bluuebunny/crossref_metadata_2025_split huggingface dataset:
A field study of patterns of unobserved foetal loss as determined by rectal palpation in foaling, barren and maiden Thoroughbred mares
Authors: GILBERT R. O. , MARLOW C. H. B. 
Published: April 2010

SummaryRecords of 1,009 pregnancies in 574 foaling, barren and maiden Thoroughbred mares on a single stud farm, over a period of 12 years were examined. The farm is situated in the eastern Cape Province of South Africa, at an elevation of 1,800 m, and in an area of climatic extremes. Records of 604 pregnancies in 249 foaling Thoroughbred mares were examined. For these purposes, those pregnancies in which a mare conceived in the same breeding season during which she had foaled were considered as pregnancies in foaling mares. Pregnancy was confirmed by rectal palpation by a single experienced practitioner. Of the 604 pregnancies examined, conceptus attachment occurred in the horn opposite the previously gravid horn in 345 cases (57%), and in the previously gravid horn in 259 cases (43%; P < 0.005). Unobserved foetal loss after pregnancy diagnosis amounted to 30 (9%) in the former group, while in the latter group (pregnancy established in the postgravid horn) 46 pregnancies were lost (18%; P< 0.005). This study confirmed that conceptus attachment tends to occur in the uterine horn opposite the previously gravid horn in foaling Thoroughbred mares conceiving during the same season. A significantly higher incidence of foetal loss accompanied conceptus attachment in the postgravid horn.Of 242 pregnancies in 162 previously barren mares, 95 (39%) occurred in the left uterine horn and 147 (61%) in the right horn (P < 0.005). The incidence of pregnancy failure in this group was 7%. The side of attachment did not affect the rate of loss. Evaluation of the records of 163 maiden mares revealed that conceptus attachment occurred in the left uterine horn in 58 (36%) pregnancies and in the right horn in 105 (64%) pregnancies (P< 0.005), which is consistent with previously reported observations. Pregnancy failure was recorded in 4% of maiden mares. Side of attachment did not influence rate of loss in this group.
Ultrasound speed in the metacarpal cortex — a survey of 347 Thoroughbreds in training
Authors: BUCKINGHAM S. H. W. , McCARTHY R. N. , ANDERSON G. A. , McCARTNEY R. N. , JEFFCOTT L. B. 
Published: April 2010

SummaryTransmission ultrasound speed was determined in the third metacarpal bone of 347 Thoroughbred racehorses in training. In addition to direct measurement of apparent ultrasound speed and lateral bone diameter, several derived parameters were estimated (cortical ultrasound speed, corticomedullary ratio and cortical cross‐sectional area). Multiple regression equations were developed for each ultrasound measurement using the explanatory variables: sex, age, duration and intensity of training, preparation number and previous shin soreness. The horses (114 females, 82 entire males and 151 geldings ranging in age from 20 to 116 months) had been in continuous training for an average of 10.0 weeks when measurements were made. All measurements except corticomedullary ratio were influenced by the sex of the horse. Geldings had significantly lower ultrasound transmission speed than entire males and females, reflecting a lower bone density. However, the geldings had larger cross‐sectional areas (ie bone size). We suggest that the relationship between low ultrasound speed (ie low bone density) and large cross‐sectional area maintains the overall mechanical integrity of the metacarpus. This relationship (high ultrasound speed and low cross‐sectional area) was also found in each sex group. Ultrasound speed and corticomedullary ratio, but not cross‐sectional area, were affected by age. Both duration and intensity of training influenced the ultrasound speed measurements. This study indicated that sex, age and state of training affect ultrasound results, but this explained only about 30% of the variance in the data. Other factors, ie genetic variation in bone density and size, differences in soft tissue thickness and distal limb temperature, presumably account for most of the variance.Acknowledgements. This project was sponsored by the Australian Equine Research Foundation and partly through a special grant from the Department of Sport and Recreation of Victoria. We thank Dr C. Savage and Dr H. Davies for assistance and advice; Mrs M. Jones and Mr A. Alder for technical help with the ultrasound measurements; and the many trainers who allowed access to the horses in their care.
Pulmonary artery and aortic pressure changes during high intensity treadmill exercise in the horse: effect of frusemide and phentolamine
Authors: ERICKSON B. K. , ERICKSON H. H. , COFFMAN J. R. 
Published: April 2010

