bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SummaryBlood 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

SummaryAn 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

SummarySmall 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

SummaryLeucocyte 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

SummaryThe 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

SummaryAn 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

SummaryIn 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

SummaryThe 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

SummaryMuscle 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

SummaryThe 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

SummaryTwenty‐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

SummaryA 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.
Gentamicin dosage in foals aged one month and three months
Authors: BAGGOT J. DESMOND , LOVE DARIA N. , STEWART JENNIFER , RAUS J. 
Published: April 2010

SummaryThe absorption and disposition kinetics of gentamicin were compared at two dosage levels (2 and 4 mg/kg bodyweight [bwt]) in one‐ and three‐month‐old foals. Following intramuscular (im) injection of single 2 mg/kg bwt doses, the drug was absorbed rapidly and produced peak serum concentration (18.2 μ 5.3 ±g/ml, n = 8) at 30 mins. Much wider variations were associated with the amount of drug absorbed and the serum gentamicin concentrations after administration at the higher dosage level. The half‐life of gentamicin was similar in the one‐month‐old (3.7 ± 1.7 h, n = 8) and three‐month‐old (3.3 ± 0.8 h, n = 8) foals, and was independent of the dose. One‐month‐old foals did not appear to have a deficiency in renal excretion of gentamicin. The minimum inhibitory concentration of gentamicin for Corynebacterium equi and certain other equine bacterial isolates was less than 0.195 μg/ml. It was concluded that 2 mg/kg bwt administered by im injection at 8 to 12 h intervals, depending on the severity of the infection, could be recommended as the dose rate for treatment of systemic infections caused by microorganisms that are susceptible to gentamicin.
Temporary bilateral carotid artery occlusion as an aid to nasal surgery in the horse
Authors: WYN‐JONES G. , JONES R. S. , CHURCH S. 
Published: April 2010

SummaryOne of the major obstacles to successful intranasal surgery in the horse is haemorrhage, even minor interferences causing profuse bleeding. Conventional techniques for haemostasis are ineffective or inhibit the progress of the surgery. Temporary bilateral occlusion of the common carotid artery resulted in a substantial reduction in haemorrhage during intranasal surgery in five horses, with much improved visibility and facility of operation. The large contribution to the circle of Willis by the ventral spinal artery is believed to prevent cerebral ischaemia during this procedure. This paper describes the technique of temporary bilateral ligation of the common carotid artery and emphasises the importance of ancillary techniques such as packing of the nasal cavity and general postoperative management.
Comparison of the measurement of plasma testosterone and plasma oestrogens for the diagnosis of cryptorchidism in the horse
Authors: COX J. E. , REDHEAD PATRICIA H. , DAWSON FIONA E. 
Published: April 2010

SummaryThe results of performing 1720 blood tests for equine cryptorchidism are described. Using the paired sample human chorionic gonadotrophin (hCG) stimulation test and measuring testosterone, 6.7 per cent of tests did not give a clear result. If only the testosterone concentration in the pre‐hCG blood sample was used, this percentage rose to 14 per cent. The paired sample hCG stimulation test was 94.6 per cent accurate. A comparison was made between the paired hCG stimulation test and the measurement of conjugated oestrogen in a single sample. The latter did not give as many doubtfuls but gave false negatives in donkeys of all ages and in horses less than three years old. Measurement of conjugated oestrogen was found to be 96 per cent accurate when donkeys and young horses were excluded. It is, therefore, recommended as a simpler and more reliable test than the paired sample hCG test, but only in the older horse.
Synovial fluid and plasma kinetics of methylprednisolone and methylprednisolone acetate in horses following intra‐articular administration of methylprednisolone acetate
Authors: AUTEFAGE A. , ALVINERIE M. , TOUTAIN P. L. 
Published: April 2010

SummarySynovial fluid and plasma kinetics of methylprednisolone acetate (MPA) and methylprednisolone (MP) after a single intra‐articular administration of MPA at a therapeutic dose (111 mgin toto) was measured in five horses. MPA was detected in synovial fluid for two to six days post injection and MP, which results from synovial MPA hydrolysis, was present in pharmacologically significant concentrations for 4.8 to 39 days, depending on the horse. MPA synovial concentration was maximal (289 ± 284 μg/ml) at the first sampling time (2 h after administration) and MP synovial concentration was maximal (from 58.9 to 379.5 μg/ml) at the first or second sampling time (2 to 10 h after administration). Thereafter, both MP and MPA declined rapidly. From time of administration to about five days later, MP synovial fluid concentration fell progressively with a half‐time of 9.95 h. Subsequently, the MP synovial fluid concentration decreased more slowly with an apparent half‐time of 115 h. During the first 24 h following MPA administration, trace amounts of MP (less than 5 ng/ml) were detected in plasma. Plasma hydrocortisone levels were depressed for three to four days after administration but adrenal responsiveness to adrenocorticotrophic hormone tests remained unaffected.
Radiographic assessment of navicular bones, based on changes in the distal nutrient foramina
Authors: MACGREGOR CHRISTINA M. 
Published: April 2010

