bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dose responses to inhalation of endotoxin, hay dust suspension andAspergillus fumigatusextract in horses as measured by levels and activation of matrix metalloproteinase‐9
Authors: SIMONEN‐JOKINEN T. , PIRIE R. S. , McGORUM B. , MAISI P. 
Published: April 2007

SummaryReasons for performing study: Airway matrix metalloproteinases (MMPs) increase after endotoxin (LPS) exposure, but there are no reports describing dose‐dependent increases or activation following exposure.Objectives: To study matrix metalloproteinase‐9 (MMP‐9) and ‐2 (MMP‐2) responses in bronchoalveolar lavage fluid (BALF) from heaves‐susceptible and control horses following inhalation of hay dust suspension (HDS), LPS andAspergillus fumigatusextract (AFE).Methods: Heaves‐susceptible (n = 7) and control (n = 6) horses received inhalation challenges with 3 different doses of HDS and LPS. Heaves‐susceptible horses (n = 6) also received 3 different doses of AFE and one dose of AFE depleted of endotoxin (AFE‐LPS). BALF collected following inhalation challenges was analysed using gelatin zymography. Gelatinolytic bands were identified as complex, pro‐MMP‐9, active MMP‐9, pro‐MMP‐2 and active MMP‐2 based on molecular weights.Results: Each challenge substance induced a dose‐dependent elevation in gelatinolytic activity. The dose‐dependency was most evident for pro‐MMP‐9 and total MMP‐9 levels in heaves‐susceptible horses following LPS challenges.Conclusions: There is a dose‐dependent elevation in MMP‐9 in BALF of heaves‐susceptible and control horses following inhalation challenge with organic dust and some of its components, elevation being more marked in heaves‐susceptible horses. Organic dust components vary in their pro‐inflammatory potential.Potential relevance: This study supports the role of MMPs in the pathogenesis of heaves and highlights the potential value of protease inhibitors in attenuating the airway inflammatory response to inhaled organic dust.
Lameness associated with foot pain: results of magnetic resonance imaging in 199 horses (January 2001‐December 2003) and response to treatment
Authors: DYSON S. J. , MURRAY R. , SCHRAMME M. C. 
Published: April 2007

Summary Reasons for performing study: The diagnosis of foot‐related lameness often remains elusive and it can be difficult to offer rational treatment, or to predict outcome. Objectives: To describe the spectrum of injuries of the foot identified using magnetic resonance imaging (MRI), to determine their relative prevalence among MRI diagnoses and to establish the long‐term results of treatment. Methods: The MR images of horses examined from January 2001‐December 2003 were reviewed. Horses were selected for MRI if the pain causing lameness was localised to the foot using perineural analgesia but any clinical, radiological or ultrasonographic abnormalities were insufficient to explain the degree of lameness. The clinical significance of lesions identified using MRI was determined with reference to the results of local analgesia, radiography, ultrasonography and nuclear scintigraphy.Follow‐up information was obtained in January 2004 for horses which had been examined 6‐36 months previously and the outcome classified as excellent (horse returned to full athletic function without recurrent lameness), moderate (sound, but only in light work), or poor (persistent or recurrent lameness). Results: One hundred and ninety‐nine horses underwent MRI examinations. Deep digital flexor (DDF) tendonitis was the most common injury (59%) with primary injury in 65 horses (33%) and a further 27 horses (14%) having lesions of the DDF tendon and navicular bone. Seventeen percent of horses had injuries to multiple structures, including 24 with DDF tendonitis. Desmitis of a collateral ligament (CL) of the distal interphalangeal (DIP) joint was the second most common injury (62 horses, 31%), with primary injuries in 30 horses (15%) and a further 32 horses (16%) that had CL desmitis in conjunction with other injuries.Prognosis was best for horses with traumatic injuries of the middle or distal phalanges, with 5 of 7 horses (71%) having an excellent outcome. Horses with primary lesions of the DDF tendon or CL of the DIP joint had excellent results in only 13 of 47 (28%) and 5 of 17 horses (29%), respectively. Horses with combined injuries of the DDF tendon and navicular bone, or primary navicular bone abnormalities, had a poor outcome, with the majority of horses suffering persistent lameness. Conclusions: A wide variety of lesions associated with foot pain were identified using MRI, a high proportion of which were primary soft tissue injuries with a guarded prognosis for return to full athletic function. Potential relevance: It is now possible to propose more rational treatment strategies for the variety of foot injuries identified using MRI than had previously been possible; however, further information concerning aetiopathogenesis of these injuries is needed to improve their management.
Standing oral extraction of cheek teeth in 100 horses (1998‐2003)
Authors: DIXON P. M. , DACRE I. , DACRE K. , TREMAINE W. H. , McCANN J. , BARAKZAI S. 
Published: April 2007

