bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study of an electrodiagnostic technique for the evaluation of equine recurrent laryngeal neuropathy
Authors: HAWE C. , DIXON P. M. , MAYHEW I. G. 
Published: April 2007

SummaryThe electrodiagnostic measurement of the thoracolaryngeal reflex (TLR) (‘slap test’) latency was compared to 5 other diagnostic techniques used for evaluation of laryngeal function, namely laryngeal muscle palpation, resting and immediately postexercise endoscopic examinations, and palpable and endoscopic responses to the TLR. Compared to resting endoscopy, the electrodiagnostic measurement of TLR latency was not found to be an accurate test for the evaluation of recurrent laryngeal neuropathy (RLN), nor was laryngeal muscle palpation or the endoscopic response to the TLR. Twenty‐five (71%) of 35 Clydesdale horses examined were affected by RLN; 16 (46%) had mild, 5 (14%) moderate, 3 (9%) severe hemiparesis and 1 (3%) had total laryngeal paralysis. Within these 35 horses, physical traits such as height orneck length did not correlate with the incidence or severity of RLN. Ten control ponies showed no evidence of abnormal laryngeal function.
Plasma pharmacokinetics and faecal excretion of ivermectin, doramectin and moxidectin following oral administration in horses
Authors: GOKBULUT C. , NOLAN A. M. , MCKELLAR Q. A. 
Published: April 2007

SummaryThe present study was carried out to investigate whether the pharmacokinetics of avermectins or a milbemycin could explain their known or predicted efficacy in the horse.The avermectins, ivermectin (IVM) and doramectin (DRM), and the milbemycin, moxidectin (MXD), were each administered orally to horses at 200 μg/kg bwt. Blood and faecal samples were collected at predetermined times over 80 days (197 days for MXD) and 30 days, respectively, and plasma pharmacokinetics and faecal excretion determined. Maximum plasma concentrations (Cmax) (IVM: 21.4 ng/ml; DRM: 21.3 ng/ml; MXD: 30.1 ng/ml) were obtained at (tmax) 7.9 h (IVM), 8 h (DRM) and 7.9 h (MXD). The area underthe concentration time curve (AUC) of MXD (92.8 ng.day/ml) was significantly larger than that of IVM (46.1 ng.day/ml) but not of DRM (53.3 ng.day/ml) and mean residence time of MXD (17.5 days) was significantly longer than that of either avermectin, while that of DRM (3 days) was significantly longer than that of IVM (2.3 days). The highest (dry weight) faecal concentrations (IVM: 19.5 μg/g; DRM: 20.5 μg/g; MXD: 16.6 μg/g) were detected at 24 h for all molecules and each compound was detected (≥ 0.05 μg/g) in faeces between 8 h and 8 days following administration.The avermectins and milbemycin with longer residence times may have extended prophylactic activity in horses and may be more effective against emerging and maturing cyathostomes during therapy. This will be dependent upon the relative potency of the drugs and should be confirmed in efficacy studies.
Effects of intravenous lidocaine overdose on cardiac electrical activity and blood pressure in the horse
Authors: MEYER G. A. , LIN H. C. , HANSON R. R. , HAYES T. L. 
Published: April 2007

SummaryThis study aimed to identify blood serum lidocaine concentrations in the horse which resulted in clinical signs of intoxication, and to document the effects of toxic levels on the cardiovascular and cardiopulmonary systems. Nineteen clinically normal mature horses of mixed breed, age and sex were observed. Lidocaine administration was initiated in each subject with an i.v. loading dose of 1.5 mg/kg bwt and followed by continuous infusion of 0.3 mg/kg bwt/min until clinical signs of intoxication were observed. Intoxication was defined as the development of skeletal muscle tremors. Prior to administration of lidocaine, blood samples for lidocaine analysis, heart rate, mean arterial blood pressure, systolic blood pressure, diastolic blood pressure, respiratory rate and electrocardiographic (ECG) data were collected. After recording baseline data, repeat data were collected at 5 min intervals until signs of intoxication were observed.The range of serum lidocaine concentrations at which the clinical signs of intoxication were observed was 1.85–4.53 μg/ml (mean ± s.d. 3.24 ± 0.74 μg/ml).Statistically significant changes in P wave duration, P‐R interval, R‐R interval and Q‐T interval were observed in comparison to control values, as a result of lidocaine administration. These changes in ECG values did not fall outside published normal values and were not clinically significant. Heart rate, blood pressures and respiratory rates were unchanged from control values. This study establishes toxic serum lidocaine levels in the horse, and demonstrates that there were no clinically significant cardiovascular effects with serum lidocaine concentrations less than those required to produce signs of toxicity.
Wedge‐shaped conformation of the dorsolateral aspect of the third tarsal bone in the Thoroughbred racehorse is associated with development of slab fractures in this site
Authors: BAIRD D. H. , PILSWORTH R. C. 
Published: April 2007

