed erythrocytes from an untreated horse with plasma from a heparinised horse did not produce RBC agglutination. Other than some degree of pale mucous membranes no clinically detectable signs were attributable to the heparin‐induced agglutination‐anaemia phenomenon. The outlined heparin regimen may be useful for efficacious low‐dose heparin treatment in horses.
Assessment of an immunoturbidimetric method for measuring equine serum haptoglobin concentrations
Authors: KENT JOYCE E. , GOODALL JANE 
Published: April 2010

SummarySerum haptoglobin was measured by immunoturbidity in Thoroughbreds stabled in three Newmarket yards for nine months. The mean serum haptoglobin value for horses housed in Stable 1 was 1.43 ± 0.68 g/litre, similar to values in grazing adult ponies. The mean monthly haptoglobin values remained constant. For horses in Stable 2 there was an increase in serum haptoglobin values in June and July whereas, in Stable 3, the increases early in the training season were associated with an increase in serum viral titres. In equine serum, haptoglobin values estimated in g/litre by immunoturbidimetry were twice the haemoglobin binding capacity (HbBC). The correlation coefficient, between the methods, exceeded 0.96. Surgical interference caused a 2‐ to 3‐fold increase in serum haptoglobin, with levels peaking between three and five days post surgery. The concomitant presence of haematomata following surgical interference (castration) resulted in the disappearance of haptoglobin from the circulation. There was no significant increase in serum haptoglobin levels following vaccination of Thoroughbreds against influenza and tetanus. However inhalation of influenza virus by vaccinated and non‐vaccinated ponies resulted in a 2‐ to 3‐ fold increase in both groups of ponies, peaking seven to 10 days post infection. Serum haptoglobin proved to be a useful indicator of infection/ inflammation and haemolytic disease in the horse and could be used to monitor the health status of stabled Thoroughbreds.
Antithrombotic actions of aspirin in the horse
Authors: CAMBRIDGE H. , LEES P. , HOOKE R. E. , RUSSELL C. S. 
Published: April 2010

SummaryThe antithrombotic effects of aspirin at two dose rates (4 mg/kg and 12 mg/kg bodyweight [bwt]) were evaluated in normal, healthy ponies by measuring template bleeding time. Inhibition of platelet aggregation in response to adenosine diphosphate (ADP) and collagen was evaluated and cyclo‐oxygenase activity was monitored by radioimmunoassay of thromboxane B2(TXB2), the stable metabolite of thromboxane A2(TXA2). TXB2was measured in serum and platelet rich plasma. Bleeding time was prolonged significantly until 48 h after treatment at 12 mg/kg bwt and until 4 h at the lower dose rate. Synthesis of TXB2and collagen induced aggregation were diminished for much greater periods with similar results at each of the dose rates. The prolonged effects of aspirin on platelet function occurred in spite of a very short plasma half‐life of aspirin, because of its irreversible action on platelet cyclo‐oxygenase. The results show that low dose aspirin has a potential role in antithrombotic therapy in horses although the relationship between skin bleeding time in normal horses and improvement of clinical conditions requires further research and evaluation in clinical trials. TXB2measurement appears to overestimate the duration of antithrombotic effects of aspirinin vivo.
Clinical evaluation of poor performance in the racehorse: the results of 275 evaluations
Authors: MORRIS ELISABETH A. , SEEHERMAN H. J. 
Published: April 2010