Summary Reasons for performing study: Extraction of cheek teeth (CT) by the conventional repulsion technique requires general anaesthesia and carries a high rate of post operative complications. Consequently, an alternative method of extraction, i.e. orally in standing horses, was evaluated. Hypothesis: The need for and risks of general anaesthesia could be avoided and post extraction sequelae reduced by performing extractions orally in standing horses. Methods: One hundred mainly younger horses (median age 8, range 2‐18 years) with firmly attached CT that required extraction because of apical infections, displacements, diastemata, idiopathic fractures and the presence of supernumerary CT had the affected teeth (n = 111) extracted orally under standing sedation. Follow‐up information was obtained for all cases, a median of 16 months later. Results: Oral extraction was successful in 89 horses and unsuccessful in 11 due to damage to the CT clinical crown (n = 9) during extraction, for behavioural reasons (n = 1) and because the apex of a partly extracted CT fell back into the alveolus following sectioning (n = 1). Predispositions to extraction‐related CT fractures were present in 5 of the 9 cases, i.e. advanced dental caries (n = 2) and pre‐existing ‘idiopathic’ fractures (n = 3). The iatrogenically fractured CT were later repulsed under standing sedation (n = 3) and under general anaesthesia (n = 6).Eighty‐one of the remaining 89 horses had successful oral CT extraction with no or minimal intra‐ or post operative complications occurring. Post operative complications in the other 8 cases included post extraction alveolar sequestration (n = 3), alveolar sequestration and localised osteomyelitis (n = 1), localised osteomyelitis (n = 1), incorporation of alveolar packing material into alveolar granulation tissue (n = 1), and nasal discharge due to continued intranasal presence of purulent food material (n = 1) and to ongoing sinusitis (n = 1). The above sequelae were treated successfully in all cases, with general anaesthesia required in just one case. Following oral extraction, significantly (P<0.001) fewer post operative problems developed in 54 horses with apically infected CT in comparison with 71 previous cases that had repulsion of apically infected CT at our clinic. Conclusions and potential relevance: Oral extraction of cheek teeth is a successful technique in the majority of younger horses with firmly attached CT and greatly reduces the post operative sequelae, compared with CT repulsion. Additionally, the costs and risks of general anaesthesia are avoided. Further experience and refinement in the described protocol could potentially increase the success of this procedure and also reduce the incidence of post operative sequelae.
Deep digital flexor tendon force and digital mechanics in normal ponies and ponies with rotation of the distal phalanx as a sequel to laminitis
Authors: McGUIGAN M. P. , WALSH T. C. , PARDOE C. H. , DAY P. S. , WILSON A. M. 
Published: April 2007