SummaryAnecdotal evidence suggested that many cases of third tarsal bone (T3) fracture encountered clinically were associated with an abnormal shape to this bone. The radiographs of 10 normal horses and 10 horses affected with slab fracture of T3 were therefore examined to ascertain if any pre‐existent radiological abnormality was present in cases of fracture. Measurement of the maximum and minimum width between the proximal and distal articular surfaces of the dorsolateral aspect of this bone was carried out on a standardised dorso‐50° medial‐palmarolateral radiographic projection of the tarsus of each horse. To avoid artefacts produced by possible image magnification, ratios of these values were used for comparison between horses. The results showed that wedge shaped conformation of T3, in which the articular surfaces of the bone converge and then diverge again on the dorsolateral aspect, was over‐represented in the population of horses sustaining T3 fracture when compared to controls. This information may be important in making judgements on the suitability of horses during prepurchase examination for racing.
Factors influencing blood flow in the equine digit and their effect on uptake of 99m technetium methylene diphosphonate into bone
Authors: DYSON S. , LAKHANI K. , WOOD J. 
Published: April 2007

SummaryIt was hypothesised that exercise may promote perfusion of the distal part of the limbs and enhance uptake of radiopharmaceutical into bone, but bandaging and lameness would have no effect. Two hundred and two horses undergoing routine nuclear scintigraphic examination for assessment of lameness or poor performance between November 1998 and November 1999 were assigned randomly to one of 4 groups: no bandages and no exercise (NB/NE); bandages and no exercise (B/NE); no bandages and exercise (NB/E); bandages and exercise (B/E). In the bandage groups, the distal forelimbs were bandaged for at least 16 h prior to injection of radiopharmaceutical. In the exercise groups, horses were lunged for 15 min at trot and canter prior to injection. Quantitative values for perfusion of the front feet and uptake of the radiopharmaceutical into the bones of the distal limb were obtained from scintigraphic measurements during the vascularand bone phases of radiopharmaceutical distribution. Perfusion of the front feet was classified as good in 60% of limbs, reduced in 21% and poor in 19%. There was a strong positive relationship between exercise and both perfusion of the front feet and uptake of the radiopharmaceutical into bone. Bandaging had no effect. There was a relationship between environmental temperature and both perfusion and uptake of the radiopharmaceutical into bone. Estimation of foot surface temperature using thermography was helpful in predicting perfusion of the distal limbs. There was no relationship between lameness and uptake of the radiopharmaceutical into bone. It is therefore recommended that, whenever possible, horses are exercised for 15 min prior to injection of radiopharmaceutical if nuclear scintigraphy of the distal parts of the limb is to be performed.
Systemic antibodies to Clostridium botulinum type C: do they protect horses from grass sickness (dysautonomia)?
Authors: HUNTER L. C. , POXTON I. R. 
Published: April 2007

