bluuebunny/crossref_metadata_2025_split huggingface dataset:
The radiographic development of the distal and proximal double contours of the equine navicular bone on dorsoproximal‐palmarodistal oblique (upright pedal) radiographs, from age 1 to 11 months
Authors: DIK K. J. , van den BELT A. J. M. , ENZERINK E. , van WEEREN P. R. 
Published: April 2007

SummaryThe aim of this study was to monitor the postnatal radiographic development of the proximal and distal double contours and the modelling of the shape of the proximal articular border. In mature horses, the proximal and distal contours of the navicular bone on dorsopalmar dorsoproximal‐palmarodistal oblique (upright pedal) radiographs are commonly visualised as 2 lines, one being the articular border and the second representing the border of the cortex facing the deep digital flexor tendon (flexor border). The shape of the proximal articular border may be concave, undulating, straight or convex in the mature animal. These shapes have been found to be hereditary and to constitute a predisposing factor in the pathogenesis of navicular disease. This predisposing role may result from a shape dependent distribution of the biomechanical forces exerted on this region. There is no agreement in the literature with respect to the moment when the navicular bone takes its mature radiographic appearance.Upright pedal radiographs of the left front foot of 19 Dutch Warmblood foals were made at age 1 month and subsequently at intervals of 4 weeks, until the age of 11 months. The distal double contour developed soon after birth and the radiographic visibility of the articular border improved from ill‐defined at 1 or 2 months to clear manifestation at 3 or 4 months. The proximal double contour developed later. The articular border became usually visible at age 3 or 4 months and was clearly visible from age 9 months. The mature shape of the proximal articular border usually became recognisable from age 7 months and was always obvious between 9 and 11 months. This development was associated with a gradual modelling of the lateral and medial extremities of the navicular bone.It was concluded that the navicular bone adopts its mature radiological appearance during the first yearpostpartum.Considering this early manifestation of the mature shape of the proximal articular border and its previously demonstrated inheritance, a force‐dependent development of this shape, as predicted by the trajectional theory/Wolffs law, is improbable. The predisposing role of this shape in the pathogenesis of navicular disease may therefore be explained by a shape‐dependent distribution of the biomechanical forces exerted on the navicular bone. Considering the potential application of these findings, from age 1 year shape determination enables identification of the individual and breed susceptibility for the development of navicular disease.
Acute thrombosis of limb arteries in horses with sepsis: five cases (1988–1998)
Authors: BRIANCEAU P. , DIVERS T. J. 
Published: April 2007

SummaryA hypercoagulable condition and poor perfusion to distal extremities might occur during equine endotoxaemic or septic shock, which could cause thrombosis of limb arteries. In our review, thrombosis occurred in neonatal foals in association with Gram‐negative bacteraemia. In 3 olderfoals and adults, thrombosis was associated with inflammatory bowel disease, diarrhoea and toxaemia. All patients had been treated with broad‐spectrum antibiotics, nonsteroidal anti‐inflammatory drugs and i.v. crystalloid solutions. Two horses received i.v. hyperimmune plasma. A generalised coagulopathy was not suspected prior to clinical signs of distal limb necrosis, although thrombocytopenia occurred in 4 of the 5 cases at the time of, or shortly before, thrombosis. Thrombocytopenia, possibly due to platelets adherence to exposed subendothelial collagen, which induces contact activation of the intrinsic coagulation pathway, has been described in endotoxaemic horses and foals with gastrointestinal infectious or inflammatory diseases and disseminated intravascular coagulation.Activation of procoagulants by endotoxins, decreased blood flow to the limbs and endothelial damage, may have been responsible for a hypercoagulable condition leading to thrombosis in these 5 cases. The 3 enterocolitis patients may have had increased risk of thrombosis because of loss of antithrombin III, haemoconcentration and acidosis.
Standing laparoscopic herniorrhaphy in stallions using cylindrical polypropylene mesh prosthesis
Authors: MARIËN T. 
Published: April 2007