SummaryA clinical sports medicine evaluation was applied to 275 racehorses with a history of poor racing performance. The poor performance evaluation included a) general physical examination and basic laboratory screening; b) respiratory examination including auscultation, thoracic radiographs, ventilation‐perfusion lung scintigraphy and upper airway endoscopy at rest and during maximal treadmill exercise c) examination of the musculoskeletal system including lameness examination, video gait analysis at high speed, post exercise serum chemistry to identify obvious as well as sub‐clinical myopathies, high detail radiography and nuclear scintigraphy; d) cardiac examination including auscultation, electrocardiographic analysis during strenuous exercise and, when indicated, echocardiography; and e) a standardised exercise stress test entailing the measurement of oxygen consumption, carbon dioxide production, venous blood lactate concentration and heart rate during sequentially increasing running speeds on the high speed treadmill. The choice of diagnostic methodologies utilised were tailored to each individual in order to determine most efficiently the abnormalities contributing to inadequate racing performance. The results of this clinical evaluation showed that 1) many of the diagnoses were subtle requiring the use of sophisticated diagnostic equipment including scintigraphy and dynamic evaluation of the horse exercising on the high speed treadmill and 2) 84 per cent of the horses were diagnosed as suffering from more than one problem leading to the supposition that inadequate athletic performance is often caused by a constellation of abnormalities requiring a comprehensive approach to diagnosing decreased athletic capability.
Characterisation and distribution of epidermal growth factor receptors in equine hoof wall laminar tissue: comparison of normal horses and horses affected with chronic laminitis
Authors: GROSENBAUGH D. A. , HOOD D. M. , AMOSS M. S. , WILLIAMS J. D. 
Published: April 2010

SummaryEpidermal growth factor (EGF) receptors were detected in plasma membrane preparations of equine hoof wall laminar tissue at concentrations comparable to that of equine liver. Scatchard analysis of the equilibrium binding data suggested the presence of two classes of EGF binding sites in most of the controls (plasma membranes from clinically normal horses); a high‐affinity class and a more numerous low‐affinity class. The dissociation constant of the low‐affinity class of EGF‐specific receptors (KD=1 × 10−9M) is in reasonable agreement with other values established for the EGF receptor. The variability between individual estimates for the KDof the high‐affinity receptor class precluded an accurate estimate for those sites. A possible explanation is discussed. The high‐affinity binding sites were uniformly absent in plasma membranes prepared from horses affected by chronic laminitis. Autoradiographic analysis localised the EGF receptors primarily to the secondary epidermal laminae, with an apparent greater density over the proliferative basal keratinocytes. Little label was associated with the dermal or the keratinised primary epidermal laminae. Tissue from horses with chronic laminitis had EGF receptors located uniformly over the hyperplastic epidermal keratinocytes. These data suggest that an EGF‐mediated response may be involved in the hyperproliferative response that is characteristic of chronic laminitis.
Exercise induced hormonal and metabolic changes in Thoroughbred horses: effects of conditioning and acepromazine
Authors: FREESTONE J. F. , WOLFSHEIMER K. J. , KAMERLING S. G. , CHURCH G. , HAMRA J. , BAGWELL C. 
Published: April 2010

SummaryNine Thoroughbred horses were assessed to determine the normal response of insulin, glucose, Cortisol, plasma potassium (K) and erythrocyte K through conditioning and to exercise over 400 and 1,000 m. In addition, adrenaline, noradrenaline, Cortisol, plasma K, erythrocyte K and L‐lactate concentrations were evaluated in response to maximal exercise with and without the administration of acepromazine. Conditioning caused no obvious trends in plasma K, erythrocyte K, insulin or glucose concentration. Serum Cortisol increased (P < 0.05) from the initial sample at Week 1 to Weeks 4 and 5 (attributed to a response to training), and then decreased. During conditioning, three horses had low erythrocyte K concentrations (< 89.3 mmol/litre). Further work is needed to define the significance of low erythrocyte K concentrations in the performance horse. In all tests maximal exercise increased plasma K, glucose and Cortisol concentrations, whereas insulin and erythrocyte K concentrations decreased. Thirty minutes following exercise, plasma K and erythrocyte K concentrations returned to resting values, whereas glucose and Cortisol concentrations continued to increase and the insulin concentration also was increased. The magnitude of the changes varied for pre‐conditioned vs post‐conditioned exercise tests and the duration of exercise. The administration of acepromazine prior to exercise over 1,000 m failed to alter the circulating noradrenaline and adrenaline concentrations in anticipation of exercise or 2 mins following exercise. Acepromazine administration, however, did cause lower L‐lactate concentration 2 mins (P < 0.03) and 30 mins (P ≤ 0.005) following exercise. Also, erythrocyte K showed a delayed return to baseline levels at 30 mins post exercise. Further evaluation of these trends may help explain the beneficial role acepromazine plays in limiting signs of exertional rhabdomyolysis when administered prior to exercise.
A comparison of two techniques for arthrocentesis of the equine metacarpophalangeal joint
Authors: MISHEFF MARTHA M. , STOVER SUSAN M. 
Published: April 2010