Summary Reasons for performing study: Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6‐13° of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at trot using forceplate and motion analysis. The force in the DDFT was calculated by assuming that the extending moment at the distal interphalangeal (DIP) joint resulting from the GRF was equal to the flexing moment created by the force in the DDFT during the stance phase (inverse dynamics). Results: In early stance, the peak DDFT force (mean ± s.d.) in the normal ponies was 1.92 ± 1.63 N/kg. However, in Group 2, the point of zero moment was palmar to the centre of rotation of the DIP joint for the first 40% of stance and hence DDFT force was zero. Force in the DDFT reached a peak of 10.00 ± 3.56 N/kg at 60.7 ± 5.6% of stance in Group 1 and 6.41 ± 1.37 N/kg at 79.2 ± 9.6% of stance in Group 2. Conclusions: DDFT force in Group 2 laminitic ponies was much reduced until late stance, when it neared normal values. Potential relevance: Further studies of ponies with rotation of the DP as a sequel to laminitis should assist farriery aimed at reducing the force in the DDFT through the breakover phase of stance to protect damaged dorsal laminae.
Atropine reduces dobutamine‐induced side effects in ponies undergoing a pharmacological stress protocol
Authors: SANDERSEN C. F. , DETILLEUX J. , DELGUSTE C. , PIERARD L. , van LOON G. , AMORY H. 
Published: April 2007

Summary Reasons for performing study: High‐dose dobutamine stress echocardiography has been shown to be cardiotoxic and arrhythmogenic in horses. However, the test may have benefit in practice as a pharmacological challenge of exercise without the treadmill being required. Objectives: To investigate the effect of low‐dose dobutamine on cardiac performance in ponies previously treated with atropine, in order to develop a pharmacological protocol that allows examination of the equine heart under stimulation. Methods: In 13 healthy Shetland ponies, heart rate (HR), stroke index (SI) and cardiac index (CI) were calculated from pulsed‐wave Doppler ultrasound measurements performed at rest and during incremental steps of dobutamine infusion. Group 1 (n = 7) received dobutamine infusion at 2 μg/kg bwt/min for 5 mins followed by incremental rates of 5 μg/kg bwt/min every 5 mins, from 5 to 40 μg/kg bwt/min. Group 2 (n = 6) received dobutamine infusion in incremental rates of 1 μg/kg bwt/min, every 5 mins, from 2 μg/kg bwt/min to 5 μg/kg bwt/min, after premedication with 2 injections of 25 μg/kg bwt of atropine 5 mins apart. Results: The increase in CI during the pharmacological challenge was higher in Group 2 and reached about 2.5 times the resting value. This increase in CI was mediated by a significant increase in HR in both groups, while SI significantly decreased in Group 1 and did not change significantly in Group 2. Ponies of Group 1, but not those of Group 2, showed excessive restlessness and cardiac arrhythmias during the pharmacological challenge and a high intragroup variability in cardiac response. Conclusions: The results of this study suggest that a low dose of dobutamine in ponies previously given atropine could be a helpful pharmacological protocol to perform stress echocardiography in equids. Potential relevance: Further studies should evaluate left ventricular wall motion in horses undergoing low‐dose dobutamine protocol after pretreatment with atropine.
Biochemical markers of bone metabolism and risk of dorsal metacarpal disease in 2‐year‐old Thoroughbreds
Authors: JACKSON B. F. , LONNELL C. , VERHEYEN K. L. P. , DYSON P. , PFEIFFER D. U. , PRICE J. S. 
Published: April 2007