SummaryStanding laparoscopic herniorrhaphy was performed in 9 stallions. Appropriate analgesia was achieved by sedation with detomidine and local flank infiltration with mepivacaine. Three portal sites at the paralumbar fossa were used to perform the herniorrhaphy by means of triangulation. A cylindrical polypropylene mesh was inserted and fixated in the inguinal canal. Subsequent adhesion formation resulted in an obliterated inguinal canal within 2 weeks. This minimal invasive technique allowed us to perform a testis sparing herniorrhaphy in the standing horse.
The hindlimb in walking horses: 1. Kinematics and ground reaction forces
Authors: HODSON E. , CLAYTON H. M. , LANOVAZ J. L. 
Published: April 2007

SummaryThe objective was to study associations between kinematics and ground reaction forces in the hindlimb of walking horses. Video (60 Hz) and force (2000 Hz) data were gathered for 8 strides from each of 5 sound horses during the walk. Sagittal plane kinematics were measured concurrently with the vertical and longitudinal ground reaction forces. The hindlimb showed rapid loading and braking in the initial 10% stride. The stifle, tarsal and coffin joints flexed and the fetlock joint extended during this period of rapid loading. The vertical ground reaction force showed 2 peaks separated by a dip; this pattern was similar to the fetlock joint angle‐time graph. Peaks in the longitudinal ground reaction force did not appear to correspond with kinematic events. Total braking impulse was equal to total propulsive impulse over the entire stride. Flexion and extension of the hip were responsible for protraction and retraction of the entire limb. Maximal protraction occurred shortly before the end of swing and maximal retraction occurred during breakover. During the middle part of stance the tarsal joint extended slowly, while the stifle began to flex when the limb was retracted beyond the midstance position at 28% stride. Flexion cycles of the stifle and tarsal joints were well coordinated during the swing phase to raise the distal limb as it was protracted. The results demonstrate a relationship between limb kinematics and vertical limb loading in the hindlimbs of sound horses. Future studies will elucidate the alterations in response to lameness.
Risk factors associated with hindlimb lameness and degenerative joint disease in the distal tarsus of Icelandic horses
Authors: AXELSSON M. , BJÖRNSDOTTIR S. , EKSELL P. , HÄGGSTRÖM J. , SIGURDSSON H. , CARLSTEN J. 
Published: April 2007

SummaryThe aim of this study was to evaluate potential risk factors associated with hindlimb lameness and radiographic signs of degenerative joint disease (DJD) in the distal tarsus in Icelandic horses. The material consisted of riding horses (n = 420) age 6–12 years sired by 17 selected sires representing all major breeding lines, and of riding horses (n = 194) in the same age range sired by other sires. The examination protocol included the following: interview with owners/trainers, assessment of conformation, motion evaluation and radiographic examination. At the interview, data related to factors outside the horse (environmental variables) and data associated directly with the horse (intrinsic variables) were obtained. Data analysis was performed in 2 steps: screening using bivariate analysis, followed by testing with a multivariate logistic regression model. In the multivariate analysis, the factors of sire, age when broken to saddle and stud show participation were strongly associated with the prevalence of lameness. Height at the croup and ability to perform different gaits were also associated with the prevalence of lameness, but to a lesser degree. The risk factors of age, tarsal angle and birthplace were significantly associated with radiographic signs of DJD in the distal tarsus. Neither the variation in applied training intensity, the use of a professional oramateurtrainernorthe temperament or front limb action of the individual horse was significantly associated with the prevalence of hindlimb lameness and/or radiographic signs of DJD in the distal tarsus in the Icelandic horse.
Heparinised blood ionised calcium concentrations in horses with colic or diarrhoea compared to normal subjects
Authors: van der KOLK J. H. , NACHREINER R. F. , REFSAL K. R. , BROUILLET D. , WENSING Th. 
Published: April 2007