SummaryBecause arthrocentesis of the metacarpophalangeal joint through the proximal palmar pouch may induce synovial haemorrhage, this study evaluated arthrocentesis through the lateral collateral sesamoidean ligament. The proximal palmar pouch and collateral sesamoidean ligament approaches were used in contralateral forelimbs to obtain paired initial synovial fluid samples from 16 horses 12 to 15 h before being killed. Synovial fluid samples also were collected from the same joints at necropsy and the subcutis, synovium and articular cartilage were evaluated. Metacarpophalangeal joint arthrocentesis through the collateral sesamoidean ligament yielded fewer haemorrhagic synovial fluid samples with less subcutaneous and synovial inflammation, and also yielded 2 ml of synovial fluid more often than arthrocentesis through the proximal palmar pouch.
Use of DNA fingerprinting in paternity analysis of closely‐related Exmoor ponies
Authors: HOPKINS B. , O'CONNELL F. M. , HOPKINS J. 
Published: April 2010

SummaryDNA fingerprinting techniques were used to try to resolve the parentage of an Exmoor pony foal. Three young Exmoor ponies, one female and two males, shared a paddock and the female subsequently became pregnant. The two possible sires were three‐quarter siblings and were also half‐siblings to the dam. Southern hybridisation of Exmoor pony DNA with human mini‐satellite probes resolved the disputed parentage in spite of the fact that there was a 70 per cent band share between the individuals involved. Colt M6 was 2.06 times more likely to be the father than an uncle, and Colt M3 was 477 times more likely to be an uncle than the father.
Fusion of the distal intertarsal and tarsometatarsal joints in the horse using intraarticular sodium monoiodoacetate
Authors: BOHANON T. C. , SCHNEIDER R. K. , WEISBRODE S. E. 
Published: April 2010

SummarySix normal horses received 3 intra‐articular injections of sodium monoiodoacetate (MIA) in the distal intertarsal (DIT) and tarsometatarsal (TMT) joints of one hindlimb. Injections were at three week intervals, and post injection pain was controlled with routine administration of phenylbutazone for five days following each injection. All horses underwent a gradually increasing exercise programme consisting of walking and trotting beginning one week after the first injection and continuing for 24 weeks. All treated joints showed increasingly severe radiographic evidence of degenerative joint disease with time. Clinical signs were mild or absent during exercise. All treated joints showed radiographic and histological evidence of fusion 24 weeks after the first injection. Amount of radiographic fusion ranged from 54.49 per cent to 88.64 per cent of the joint space. Histologically, the joint space that appeared radiographically fused was filled mainly with woven and lamellar bone. Fibrocartilage and fibrous tissue was seen frequently in the transition between fused and unfused areas. Articular cartilage in unfused areas was thin, fibrillated, hypocellular and histochemically showed diminished proteoglycan content. Existing joint space was filled with fibrin and necrotic, acellular chondroid matrix. We conclude that MIA will produce fusion of the DIT and TMT joints of normal horses in 24 weeks, and may offer a relatively easy, inexpensive and non‐invasive treatment for distal tarsal osteoarthritis in the horse.
Whole blood re‐calcification time in equine colic
Authors: HENRY MICHELLE M. , MOORE J. N. 
Published: April 2010