SummaryIntravenous frusemide (1.0 mg/kg bwt) or phentolamine (0.33 mg/kg bwt) was given to 7 horses 1 h before exercise and their effects on pulmonary artery and aortic pressure changes during strenuous exercise were examined. Short‐term near‐maximal treadmill exercise (10 m/sec, 3° incline) produced increases in heart rate, mean pulmonary artery pressure (PAP), mean aortic pressure (AP), and packed cell volume (PCV). Frusemide did not affect heart rate, PAP or PCV during exercise. Frusemide significantly decreased mean AP by 10 to 15 mmHg during exercise. Phentolamine produced an increase in heart rate relative to control only early in exercise but not during later, more strenuous, exercise. Phentolamine had no statistically significant effect on AP, PAP or PCV, but a significant reduction was observed between 180 and 230 sec of exercise when PAP and AP were standardised against heart rate. Frusemide did not prevent horses from haemorrhaging during exercise in this study. Treatment with phentolamine did not sufficiently reduce the PAP and AP to test our hypothesis that a reduction in PAP and AP would eliminate EIPH.
Abortion of virologically negative foetuses following experimental challenge of pregnant pony mares with Equid herpesvirus 1
Authors: SMITH K. C. , WHITWELL KATHERINE E. , BINNS M. M. , DOLBY CHRISTINE A. , HANNANT D. , MUMFORD JENNY A. 
Published: April 2010

SummaryFrom 1988 to 1991, 51 pregnant pony mares were challenged intranasally or by aerosol with an isolate of EHV‐1 (AB4) originally recovered from a quadriplegic mare. This resulted in 32 abortions, occurring from 9 to 29 days after infection. In 14 of the early abortions (Days 9–14), EHV‐1 was not demonstrated in the foetal tissues by virus isolation or immunostaining despite no other non‐viral cause for the abortion being evident. Application of the polymerase chain reaction to foetal tissues from 9 of these cases also proved negative. One of the 14 mares was destroyed immediately after abortion, and post‐mortem examination revealed severe and widespread vasculitis, thrombosis and secondary ischaemic damage in the endometrium with replication of EHV‐1 in endothelial cells. These findings suggest that EHV‐1 abortion can occur due to endometrial damage without the establishment of a foetal infection.
Skeletal muscle characteristics in young trained and untrained Standardbred trotters
Authors: RONÉUS MERIKE , ESSÉN‐GUSTAVSSON BIRGITTA , LINDHOLM A. , PERSSON S. G. B. 
Published: April 2010

SummaryMuscle biopsies were taken from the middle gluteal muscle of 28 Standardbred trotters, 3–4 years of age. The 13 horses in Group T were trained consistently from 18 months of age, whereas the 15 horses in Group UT were not exposed to any systematic training before 3 years of age. Group T horses had a lower percentage of Type IIB fibres (31%) than did Group UT horses (39%). Citrate synthase (CS) activity, representing oxidative capacity, was higher in Group T (72 mmol kg−1min−1) than in Group UT (47 mmol kg−1min−1). Biopsies were taken from 4 horses in each group when they were foals and then annually until 3–4 years of age. Results from this study indicate that regular training of Standardbreds from 18 months of age resulted in increased CS activity and a decrease in the percentage of Type IIB fibres. This study shows that training, not growth, is the main factor that induces a high oxidative capacity and a high Type IIA/IIB fibre ratio in muscle of Standardbred trotters.
Five cases of gastrocnemius tendinitis in the horse
Authors: DYSON SUE J. , KIDD LISA 
Published: April 2010

SummaryThe normal gastrocnemius tendon may contain some muscular tissue proximally. This results in a patchy echogenicity ultrasonographically where it lies caudal or lateral to the superficial digital flexor tendon (SDFT). When it has assumed a position dorsal (cranial) to the SDFT the gastrocnemius tendon has a more uniform echogenicity and its margins are well defined. Five horses had lameness associated with lesions identified ultrasonographically in the gastrocnemius tendon in the latter region. Lameness ranged from mild to severe and was characterised by reduced hock flexion, lowered arc of foot flight, shortened length of the cranial phase of the stride and in some horses a reduced duration of weight bearing during the caudal phase of the stride. Lameness was variably accentuated by flexion of the proximal or distal limb joints of the lame limb. Perineural analgesia of the tibial and fibular nerves or the tibial nerve alone substantially improved the lameness. All horses remained lame 2–3 months after initial examination, with minimal change in the ultrasonographic appearance of the lesion(s).
Retrospective study of 38 cases of femur fractures in horses less than one year of age
Authors: HANCE S. R. , BRAMLAGE L. R. , SCHNEIDER R.K. , EMBERTSON R. M. 
Published: April 2010