SummaryOur objectives were to 1) establish ionised calcium (ICa), C‐terminal PTH and biologically active PTH (intact molecule) concentrations in blood from normal horses, 2) examine the stability of ionised calcium and acid‐base values in stored equine heparinised blood and serum and 3) check the applicability of the formulas based on these parameters in certain disease states.Mean ± s.d. % ionised calcium in heparinised blood of normal Warmbloods was 51 ± 2.7 (n = 20) of total calcium, range 1.45–1.75 mmol/l (n = 15) at Michigan State University and 1.43–1.69 mmol/l (n = 20) at Utrecht University. Mean ± s.d. EDTA plasma concentration for intact PTH in normal horses measured 0.6 ± 0.3 pmol/l (n = 11). Both mean serum and the heparinised blood ionised calcium concentrations changed (not significantly) after 102 h storage at room temperature. Six cycles of freezing and thawing did not affect serum ionised calcium concentration significantly. Ionised calcium concentration and pH in heparinised blood of 20 normal Warmbloods were used to calculate the regression equation for the prediction of the adjusted ionised calcium concentration to a pH of 7.4. The linear regression equation found was: adjusted plasma ICa at pH 7.4 mmol/l =−6.4570 + 0.8739 × (measured pH) + 0.9944 × (measured ICa mmol/l). By means of this formula, mean adjusted ionised calcium concentration in heparinised blood calculated was 100% of the actual value given by the analyser in the normal horses. When using this formula in horses with colic or diarrhoea, mean adjusted ionised calcium concentration was underestimated by 0.2 and 0.3%, respectively. Furthermore, to adjust the measured ionised calcium concentration in heparinised blood to a pH of 7.4 in healthy as well as in 2 groups of diseased horses 2 formulas with a good prediction are now available.
Treatments to promote colonic hydration: enteral fluid therapy versus intravenous fluid therapy and magnesium sulphate
Authors: LOPES M. A. F. , WALKER B. L. , II N. A. WHITE , WARD D. L. 
Published: April 2007

SummaryAlthough large intestine impactions are commonly treated with i.v. fluids combined with the osmotic laxative MgSO4, enteral fluids are less expensive and also appear to be efficacious for impactions. Therefore, this study was conducted to compare the systemic and gastrointestinal effects of enteral fluids with the changes produced by i.v. fluids combined with MgSO4. Four horses with a fistula in the right dorsal colon alternately received both treatments in 2 periods one week apart. Sixty litres of fluids were administered continuously (10 l/h) through a venous catheter or a nasogastric tube. Magnesium sulphate (1 g/kg bwt) was administered via nasogastric tube before i.v. fluid therapy. Two horses had mild abdominal discomfort at the end of enteral fluid therapy. Pollakiuria, hypostenuria, increased bodyweight, increased faecal and ingesta hydration, and decreased PCV, plasma protein and plasma magnesium were produced by both treatments. Abdominal distention and more pronounced changes in bodyweight and ingesta hydration were seen with enteral fluids. Intravenous fluids plus MgSO4produced hypocalcaemia and more pronounced changes in plasma protein. These results indicate that enteral fluid therapy is more effective in promoting ingesta hydration and produces less pronounced systemic effects than i.v. fluid therapy plus MgSO4.
High volume continuous venovenous haemofiltration (HV‐CVVH) in an equine endotoxaemic shock model
Authors: VEENMAN J. N. , DUJARDIN C. L. L. , HOEK A. , GROOTENDORST A. , KLEIN W. R. , RUTTEN V. P. M. G. 
Published: April 2007

SummaryEquine acute abdominal disease is often associated with shock. Important aspects in the onset of this complication include hypovolaemia, the translocation of endotoxins from the gut and the subsequent activation of the cytokine network. The clinical efficacy of high volume continuous venovenous haemofiltration (HV‐CVVH) and the clearance of cytokines were therefore investigated in an equine endotoxaemic model. Ten male Shetland ponies received a slow infusion of LPS (2 μg/kg bwt) under general anaesthesia. The treatment group (n = 5) received HV‐CVVH (2 ml/kg bwt/min) using a 75 kD polymethylmethacrylate (PMMA filter). Haemodynamic, blood variable and cytokine (TNF, IL‐1 and IL‐6) measurements were performed every 30 min for a 6 h period. The ponies showed a typical reaction in mean pulmonary arterial pressure, blood chemical and haematological markers after LPS challenge. No significant differences were found between the treatment group and the control group. Only a slight increase in cardiac index and no marked decrease in mean arterial pressure were seen. A clear cytokine response was found in all ponies, though substantially different in magnitude between individuals. The clearance of cytokines from the blood increased in time, but did not lead to significant decrease in serum levels. In this study, HV‐CVVH with a PMMA filter did not prove to have a significant beneficial effect on the course of experimental endotoxaemia in horses. However, in a more severe model, better efficacy might be obtained. Testing additional filters might lead to a more suitable therapy for horses.
The effects of xylazine, detomidine, acepromazine and butorphanol on equine solid phase gastric emptying rate
Authors: SUTTON D. G. M. , PRESTON T. , CHRISTLEY R. M. , COHEN N. D. , LOVE S. , ROUSSEL A. J. 
Published: April 2007