SummaryWhole blood re‐calcification times were evaluated as a measure of endotoxin‐associated coagulopathy in horses. First, the effects of endotoxin concentration and duration ofin vitroincubation of citrated whole blood with endotoxin on the whole blood re‐calcification time of blood collected from healthy horses were determined. Increasing concentrations or incubation times of endotoxin accelerated the whole blood re‐calcification time. This effect was attributed mainly to increased monocyte thromboplastin activity. Second, whole blood re‐calcification time, a clotting profile, plasma factor VII activity and plasma endotoxin concentration on blood samples obtained from 35 equine colic patients and 10 healthy horses were determined. Compared with healthy horses, colic patients had a longer mean whole blood re‐calcification and prothrombin time, lower per cent factor VII activity and higher mean fibrin degradation products concentration. Within the colic patient group, horses that did not survive had detectable endotoxin in plasma, longer whole blood re‐calcification and prothrombin times, and lower plasma factor VII activity, compared with colic patients that survived. These data indicate that colic patients with endotoxaemia experience hypercoagulable states, followed by consumptive coagulopathy. Although the cause of endotoxin‐associated coagulopathy is likely multi‐factorial, increased expression of monocyte thromboplastin activity may be involved in the pathogenesis of coagulopathy. The whole blood re‐calcification time is a simple, fast and inexpensive way to detect coagulopathy during endotoxaemia and determine the prognosis for survival.
Changes in some haematological and metabolic indices in young horses during the first year of jump‐training
Authors: JABLONSKA EWA M. , ZIOLKOWSKA SWIETLANA M. , GILL J. , SZYKULA R. , FAFF J. 
Published: April 2010

SummaryEffects of an 18 min exercise test, on three separate occasions during a one year jump‐training programme, was studied in seven horses. Determinations were carried out on venous blood for packed cell volume, haemoglobin, total protein, lactate and pyruvate, glucose, free fatty acids, insulin, glucagon, blood gases, bicarbonate, pH, aldolase, aspartate aminotransferase and alanine amino‐transferase. Exercise caused a slight increase in lactate and pyruvate, total protein, aldolase, alanine aminotransferase, pO2, bicarbonate and pH. Glucose, free fatty acids and pCO2levels decreased. Training caused no significant difference in these changes. However, during the year, increases in lactate and decreases in pH (resting levels) were observed.
A comparative study of normal equine populations and those with grass sickness (dysautonomia) in eastern Scotland
Authors: DOXEY D. L. , GILMOUR J. S. , MILNE E. M. 
Published: April 2010

SummaryA retrospective survey was made of premises in eastern Scotland on which at least two cases of grass sickness had occurred between 1970 and 1987. For comparison, a further survey of 49 equine establishments, on which no grass sickness had been recorded, was conducted from 1986 to 1988. The results indicated that younger animals are more susceptible, especially those in good physical condition grazing full‐time in the spring or early summer. Movement to new grazing increases the risk of grass sickness and identifiable stress may contribute. The nature of the establishment governed the animals' condition during the summer, but it did not appear to influence the prevalence of grass sickness. However, riding schools and livery establishments which experienced the disease kept, on average, significantly more animals than unaffected premises of the same type. No relationship was found between supplementary feeding or stage of pasture growth and grass sickness. The results of the survey support the hypothesis that the causal agent of grass sickness is associated with grazing but multiple factors may influence the expression of illness.
Osteomyelitis of the axial border of the proximal sesamoid bones in seven horses
Authors: WISNER E. R. , O'BRIEN T. R. , POOL R. R. , PASCOE J. R. , KOBLICK P. D. , HORNOFF W. J. , POULOS P. W. 
Published: April 2010

SummaryDestructive lesions of the axial region of the proximal sesamoid bones were identified by radiography in eight fetlocks and seven lame adult horses. Lameness ranged from 2 to 5 (mean 4; scale 1 to 5) at the time of examination, with a duration of 10 days to two years (mean 5.6 months). Destructive lesions involved both proximal sesamoid bones when examined radiographically and were situated primarily at the level of the mid‐body and apical region of the axial borders. Some lesions were cystic, whereas others eroded the axial border more diffusely. Scintigraphy revealed markedly increased activity within the proximal sesamoid bones of the clinically lame limb of four of the five horses examined. In four horses, post mortem computed tomography revealed axial border bone destruction and cavitary lesions within cancellous bone of affected proximal sesamoid bones. Lesions seen by computed tomography were larger than those identified on radiographic examination. Cavitary lesions not seen radiographically were identified in the proximal sesamoid bones of two clinically unaffected fetlocks examined for comparison in two of the seven horses. Evidence of acute, subacute or chronic/reparative osteomyelitis of the axial region of the proximal sesamoid bones was seen in the 10 fetlocks identified as abnormal from radiography or computed tomography. Also, three horses had septic synovitis of the flexor sheath of the clinically affected limb; of these, two had septic arthritis of the fetlock joint.