bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiovascular effects of surgical castration during anaesthesia maintained with halothane or infusion of detomidine, ketamine and guaifenesin in ponies
Authors: TAYLOR POLLY M. , KIRBY J. J. , SHRIMPTON D. J. , JOHNSON C. B. 
Published: April 2010

SummarySixteen colts were premedicated with acepromazine and anaesthesia was induced with detomidine and ketamine. Ponies were randomly allocated to receive halothane (HAL) or infusion of detomidine, ketamine and guaiphenesin (DKG) to maintain anaesthesia. Heart and respiratory rate, ECG, mean arterial blood pressure (MABP), cardiac index (CI), blood gases and plasma Cortisol, ketamine and guaiphenesin were measured. Surgical castration took place between 45 and 75 min and anaesthesia lasted 90 min. MABP with DKG was significantly higher than with HAL, and, with HAL, MABP increased from pre‐surgery (64 ± 6 mmHg) to mid‐surgery (80 ± 5 mmHg) but did not change with DKG. At 30 min, CI was similar in both groups (57 ± 7 ml/kg bwt/min); it decreased during surgery with HAL and remained low, but it increased slightly with DKG, and was higher than with HAL at 60 and 90 min. Plasma Cortisol decreased in both groups until 40 min then increased with HAL only during surgery. Ketamine concentration reached a plateau (1.3‐1.8 μg/ml) between 20 and 90 min and guaiphenesin concentration between 60 and 90 min (99–101 μg/ml). Recovery was generally smooth in both groups. This study demonstrated that during HAL the increase in blood pressure associated with surgical stimulus is accompanied by decreased CI; this did not occur during DKG which is likely to lead to better tissue perfusion than HAL. The adrenocortical activity seen during HAL was absent during DKG which may result from pituitary depression, analgesic effects of total intravenous anaesthesia (TIVA) or better perfusion.
Glomerular filtration rate, effective renal plasma flow, blood pressure and pulse rate in the equine neonate during the first 10 dayspost partum
Authors: HOLDSTOCK NICOLA B. , OUSEY JENNIFER C. , ROSSDALE P. D. 
Published: April 2010

SummaryThe aim of this study was to determine glomerular filtration rate (GFR), effective renal plasma flow (RPF) and filtration fraction (FF) values in Pony foals during the first 10 dayspost partumin order to assess any age‐related changes and the reliability of the single injection inulin/p‐aminohippurate (PAH) method. Arterial blood pressure and pulse rate were determined in Pony and Thoroughbred (TB) foals during the first 10 dayspost partumto establish age‐related changes, differences between breeds and possible interrelationships with GFR and RPF.Inulin and PAH were injected intravenously (i.v.) in healthy Pony foals (n = 6) on Days 1, 2, 4, 7 and 10post partum.Blood samples were collected via the contralateral jugular catheter over a 4 h period. Plasma clearances of inulin and PAH showed that GFR and RPF, respectively, remained relatively constant throughout the post natal period, and were similar to values reported for mature horses. The GFR measurements obtained using the inulin method gave clearance values that were significantly higher (P<0.01) than those of creatinine clearance performed in a separate group of Pony foals (n = 7).Blood pressure and pulse rates were measured using an electronic sphygmomanometer in TB (n = 6) and Pony foals (n = 7) on Days 1,2,3,4,7 and 10post partum.There were no significant differences in these measurements between the breeds, and both cardiovascular parameters increased during the first 3 dayspost partum.Values remained unchanged for the rest of the study period. Although measurements of GFR, RPF, blood pressure and pulse rates were not determined in the same animals, blood pressure and pulse rates did not appear to correlate with either GFR or RPF in the Pony foals during the post natal period.
Inhibin secretion in the stallion
Authors: NAGATA S. , MIYAKE Y‐I. , NAMBO Y. , NAGAMINE N. , WATANABE G. , TSUNODA N. , TANIYAMA H. , HONDO E. , YAMADA J. , TAYA K. 
Published: April 2010