SummaryThe aim of this study was to measure the effects of specific commonly used sedative protocols on equine solid phase gastric emptying rate, using the13C‐octanoic acid breath test (13C‐OABT). The gastric emptying of a standard13C‐labelled test meal was measured once weekly in 8 mature horses over two 4 week treatment periods. Each horse acted as its own control. In treatmentPeriod 1, saline (2 ml i.v.), xylazine (0.5 mg/kg i.v.), detomidine (0.01 mg/kg i.v.) or detomidine/butorphanol combination (0.01/0.02 mg/kg i.v.) was administered in randomised order after ingestion of the test meal. During treatmentPeriod 2, test meal consumption was followed by saline, xylazine (1.0 mg/kg i.v.), or detomidine (0.03 mg/kg i.v.) administration, or preceded by acepromazine (0.05 mg/kg i.m.) in randomised order. The13C:12C ratio of sequential expiratory breath samples was determined by isotope ratio mass spectrometry, and used to measure the gastric half‐emptying time, t1/2, and duration of the lag phase, tlag, for each of the 64 tests.In treatmentPeriod 1, detomidine/butorphanol prolonged both t1/2and tlagwith respect to xylazine 0.5 mg/kg and the saline control (P<0.05). InPeriod 2, detomidine 0.03 mg/kg delayed each parameter with respect to saline, acepromazine and xylazine 1.0 mg/kg (P<0.001). Xylazine 1.0 mg/kg also lengthened tlagrelative to the saline control (P = 0.0004), but did not cause a significant change in t1/2. Comparison of treatment periods showed that the inhibitory effect of detomidine on gastric emptying rate was dose related (P<0.05). These findings may have clinical significance for case selection when these agents are used for purposes of sedation and/or analgesia.
In vitroinvestigation of the interaction between nitric oxide and cyclo‐oxygenase activity in equine ventral colon smooth muscle
Authors: VAN HOOGMOED L. M. , HARMON F. A. , STANLEY S. , WHITE J. , SNYDER J. 
Published: April 2007

SummaryThe objective of this study was to determine if a correlation exists between the presence of nitric oxide and prostaglandin release in the equine ventral colon smooth muscle, since this relationship may accentuate the inflammatory process during intestinal injury. Tissue was collected from the ventral colon, cut into muscle strips oriented along the circular, longitudinal and taenial layers, and mounted in a tissue bath system. Samples of the bath fluid were collected before, following electrical field stimulation (EFS), and following EFS in the presence of L‐NAME, a nitric oxide synthase inhibitor. Muscle strips were also obtained following systemic administration of a cyclo‐oxygnease inhibitor and samples were collected using the previously described protocol. Concentrations of prostaglandins were determined in the fluid samples using an ELISA. Electrical field stimulated release of nitric oxide produced a significant increase in prostaglandin production which did not occur in the presence of L‐NAME. Systemic administration of flunixin meglumine reduced prostaglandin levels at all sampling periods, although a small increase was present following EFS. The results of this study support the hypothesis that there is a correlation between the release of nitric oxide and the production of prostaglandins in the smooth muscle of the large colon. This association between nitric oxide and prostaglandin may act as an important regulatory mechanism for various physiological mechanisms, such as vascular smooth muscle tone, and may contribute to amplified tissue injury when the induced forms of both enzymes are activated during an inflammatory insult. This suggests that the use and development of COX2 and iNOS inhibitors may help attenuate the inflammatory response following intestinal injury.
Long‐term survival of equine surgical colic cases. Part 1: Patterns of mortality and morbidity
Authors: PROUDMAN C. J. , SMITH J. E. , EDWARDS G. B. , FRENCH N. P. 
Published: April 2007