SummaryThe aetiology of equine grass sickness (EGS) is still unknown. There is increasing evidence that toxicoinfection with Clostridium botulinum type C is involved. Epidemiological evidence shows that resistance to EGS can occur in older horses and those that have been on a particular pasture for longer or have been in prior contact with the disease. This resistance may be in the form of an immune response to the aetiological agent. Levels of systemic antibodies to the surface antigens of C. botulinum type C (using the closely related and safe C. novyi type A as a phenotypic marker) and to the botulinum type C neurotoxin (BoNT/C) were investigated in horses with and without EGS.Horses with grass sickness were found to have significantly lower levels of systemic IgG to both surface antigens and BoNT/C. Horses with low levels of systemic immunity to these antigens may be more susceptible to developing EGS. There were no significant differences in antibody levels between the different categories of EGS, suggesting systemic immunity to C. botulinum type C does not play a significant role in influencing the severity of the disease. However, horses that had been in contact with EGS or that were grazing land where it had occurred frequently in the past had significantly higher antibody levels to these antigens. These horses may have been exposed to subclinical doses of C. botulinum type C and BoNT/C, resulting in the production of a protective immune response against the putative aetiological agent. This finding is of potential significance for the prospect of prevention of EGS by vaccination against C. botulinum type C.
Effect of romifidine on gastrointestinal motility, assessed by transrectal ultrasonography
Authors: FREEMAN S. L. , ENGLAND G. C. W. 
Published: April 2007

SummaryA technique of transrectal ultrasonography was developed to investigate the effects of romifidine 80 and 120 μg/kg bwt on intestinal motility in the horse. Motility of the small intestine, caecum and left ventral colon were assessed following injection of romifidine and a saline control, using a blinded, cross‐over study design in 6 horses. Measurements were taken at 15, 30, 60, 120, 180 and 240 min after drug administration. There was a slight nonsignificant decrease in motility in the control group over the 4 h study period. Both doses of romifidine produced a marked decrease in gastrointestinal motility and were associated with the presence of reduced (nonpropulsive) contractions. Transrectal ultrasonography proved suitable for monitoring changes in the type and frequency of intestinal motility in the horse.
Application of a constant blood withdrawal method in equine exercise physiology studies
Authors: BARAGLI P. , TEDESCHI D. , GATTA D. , MARTELLI F. , SIGHIERI C. 
Published: April 2007

SummaryThe aim of the present study was to test a constant blood withdrawal method (CBWM) to collect blood samples from horses during treadmill exercise. CBWM was performed in 4 Standardbreds and 5 Haflinger horses. A peristaltic pump was used to control blood aspiration from an i.v. catheter via an extension line. Blood was collected using an automatic fractions collector, with a constant delay time between the drawing of blood and sample collection. Blood withdrawal using CBWM was made during a treadmill standardised exercise test (SET). A blood flow of 12 ml/min was used and samples collected every 60 s during the entire period of exercise. The volume of blood collected in each sample tube was 12.1 ± 0.2 ml, with a delay time of mean ± s.d. 25.3 ± 0.8 s. Plasma lactate kinetics based on measurement of lactate in each fraction showed an exponential increase during the first 13 min of exercise (10.5 min of SET and 2.5 min recovery). The peak plasma lactate concentration was observed between 2.5 and 5.5 min after the end of SET. CBWM permits the kinetics of lactate and other blood‐borne variables to be studied over time. This method could be a valuable aid for use in studying equine exercise physiology.
Measurement of serum amyloid A in the neonatal foal using a latex agglutination immunoturbidimetric assay: determination of the normal range, variation with age and response to disease
Authors: STONEHAM S. J. , PALMER L. , CASH R. , ROSSDALE P. D. 
Published: April 2007

SummaryThis paperdescribes the use of a latex agglutination assay to measure serum amyloid A (SAA) in the neonatal foal. The normal range and response to clinical disease was determined. This retrospective study evaluated SAA concentrations over the first 3 dayspostpartumof 226 Thoroughbred foals judged to be clinically healthy. The normal range for each day was determined; levels were found to be significantly highest on Day 2 (Day 1 vs. Day 2 P<0.0001). The 95th percentile for Days 1–3 was 27.1 mg/l.Clinical records of 133 foals, presented as first or second opinion cases, were evaluated. Foals were divided into 4 groups; septicaemia (S), focal infection (FI), failure of passive transfer (FPT) and noninfectious disease (NI). There was a statistically significant difference (P<0.0001) between SAA concentrations of control foals compared toGroups SandFI.There was no statistically significant difference between controls andGroups FPTandNI.WhenGroup NIwas compared toGroups SandFI, there was a statistically significant difference (P<0.0001).The authors suggest that SAA determined by this latex agglutination assay might be a helpful aid in the diagnosis of septicaemia and focal infection in neonatal foals; levels >100 mg/l are highly suggestive of infection in young foals.
Effects of an external nasal strip and frusemide on pulmonary haemorrhage in Thoroughbreds following high‐intensity exercise
Authors: GEOR R. J. , OMMUNDSON L. , FENTON G. , PAGAN J. D. 
Published: April 2007