SummaryTo examine the physiological role of inhibin in the stallion, a heterologous radioimmunoassay (RIA) based on a bovine RIA was validated and used to measure immunoreactive (ir)‐inhibin concentrations in plasma and testicular homogenates. The bioactivity of equine testicular inhibin was also examined using an assay for suppression of FSH secretion from rat anterior pituitary cells. In addition, to identify the cell responsible for secreting testicular inhibin, the localisation of inhibin in the testis was investigated by an immunohistochemical method using a polyclonal antibody against (Tyr30)‐porcine inhibin α(1–30) NH2. In the RIA, parallel dose response curves were obtained for the bovine inhibin standard and serial dilutions of stallion plasma and equine testicular homogenates. Parallel FSH inhibition curves were also observed for the bovine inhibin standard and serial dilutions of equine testicular homogenates in the bioassay. The inhibition of FSH secretion from rat pituitary cells by equine testicular homogenates was neutralised by an antiserum against bovine inhibin in vitro. Plasma concentrations of ir‐inhibin, testosterone and oestradiol‐17ß in stallions decreased abruptly after bilateral gonadectomy and FSH and LH concentrations in the plasma subsequently increased. Therefore, circulating inhibin in the stallion appeared to be largely of testicular origin. The histochemical results showed for the first time that strong immunopositive staining for inhibin occurred in the Leydig cells of the testes. Sertoli cells were also stained by the inhibin antibody but the reaction was weaker than that in Leydig cells. These results indicate clearly that both Leydig and Sertoli cells are potential sources of testicular inhibin in the stallion. A clear increase in plasma ir‐inhibin concentrations was observed during the natural breeding season. Similar seasonal changes in the plasma concentrations of testicular steroid hormones and pituitary gonadotrophins occurred throughout the year.In conclusion, the testes appear to be the main source of inhibin, and testicular inhibin is secreted by Leydig and Sertoli cells in stallions. The positive correlations between plasma ir‐inhibin and testicular activity during both the breeding and nonbreeding seasons indicate that plasma irinhibin is a useful indicator of reproductive activity in the stallion.
Pulmonary vascular pressures of strenuously exercising Thoroughbred horses after administration of phenylbutazone and frusemide
Authors: MANOHAR M. , GOETZ T. E. , SULLIVAN EILEEN , GRIFFIN R. 
Published: April 2010

SummaryThe present study was carried out to examine the effects of phenylbutazone treatment on the pulmonary haemodynamic effects of frusemide in strenuously exercising horses. Using catheter mounted manometers, whosein vivosignals were referenced at the point of the shoulder, heart rate, right atrial, right ventricular and pulmonary vascular pressures were measured in 3 different sets of experiments. Seven Thoroughbreds were subjected to 1) control (no medications), 2) frusemide control and 3) phenylbutazone + frusemide. The experiments were carried out in random order and were separated by 7 days. Measurements were made at rest and during incremental exercise performed on a treadmill set at 3.5% uphill grade. In the frusemide control experiment, horses received frusemide 250 mg i.v., 4 h pre‐exercise. In the phenylbutazone + frusemide experiment, horses received 4 i.v. injections of phenylbutazone (4.4 mg/kg bwt) at 12 h intervals. Twenty‐four hours after the last phenylbutazone injection, horses received frusemide 250 mg i.v. and exercise was performed 4 h later. This latter regimen mimics prevailing veterinary practice at Illinois racetracks. The highest work intensity (14.2 m/s, 3.5% uphill grade) elicited maximal heart rate of horses. Significant right atrial, as well as pulmonary arterial, capillary and venous hypertension occurred with exertion in all 3 experiments. However, in the frusemide‐control and the phenylbutazone + frusemide studies, the exercise induced rise in mean right atrial and pulmonary vascular pressures was significantly (P<0.05) attenuated in comparison with that in the control experiments. Statistically significant differences were not found between the frusemide control study and the phenylbutazone + frusemide study either at rest or during any level of exertion. Therefore, it was concluded that the phenylbutazone treatment in our study did not mitigate the pulmonary haemodynamic effects of frusemide in strenuously exercising Thoroughbred horses.
Impact of mixed strongyle infections in foals after one month on pasture
Authors: THAMSBORG S. M. , LEIFSSON P. S. , GRØNDAHL C. , LARSEN M. , NANSEN P. 
Published: April 2010