Summary Reasons for performing study: Dorsal metacarpal disease (DMD) is a common problem in 2‐year‐old racehorses and results in loss of a significant number of days from training. Biochemical markers of bone cell activity measured early in the training season could have value for identifying 2‐year‐old Thoroughbred racehorses that develop DMD. Objectives: To determine the association between serum concentrations of osteocalcin, the carboxyterminal propeptide of type I collagen (PICP) and the carboxyterminal cross‐linked telopeptide of type I collagen (ICTP) measured early in the training season and the risk of DMD. Methods: Blood samples were collected from 165 two‐year‐old Thoroughbreds during late November/early December. Osteocalcin and PICP were measured as markers of bone formation, and ICTP as a marker of bone resorption. Training and veterinary records for each horse were monitored over the following training/racing season (10 months). Cases were defined as an episode where signs of DMD were sufficiently severe for a horse to miss at least 5 consecutive days of training. Classification tree and logistic regression analysis were used to identify the most important factors suitable for prediction of DMD risk. Results: There were 24 cases of DMD during the season (14.6% cumulative incidence), with an average time to recognition of approximately 6 months (May). The earliest recognised case was in February and the latest in September. Osteocalcin and ICTP concentrations in the early stages of the training season were significantly higher in horses that subsequently developed DMD (P = 0.017 and 0.019, respectively). DMD cases were also significantly older compared to noncases (21.04 vs. 20.44 months, P = 0.023). Using a multivariable logistic regression model, it was possible to postulate a set of diagnostic rules to predict the likelihood of DMD injury during the season. This suggested that horses with ICTP concentrations above 12.365 ug/l and older than 20.5 months are 2.6 times more likely to develop DMD. Conclusions: The measurement of the bone resorption marker ICTP could be useful for identification of 2‐year‐olds at increased risk of developing DMD. Potential relevance: These findings, together with other strategies such as modification of training regimens, e.g. early introduction of short distances of high‐speed exercise into the training programme, could help reduce the days lost to training as a result of DMD.
Analysis of cartilage oligomeric matrix protein (COMP) degradation and synthesis in equine joint disease
Authors: ARAI K. , MISUMI K. , CARTER S. D. , SHINBARA S. , FUJIKI M. , SAKAMOTO H. 
Published: April 2007

Summary Reasons for performing study: Cartilage oligomeric matrix protein (COMP) is abundant within cartilage; its turnover and/or degradation have been investigated in various equine joint diseases and it has been suggested that COMP fragmentation might be useful for monitoring such conditions. Objectives: To determine whether COMP metabolism is compromised in equine osteoarthritis (OA) and whether COMP degradation is a useful joint marker representing cartilage destruction. Hypothesis: A monoclonal antibody (mAb) with a higher affinity for degraded COMP allows discrimination of diseased joints by quantifying COMP levels and fragmentation. Methods: A mAb (clone14G4) was generated against equine cartilage COMP. The NH2‐terminal sequence of enzyme‐cut COMP fragments recognised by 14G4 was determined, as was the efficiency of binding to COMP (using a generated COMP peptide). COMP concentration and fragmentation were analysed in synovial fluid (SF) from normal horses and those with OA. Results: The mAb 14G4 had a higher affinity for the smaller fragments of equine COMP, compared with a mAb (clone 12C4) generated against human COMP. The 14G4 epitope was identified as between C134 and F147. The COMP values in OA (mean ± s.d. 205.8 ± 90.9 μg/ml) were significantly higher than in the normal (133.1 ± 31.5 μg/ml) SF. On the immunoblots of OA sample, the proportions of intact COMP were significantly lower, while smaller fragments ranging from 75 to 290 kDa were higher compared with the normal SF. Conclusions and potential relevance: The mAb 14G4 reliably detects COMP degradation as well as synthesis, and fragmentation analysis combined with quantification in SF could be useful to study equine OA.
Immunoglobulin and peripheral B‐lymphocyte concentrations in Fell pony foal syndrome
Authors: THOMAS G. W. , BELL S. C. , CARTER S. D. 
Published: April 2007