SummaryThe purpose of this study was to examine the effects of an external nasal strip (NS), frusemide (FR) and a combination of the 2 treatments (NS + FR) on exercise‐induced pulmonary haemorrhage (EIPH) in Thoroughbred horses. It was hypothesised that both the NS and FR would attenuate EIPH as assessed by red blood cell count in bronchoalveolar lavage fluid. In random order, 8 horses completed each of 4 sprint exercise tests on a treadmill: 1) NS; 2) FR (0.5 mg/kg bwt i.v., 4 h pre‐exercise); 3) NS + FR; and 4) control (C; no treatment). After a 5 min warm‐up (4.5 m/s), horses completed 2 min running at 120% maximum oxygen consumption (Vo2max) with the treadmill set at 3° incline. Mean ± s.d. running speed was 14.2 ± 0.2 m/s. In the FR and NS + FR trials, horses carried weight equal to that lost as a result of frusemide administration. During exercise at 120%V̇O2max, oxygen consumption (Vo2) and carbon dioxide production (Vco2) were measured at 15 s intervals. Plasma lactate concentration was measured in samples collected before exercise, at the end of the sprint and after 5 min cooldown at the trot. Thirty minutes after the run, bronchoalveolar lavage (BAL) was performed and the red cell count in the fluid quantified. Vo2and Vco2were significantly lower in NS and NS + FR trials than in the C and FR trials at the end of the sprint exercise protocol. However, plasma lactate concentrations did not differamong treatments. Compared with the C trial (61.1 ± 30.5 × 106red blood cells/ml BAL fluid), pulmonary haemorrhage was significantly (P<0.05) decreased in both the NS (15.9 ± 4.0 × 106RBC/ml) and FR (12.2 ± 5.8 × 106RBC/ml) trials. EIPH in the NS + FR trial (7.9 ± 1.0 × 106RBC/ml) was further diminished (P<0.05) compared to the NS trial, but not different from the FR trial. We conclude that both the external nasal strip and frusemide attenuate pulmonary haemorrhage in Thoroughbred horses during high‐speed sprint exercise. The external nasal strip appears to lowerthe metabolic cost of supramaximal exertion in horses. Given the purported ergogenic effects of frusemide, the external nasal strip is a valuable alternative for the attenuation of EIPH.
Effect of partial replacement of oats with sugar beet pulp and maize oil on nutrient utilisation in horses
Authors: LINDBERG J. E. , KARLSSON C. PALMGREN 
Published: April 2007

SummaryThe objective of the present work was to assess the influence of partial replacement of oats with dried unmolassed sugar beet pulp (SBP) and/or maize oil on nutrient utilisation in horses fed a traditional hay and concentrate diet.The total tract digestibility of nutrients, urinary excretion and plasma parameters were studied in a 4 × 4 Latin‐square design experiment with purebred Arabian geldings. Horses fed the SBP diets responded with a reduced (P<0.05) apparent digestibility of crude protein and feeding of maize oil resulted in an increased (P<0.05) apparent digestibility of crude fat. The apparent energy digestibility was unaffected by the replacement of oats with SBP, but increased (P<0.05) when maize oil replaced part of the oats. The urinary excretion of nitrogen increased (P<0.05) when maize oil replaced oats and the excretion of energy was higher (P<0.05) on the diets where oats were replaced by maize oil and SBP.There was a significant (P<0.05) effect across treatments of postprandial blood sampling time on plasma glucose and insulin concentrations. Also, plasma concentrations of glucose and insulin tended to be higher on the oats than on the SBP diets.In conclusion, the limited effects on the digestibility of nutrients and energy suggest that it should be possible to partially replace oats with maize oil and/or SBP in diets for horses without any impairing effects on the overall nutrient utilisation. However, the dietary‐induced changes in the urinary excretion of energy and on plasma glucose and insulin levels, indicate a possible influence of dietary carbohydrate composition on nutrient utilisation at the organ level, which requires further study.
Effect of GnRH immunisation on hormonal levels, sexual behaviour, semen quality and testicular morphology in mature stallions
Authors: MALMGREN L. , ANDRESEN Ø. , DALIN A.‐M. 
Published: April 2007