SummaryTwelve Standardbred foals (age 3–6 months), with little previous exposure to parasites, were allocated to 2 groups and put onto pasture with low (Group L) or high (Group H) levels of larval contamination of large strongyles and cyathostomes. After 4 weeks grazing in September, the foals were housed indoors until necropsy 15 weeks later. Foals in Group H became clinically more affected than those of Group L in that they showed loss of vigour, weight gain depression, intermittent soft faeces and inappetence. One foal of Group H had persistent diarrhoea and was subjected to euthanasia 12 weeks after housing. Signs of colic were not observed. Faecal egg counts were significantly higher in Group H than in Group L (P<0.05). At necropsy, the mean number of S. vulgaris and cyathostomes was 20 and 18,000, respectively, in Group L, and 167 and 25,000 in Group H. Routine blood chemistry did not specifically reveal presence of S. vulgaris in pre‐patency. A transient neutrophilia and eosinophilia, most prominent in Group H, was seen 2–8 weeks after start of exposure and anaemia was observed later in Group H. Serum albumin and albumin/globulin ratio were reduced, particularly in Group H, and a marked hyperbetaglobulinaemia was observed at 16–20 weeks in Group H. In conclusion, heavy infections with strongyles including S. vulgaris may become established in weaned foals after a brief period on pasture. Infections may be expressed clinically as debilitation, inappetence and intermittent diarrhoea without colic, and the need for control is imperative.
Quantitative assessment of motor neuron loss in equine motor neuron disease (EMND)
Authors: POLACK EVELYNE WEBER , KING J. M. , CUMMINGS J. F. , DE LAHUNTA A. , DIVERS T. J. , MOHAMMED H. O. 
Published: April 2010

SummaryThe mean number of motor neurons was assessed in the C7 spinal cord segment of 5 EMND and 5 control horses. Mean number per section in EMND horses was reduced significantly (P<0.001). The mean neuronal loss was estimated at 31%. Each of the 5 affected horses had a mean neuronal count below the 95% confidence interval for control horses. The statistically significant difference between the 2 groups was consistent in the cranial, middle and caudal thirds of the C7 segment (P<0.001). The results of regression analysis indicated an association between neuronal reduction in EMND horses and the duration of the disease when adjusted for age (P<0.001). This is the first quantitation of the neurodegenerative loss in EMND and it provides a clearer explanation for residual deficits in horses that survive EMND.
Bone scintigraphy in the diagnosis of sacroiliac injury in twelve horses
Authors: TUCKER R. L. , SCHNEIDER R. K. , SONDHOF A. H. , RAGLE C. A. , TYLER J. W. 
Published: April 2010

SummaryNuclear bone scintigraphy was used to diagnose sacroiliac injury in 12 horses presented for nonspecific rear limb lameness. The most common history was decreased performance and/or a mild chronic rear limb lameness which could not be localised by routine lameness examination. The scintigraphic patterns of the 12 affected horses were compared to 5 normal horses and 10 horses with lameness not related to the pelvic region. Subjective and quantitative evaluation of the bone scans clearly separated the 12 affected horses from the S normal horses and the 10 horses with lameness from causes other than the sacroiliac joint disease. The 12 affected horses had a scintigraphic pattern of moderate to marked increased uptake of the radiopharmaceutical within the sacroiliac joint region on the side of lameness. In contrast, the 5 normal horses and 10 horses scanned for other causes of lameness, had a symmetric, or only slightly asymmetric pattern of radioisotope uptake. Although nonspecific for the type of injury, nuclear bone scintigraphy is considered sensitive for the detection of sacroiliac injuries in horses.
Clinical assessment of gas exchange in mature horses
Authors: DAVIS M. S. , MURRAY M. J. , DONALDSON LYDIA L. 
Published: April 2010