Summary Reasons for performing study: Fell pony foals are affected by a congenital fatal disease that leads to profound anaemia and immunodeficiency. Previous studies comparing healthy and affected foals have shown normal T‐cell populations, but a severe B‐lymphopenia. Objectives: To measure the levels of individual immunoglobulin subisotypes in normal and affected Fell ponies and correlate these levels with the number of peripheral B‐lymphocytes. Methods: Serum levels of individual immunoglobulin subisotypes were measured by ELISA and correlated with the number of peripheral B‐lymphocytes (measured by flow cytometry). Results: Affected foals had significantly reduced serum levels of IgM, IgGa, IgGb and IgG(T) that coincided with the normal reduction in maternally derived immunoglobulin in foals and, with the exception of IgGb, correlated strongly with the B‐lymphopenia. Conclusions: These data suggest that affected foals are unable to produce their own immunoglobulins. Therefore, once maternal immunity has waned, it may be the lack of specific foal‐derived immunoglobulin that gives rise to the clinical signs of immunodeficiency. Potential relevance: Measurement of IgM after age 4 weeks may provide a more accessible means of confirming the status of future affected Fell pony foals than the measurement of B‐lymphocytes (a technique limited to a few specialist laboratories).
The influence of head and neck position on kinematics of the back in riding horses at the walk and trot
Authors: RHODIN M. , JOHNSTON C. , HOLM K. ROETHLISBERGER , WENNERSTRAND J. , DREVEMO S. 
Published: April 2007

SummaryReasons for performing study: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively.Objectives: To evaluate the effect of head and neck position on the kinematics of the back in riding horses.Methods: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3‐dimensional movement of the thoracolumbar spine was measured from the position of skin‐fixed markers recorded by infrared videocameras.Results: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion‐extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position.Conclusions: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced.Potential relevance: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back.
Three‐dimensional kinematics of the equine distal forelimb: effects of a sharp turn at the walk
Authors: CHATEAU H. , DEGUEURCE C. , DENOIX J. ‐M. 
Published: April 2007

SummaryReasons for performing study: Sharp turns are suspected to increase expression of several distal forelimb lamenesses even at the walk but the biomechanical consequences of such a movement remain unknown.Objective: To quantify the effects of a sharp turn at the walk on the 3‐dimensional movements of the distal segments of the forelimb.Methods: Kinematics of the distal segments were measured in 4 healthy horses invasively with an ultrasonic system. Three‐dimensional rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained for a turn at the walk were compared to those obtained in a straight line.Results: During the stance phase in a turn, the inside forelimb underwent an adduction that induced lateromotion and medial rotation in the distal interphalangeal joint and medial rotation in the proximal interphalangeal joint. These movements were maximal at heel‐off and decreased during breakover as the hoof underwent a sudden lateral rotation.Conclusions: Walking in a sharp turn affects the kinematics of the digital joints outside the sagittal plane.Potential relevance: This knowledge offers the opportunity to derive hypotheses on biomechanical factors that could contribute to the pathogenesis of digital injuries and on consequences for rational shoeing.
Colorectal distention in the horse: visceral sensitivity, rectal compliance and effect of i.v. xylazine or intrarectal lidocaine
Authors: SANCHEZ L. C. , MERRITT A. M. 
Published: April 2007

Summary Reasons for performing study: Most current models of visceral sensitivity testing in the horse have required visceral cannulation. Colorectal distention (CRD) is a widely used, noninvasive method for testing in other species and could be adapted for use in horses. Objectives: To develop a protocol of controlled CRD in the conscious horse and to evaluate the effect of i.v. xylazine or intrarectal lidocaine on CRD threshold and rectal compliance. Methods: Eight horses were used for baseline studies (3 trials each) and 6 horses to evaluate treatments (4 trials, 2 per treatment). A 45 cm diameter polyvinyl balloon attached to plastic tubing was used for rectal distention following a stepwise barostat‐controlled inflation pattern. Results: The procedure was well tolerated by all horses. Mean baseline threshold pressure was 14.17 mmHg. Xylazine i.v. resulted in significantly (P<0.05) higher mean threshold pressures compared to baseline or rectal lidocaine. Rectal compliance increased following lidocaine treatment relative to baseline or xylazine. Conclusions: CRD offers a noninvasive method for visceral sensitivity testing in the horse. Xylazine raises CRD threshold, while lidocaine increases rectal compliance. Potential relevance: The increased rectal compliance following intrarectal lidocaine administration may explain the benefit of its use to facilitate rectal examination.