SummaryRadiographic examination of the navicular bones of 258 horses was carried out. Of these 258 horses, 83 were sound (Group A), 151 had been diagnosed clinically as having navicular disease (Group B), and 24 had a forefoot lameness of unknown aetiology (Group C). Seven basic shapes of distal nutrient foramina were identified from these radiographs. A scoring system was then developed based on these different types of distal nutrient foramina. When this scoring system was applied to the radiographs of the 258 horses examined significant differences were found between the mean navicular scores of the horses in Groups A, B and C. It is considered that this navicular scoring system could be very useful for comparing radiographs of the navicular bones of different horses and recording serial radiographs of navicular bones of the same horse.
Review of large intestinal motility and mechanisms of impaction in the horse
Authors: SELLERS A. F. , LOWE J. E. 
Published: April 2010

SummaryThe large intestine has distinct motility patterns which include non‐rhythmic haustral kneading of ingesta and stronger rhythmic retropulsive and propulsive contractions which move ingesta along the tract. A variable site electrical pacemaker exists at the pelvic flexure where the strong rhythmic contractions begin. The large intestine can contract adequately with only the intrinsic nerve supply intact. Neurotransmitters have profound effects on large intestinal activity.
Incidence, diagnosis and treatment of postoperative complications in colic cases
Authors: HUNT JUDITH M. , EDWARDS G. B. , CLARKE KATHY W. 
Published: April 2010

SummaryA survey of 259 surgical colic cases revealed that over 50 per cent of fatalities occurred in the postoperative period. Post‐operative ileus and circulatory/endotoxaemic shock accounted for 70 per cent of these deaths. Other less important complications were salmonellosis, long bone fracture, adhesions, haemorrhage, laminitis, wound infection and ischaemic muscle damage. Close monitoring of postoperative progress is necessary to enable early diagnosis and treatment. Recent developments in understanding of the pathophysiology of endotoxic shock and ileus may lead to more successful treatment regimes. The possibilities include the use of cyclo‐oxygenase inhibitors, anti‐endotoxin hyperimmune serum and dopamine antagonists.
Haemostatic abnormalities in horses with colic — Their prognostic value
Authors: JOHNSTONE I. B. , CRANE S. 
Published: April 2010

SummaryThe incidence and nature of coagulation abnormalities in horses presented with colic and the possible prognostic value of these abnormalities was investigated. A coagulogram was performed on each of 24 adult Thoroughbred or Standardbred horses. A coagulogram consisted of measurements of eight parameters; platelet count, plasma fibrinogen, plasma antithrombin III (AT), partial thromboplastin time (PTT), prothrombin time (PT), thrombin clotting time (TCT), soluble fibrin monomer (SFM) and fibrin‐fibrinogen degradation products (FDP). Retrospective determination of the cause of the colic and outcome (survival vs non‐survival) was carried out. All patients examined had at least one abnormal parameter with the frequency being: Increased SFM 67 per cent; prolonged PTT 63 per cent; prolonged TCT 50 per cent; elevated plasma fibrinogen 46 per cent; reduced platelet count 29 per cent; reduced plasma AT 29 per cent; prolonged PT 25 per cent; and elevated serum FDP 21 per cent. When survivor and non‐survivor groups were compared there was little difference in the frequency of abnormalities such as elevated SFM, elevated fibrinogen and prolonged PTT. The abnormalities which had the greatest frequency difference between non‐survivors and survivors, and therefore the greatest prognostic value, were decreased AT > prolonged TCT = prolonged PT > elevated FDP > reduced platelet count. The frequency of these abnormalities in non‐survivors compared to survivors was 8.6:1, 7.1:1, 5.7:1 and 3.6:1, respectively. The average number of abnormal parameters in non‐survivors (five) was significantly greater than in survivors (two).
Colitis: Differential diagnosis and treatment
Authors: WHITLOCK R. H. 
Published: April 2010

SummaryEquine colitis characterised by diarrhoea and/or pain may be caused by a wide variety of bacterial, viral, protozoal agents and toxins. The causative agent of Potomac horse fever,Ehrlichia risticii, is the most recently recognised cause of colitis. Salmonella, the agent typically associated with colitis, also causes abdominal pain (colic) of variable intensity. Acute colitis is also caused by colitis X, various antibiotics, endotoxic shock and peritonitis caused by arterial infarction. The principles of therapy for each of these, together with means of differential diagnosis, are presented.
Gastric ulceration in mature Thoroughbred horses
Authors: HAMMOND C. J. , MASON D. K. , WATKINS K. L. 
Published: April 2010

SummaryRoutine post mortem examination of 195 Thoroughbreds in Hong Kong revealed that 66 per cent suffered from gastric ulceration. Racehorses killed straight out of training suffered a significantly greater incidence of ulceration (80 per cent) than those having been retired for a month or more (52 per cent). The macroscopic findings post mortem enabled a classification of equine gastric ulceration to be suggested (Types 1, 2, 3), according to severity. Severe lesions (Types 2 and 3) were present in 45 per cent of horses put down from training and 5 per cent of retired horses. This difference was significant. Lesions appeared to be chronically progressive during training, but to regress during retirement. The observed difference of gastric ulceration between the two groups of horses was similar for different age groups.