SummaryThe aim of this study was to investigate the effect of gonadotrophin‐releasing hormone (GnRH) immunisation on mature stallions that had been used for breeding. Four Standardbred stallions were used in the study: 3 experimental animals and 1 control animal. Semen was collected regularly, i.e. twice/week, during the 4 months prior to the experimental period. The stallions were immunised against GnRH with a GnRH‐BSA conjugate. Equimune was used as the adjuvant. The stallions were immunised on 5 occasions, 4 at 2 week intervals, and the fifth 4 weeks after the fourth. Blood samples were taken once a week for analysis of GnRH antibody titre and every third week for testosterone and oestrone sulphate analyses. Semen was collected once a week, and libido and sexual behaviour were observed. Ejaculate volume, sperm concentration, total number of sperm in the ejaculate, sperm motility and sperm morphology were evaluated. Testicular size was measured once a week. At the end of the study, the stallions were castrated, and a histological examination of the testes performed.All immunised stallions produced antibodies against GnRH, and plasma testosterone concentration decreased. However, the effect of immunisation varied between stallions. In 2 of the stallions, high levels of antibodies were found, while in the third, the level was moderate. Four weeks after the first immunisation, a decrease in libido was observed. Two months after the first immunisation, marked changes in semen quality were observed in the 2 stallions with high antibody titres. Fourteen weeks after the first immunisation, the total number of sperm/ejaculate had decreased from >8.6×109 to<2.7×109, sperm motility from >59 to<10% and the frequency of morphological normal spermatozoa had decreased from >60 to<14%. The dominating abnormalities were abnormal head shapes, proximal cytoplasmic droplets and detached heads. In the third stallion, only slight changes in semen quality were found. No changes were observed in the control stallion.Decreases in testicular size were noted in all of the experimental stallions. Pronounced histological alterations in the testes were observed in 2 of the stallions.It is concluded that the vaccine was effective in stimulating production of GnRH antibodies and in suppressing testicular function and androgen secretion. However, there was an individual variation in the responses among the stallions and, further, libido was not totally suppressed.
Contact areas and pressure distribution on the proximal articular surface of the proximal phalanx under sagittal plane loading
Authors: BRAMA P. A. J. , KARSSENBERG D. , BARNEVELD A. , van WEEREN P. R. 
Published: April 2007

SummaryThe objective of this study was to map topographically contact areas and pressure distributions on the proximal articular surface (PAS) of the proximal phalanx (PI) under various clinically relevant loading conditions. Left and right forelimbs of 13 mature horses were transected halfway down the radius and loaded in a position mimicking the weightbearing attitude close to the midstance phase. Five loads were used which corresponded with loads that can be expected in different gaits or during athletic performance (stance: 1800 N, walk: 3600 N, trot: 5400 N, gallop: 10,500 N and jumping: 12,000 N). Contact areas and pressure distributions at the PAS of PI were determined using a methylene blue dye staining technique and 2 pressure sensitive films (low pressure: range 2.5–10 MPa and medium pressure: range 10–50 MPa).The contact area of PI was positively correlated (r = 0.86; P<0.01) with the applied load. The contact area increased from 63% at 1800 N to 95% at 12,000 N and gradually shifted to include more of the edges of the articular surface, but especially the dorsal articular margin of PI. Pressure distribution patterns were similar under the different loading conditions. Pressure was less at the palmar margin and in the central depression and highest at the dorsal articular margin. With increasing load, the highest peak pressures were measured at sites of the dorsal articular margin that are not loaded in the standing or walking horse. The results of this study suggest that the frequent occurrence of osteochondral lesions at the dorsal articular margin of PI is caused by the combination of the intermittent character and the high absolute values of loads at this site as they occur during athletic performance.