SummaryThere are limited methods of assessing pulmonary function in horses at rest. We developed clinical techniques to measure gas exchange efficiency in horses and evaluated 3 groups of horses that were 1) asymptomatic based on auscultation with rebreathing, transtracheal aspirate cytology, and thoracic radiographs (n = 6), 2) asymptomatic at rest but symptomatic with rebreathing (n = 11) and 3) symptomatic at rest (n = 9). Blood samples were obtained from the transverse facial artery and jugular vein. Maximal end‐tidal CO2tension (PETCO2) was measured by an infrared capnograph through a facemask. Alveolar O2tension, dead space fraction (VD/VT), and physiological shunt fraction (QS/QT) were calculated using standard formulae. Arterial O2tension inGroup 1horses (mean ± s.d. 103 ± 3 mmHg) was significantly higher than inGroup 2orGroup 3horses. QS/QTinGroup 1horses (0.37 ± 0.98%) was significantly lower than inGroup 2andGroup 3horses. Mean ± s.d.VD/VTinGroup 1horses (‐18.2 ± 3.1) was significantly lower thanGroup 3horses but notGroup 2horses.
Prevalence and characteristics of foal rejection in Arabian mares
Authors: JUARBE‐DÍAZ SORAYA V. , HOUPT KATHERINE A. , KUSUNOSE R. 
Published: April 2010

SummarySeparate surveys of Thoroughbred, Paint, and Arabian mare owners revealed a higher than expected rate of foal rejection in Arabian mares. A behavioural history form was submitted by owners of foal rejecting and nonrejecting Arabian mares, and maternal behaviour and management practices compared. Four generation pedigrees of rejecting and nonrejecting Arabian mares were also examined. Foal rejecting mares were more likely to avoid, threaten, squeal at, chase, bite, and kick their foalspost partumthan nonrejecting mares. Nonrejecting mares were more likely to lick, nicker and defend their foalspost partumthan rejecting mares. No statistically significant relationship was found between foal rejection and the type of breeding method (natural vs. artificial insemination), the presence of people at birth, the presence of nearby horses at birth, or assistance of the first nursing bout. The presence at least once of 1 of 2 related sires was statistically higher in the pedigrees of rejecting vs. nonrejecting mares. Inherited and learned or environmental factors are likely to affect the expression of foal rejection behaviour.
Cytology of 100 samples of abdominal fluid from 100 horses with abdominal disease
Authors: GARMA‐AVIÑA A. 
Published: April 2010

SummaryA total of 100 samples of abdominal fluid (AF) from 100 horses with abdominal disease were evaluated by cytology. Cytology results were subsequently correlated with the final outcome of the disease. The horses were classified into 4 groups: Group I, horses that were treated with conventional (nonsurgical) therapy and recovered; Group II, horses that had surgery and survived; Group III, horses that had surgery but died; and Group IV, horses that were subjected to euthanasia prior to surgery. Statistical analysis showed that both nucleated cell count and total neutrophils were significantly higher in Group III than in Group I; and that the total mesothelial cells were significantly higher in Group III than in Groups I and II. No significant differences were found for erythrocyte counts and fluid total protein levels among the 4 groups. The findings suggest that classifying AF as transudate, modified transudate and exudate, as well as grading of inflammation as mild, moderate and severe on the basis of nucleated cell count (NCC) and fluid total protein (AFTP) can be greatly misleading. Differential identification of the nucleated cells was found to be far more reliable than the NCC alone, with or without the AFTP, and rendered valuable information, which overuled many times a diagnosis of transudate or modified transudate. Bands, metamyelocytes, toxic changes, plasma cells, and neutrophils penetrating rafts or fronds of mesothelial cells, supported a diagnosis of inflammation, even when the NCC, and the AFTP (interpreted according to currently accepted values) suggested otherwise. Several morphological features were found, including some cell types for which little or no mention was found at all in 22 major studies of this fluid in horses. Among these were ‘reddish neutrophils’, large granular lymphocytes (LGL), plasma cells, Mott cells, blasts, and a unique hitherto undescribed granular mesothelial cell.
Angular kinematic patterns of limbs in elite and riding horses at trot
Authors: MORALES J. L. , MANCHADO M. , VIVO J. , GALISTEO A. M. , AGÜERA E. , MIRÓ F. 
Published: April 2010