SummaryPostoperative complications and mortality can occur many weeks or months after colic surgery. We are interested in the long‐term outcome of these cases. This study documents patterns of mortality and morbidity among 341 horses that recovered from colic surgery March 1998–August 2000. The progress of each horse was rigorously followed by periodic telephone and postal questionnaires. Event time data were recorded for each animal and a total of 321 horse years of survival, together with death from all causes, colic‐related death and various postoperative complications.Postoperative survival (of all horses excluding grass sickness cases) was triphasic over the first 600 days and there was marked mortality in the first 10 days postoperatively. The probability of survival postoperatively decreased to 0.87 by 10 days, 0.82 by 100 days and declined slowly to 0.75 at 600 days. Horses suffering from epiploic foramen entrapment had a significantly reduced probability of postoperative survival (RR = 2.1, P = 0.033). The causes of death for 104 horses that died postoperatively and the prevalence of postoperative complications are recorded for the study population. Postoperative colic was the most prevalent complication with 100 horses (29%) suffering one or more episodes. However, only 16 horses (4.6%) suffered 3 or more episodes. The incidence of postoperative colic was 0.55 episodes/horse year at risk. This study provides data that will inform the prognosis for postoperative colic cases and identifies epiploic foramen entrapment as carrying a worse prognosis for survival than other strangulating lesions.
Quantitative detection of atropine‐delayed gastric emptying in the horse by the 13C‐octanoic acid breath test
Authors: SUTTON D. G. M. , BAHR A. , PRESTON T. , COHEN N. D. , LOVE S. , ROUSSEL A. J. 
Published: April 2007

SummaryThe13C‐octanoic acid breath test has been correlated significantly to radioscintigraphy for measurement of gastric emptying indices in healthy horses. The objective of this study was to investigate the validity of the test for measurement of equine delayed gastric emptying, prior to its potential clinical application for this purpose. A model of atropine‐induced gastroparesis was used. Gastric emptying rate was measured twice in 8 horses using concurrent radioscintigraphy and/or breath test after treatment i.v. with either atropine (0.035 mg/kg bwt) or saline in randomised order.Analysis of both data sets demonstrated that the atropine treatment had caused a significant delay in gastric emptying rate. Paired breath test data showed an atropine‐induced delay in gastric half‐emptying time (t1/2), with no overlap in the 99% CI range (P<0.001). Significant correlations were found between scintigraphy and13C‐octanoic acid breath test for calculation of both t1/2(P<0.01) and lag phase duration (P<0.05) in the atropine‐delayed emptying results. The mean (s.d.) bias in breath test t1/2when compared with scintigraphy was 1.78 (0.58) h.The results demonstrated that the13C‐octanoic acid breath test was an effective diagnostic modality for the measurement of equine delayed gastric emptying. The technique offers advantages to existing methods for clinical investigation, as it is noninvasive, not radioactive, quantitative and requires minimal equipment or training to perform.
Long‐term survival of equine surgical colic cases. Part 2: Modelling postoperative survival
Authors: PROUDMAN C. J. , SMITH J. E. , EDWARDS G. B. , FRENCH N. P. 
Published: April 2007

SummaryColic surgery is a frequently performed operation with high postoperative mortality. This study was undertaken to identify variables associated with decreased postoperative survival. We used data from 321 horse years of postoperative survival time to model the probability of survival following recovery from colic surgery. Continuous variables were modelled using a 6 variable, penalised Cox regression model. This demonstrated approximately linear relationships between survival and the following variables: increase in packed cell volume (PCV), intestinal resection length, time to surgery (interval between onset of colic and surgery) and duration of surgery. No significant decrease in survival was demonstrated with increasing age of the patient or with heart rate. The only categorical variable to be significantly associated with decreased survival was epiploic foramen entrapment. The final, fixed effects Cox proportional hazards model of postoperative survival included the variables epiploic foramen entrapment, PCV, resection length and duration of surgery, each variable adjusted for the nonlinear relationship with time to surgery. Residual variation in postoperative survival attributable to professional personnel (referring veterinary surgeon, anaesthetist and surgeon) was explored by fitting each as a random effects term in the model. Little of the residual variation could be attributed to any category of personnel. Model diagnostics indicated little influence by individual outliers on model parameters and little evidence of subjects poorly predicted by the final model. The study highlights factors influencing the long‐term survival of horses recovering from colic surgery and proposes a model that can be used to inform prognosis.