SummaryNormal speed videography was used to determine the angular parameters of 28 Spanish Thoroughbreds at trot. Horses were divided into 3 groups:Group UT, comprising 9 animals (provided by the VII National Stud, Córdoba, Spain) which had undergone no specific training programme and which were hand led at the trot;Group T, formed by 19 horses considered to be highly bred and trained, and which were also hand led; andGroup RT, comprising the same horses as the latter group but this time trotted by a rider. Each animal was filmed 6 times from the right‐hand side, using a Hi8 (25 Hz) video camera. Angular parameters for fore‐ and hindlimb joints were measured in each stride from computer‐grabbed frames and entered into a spreadsheet for calculation; parameters included maximum and minimum angles, range of motion, and angles at landing, lift off and maximum hoof height; the times at which maximum angle, minimum angle, lift off and maximum hoof height occurred were calculated as percentages of total stride duration. Stride velocity (mean [s.d.]) was 4.01 (0.62), 3.60 (0.34) and 3.07 (0.36) m/s forGroups UT, TandRT, respectively. Data were then compared betweenGroups UT‐TandGroups T‐RT.Compared withGroup UT, horses fromGroup Tfeatured a shorter stance percentage (P<0.001) in both fore‐ and hindlimbs. The range of motion in forelimbs was smaller (P<0.05), due to lower retraction (P<0.001); moreover, maximum retraction appeared earlier (P<0.05). Greater scapular inclination was in evidence (P<0.05) and the shoulder joint extended further (P<0.05). Fore‐ and hind fetlock joints revealed a relatively shorter hyperextension period during the stance phase (P<0.01).Compared withGroup T, horses fromGroup RThad a longer stance percentage, with belated maximum retraction of the fore‐ and hindlimbs. The range of movement in scapular inclination was greater (P<0.05), due to a smaller minimum angle (P<0.01), and the shoulder joint flexed more (P<0.05). The elbow joint extended more and for longer during the stance phase. Initial extension of the hip joint (P<0.05) and tarsus (P<0.001) lasted longer. The carpal and fore and hind fetlock joints recorded relatively longer hyperextension times, in addition to greater hyperextension during the stance phase.The results from the present study suggest that rider‐effect must be taken in consideration when well gaited horses are selected for dressage purposes.
Physeal growth retardation leads to correction of intracarpal angular deviations as well as physeal valgus deformity
Authors: BRAUER T. S. , BOOTH T. S. , RIEDESEL E. 
Published: April 2010

SummaryRetrospective analysis of the radiographs of horses with carpal valgus, presented to the Iowa State University Veterinary Teaching Hospital from 1987–1996, were used to compare 2 methods of geometric analysis for finding the total angle of deviation. The pivot point angle method and the individual joint angle method were found to be comparable for determining the total angle of deviation. The individual joint angle method was used to analyse individual carpal joint angles and physis angle in joints with carpal valgus, as well as the changes that occurred in response to surgical correction. Multiple joint involvement was common with carpal valgus; and surgical manipulation caused a change in angle at all joints. Use of the individual joint angle method for evaluating carpal valgus may aid the surgeon in making a more accurate prognosis.
Comparison of bacteriology and cytology of tracheal fluid samples collected by percutaneous transtracheal aspiration or via an endoscope using a plugged, guarded catheter
Authors: CHRISTLEY R. M. , HODGSON D. R. , ROSE R. J. , REID S. W. J. , HODGSON J. L. 
Published: April 2010

SummaryCytological and bacteriological results from tracheal fluid samples obtained endoscopically using a telescoping, plugged catheter (TPC) were compared with results from samples collected by percutaneous transtracheal aspiration (PTA). The TPC technique and PTA were performed in random order on 9 healthy Standardbred geldings. Three weeks later the procedures were performed on the same horses in the reverse order. The presence of oropharyngeal contamination was determined by quantitative bacteriology and quantification of squamous epithelial cells (SEC)/ml sample. The relative numbers of macrophages, haemosiderophages, giant cells, neutrophils, lymphocytes and eosinophils did not differ between techniques. The number of SEC/ml was greater in samples with more colony forming units/ml indicating that quantification of SEC provides evidence of the probable degree of oropharyngeal contamination. Fifteen out of the 18 TPC samples were free of contamination, indicating that the TPC can provide adequate samples for bacteriology. The results also indicate that tracheoscopy sometimes results in oropharyngeal contamination of the trachea, but that this does not affect the results of the TPC sample.