SummaryMedical records of 38 horses <1 year of age and diagnosed as having a fracture of the femoral diaphysis, metaphysis or distal physis were evaluated. Twenty‐six foals had fractures of the femoral diaphysis or metaphysis with the most common fracture configuration being comminuted. Twelve foals had distal physeal fractures with the most common fracture configuration being a Salter‐Harris type II. Twenty‐one foals with fractures of the capital femoral physis, neck or greater trochanter during the same time period were excluded from this study. Surgical repair was attempted in 16 diaphyseal and 2 distal physeal fractures. Most of the diaphyseal fractures were repaired by placing plates on the lateral and cranial surfaces of the bone. Dynamic condylar screw plates or angle blade plates were used for increased bone purchase in 4 foals with short distal fragments. Five foals with distal physeal fractures were treated; 2 were surgically treated by placing an angle blade plate on the lateral cortex, and 3 foals with minimally displaced distal physeal fractures were managed with stall confinement. Eight of the 16 surgically repaired diaphyseal fractures healed. Fracture location and configuration was not a determinant of outcome, but the mean age of foals with successfully repaired diaphyseal fractures was 2 months compared with 4 months for the unsuccessful cases, indicating that the age and size of the foal was important. Long‐term follow up revealed that 6 of the 8 successfully repaired diaphyseal fractures had no residual effects of the fracture observed during performance of the horse for its intended use. Only 1 of the 2 surgically repaired distal physeal fractures healed, but this horse was eventually killed because of unthriftiness related to a malabsorption syndrome. Some form of complication developed in 13 of the 18 surgically repaired fractures. Infection was the primary cause of failure. The greatest determinant associated with infection was the inability to control post‐surgical seroma formation.
Arachidonate metabolites in bronchoalveolar lavage fluid from horses with and without COPD
Authors: WATSON ELAINE D. , SWEENEY C. R. , STEENSMA K. A. 
Published: April 2010

SummaryArachidonate metabolites were measured in bronchoalveolar lavage fluid (BALF) from horses with (N = 4) and without (N = 7) chronic obstructive pulmonary disease (COPD). Prostaglandin (PG) D2, leukotriene (LT) B4and LTC4were present in highest concentrations in BALF from clinically normal horses. Concentrations of PGE2and PGF were significantly higher in BALF from horses with COPD than in BALF from normal horses, but no differences were detected in thromboxane B2, 6‐keto‐PGF1α, PGD2, LTB4or LTC4.
Arthroscopic surgery for osteochondritis dissecans of the femoropatellar joint of the horse
Authors: FOLAND J. W. , McILWRAITH C. W. , TROTTER G. W. 
Published: April 2010

SummaryArthroscopic surgery for the treatment of osteochondritis dissecans was undertaken on 252 femoropatellar joints in 161 horses (82 Thoroughbreds, 39 Quarter Horses, 16 Arabians, 9 Warmbloods and 15 others of various breeds). There were 53 females and 108 males. Twenty‐two horses were 1 year of age at the time of surgery, 68 were yearlings, 36 were 2‐year‐olds, 21 were 3‐year‐olds, and 14 were ≤4 years old. Ninety‐one had bilateral involvement and 70 had unilateral disease. Follow‐up information was obtained on 134 horses, including 79 racehorses and 55 non‐racehorses: 86 (64%) of these 134 horses returned to their intended use, 9 (7%) were in training, 21 (16%) were unsuccessful and 18 (13%) were unsuccessful due to other defined reasons. Horses with Grade I lesions (<2 cm in length) had a significantly higher success rate (78%) than did horses with Grade 2 (2–4 cm) or Grade 3 (>4 cm) lesions (63% and 54% success rates respectively). A significantly higher success rate was also noted for horses operated on as 3‐year‐olds compared with the remainder of the study population. A significantly lower success rate was noted for yearlings than for the remainder of the population. There was no significant difference in outcome as related to sex of animal involved, racehorse versus non‐racehorse, lesion location, unilateral versus bilateral involvement, presence or absence of patellar or trochlear groove lesions, or presence or absence of loose bodies.
Muscle histopathology and plasma aspartate aminotransferase, creatine kinase and myoglobin changes with exercise in horses with recurrent exertional rhabdomyolysis
Authors: VALBERG STEPHANIE , JÖNSSON L. , LINDHOLM A. , HOLMGREN N. 
Published: April 2010

SummarySix horses with a history of recurrent exertional rhabdomyolysis (RER) (Horses A‐F) and 7 control horses performed a submaximal and later a near‐maximal treadmill exercise test. Blood samples were obtained before, during and after exercise and muscle biopsies were taken before and after exercise. At rest, plasma aspartate aminotransferase (AST) activities in horses with RER were above 95% confidence intervals for control horses. During submaximal exercise, 3 horses with RER (A, B and C) had much greater increases in plasma AST, creatine kinase (CK) and myoglobin concentrations than did Horses D, E and F and control horses. Clinical signs of muscle stiffness and pain were only obvious in Horse A. During near‐maximal exercise, only Horse C showed a substantial increase in CK activity and myoglobin concentrations without any associated clinical signs of rhabdomyolysis. Muscle biopsies from Horses A, B and C contained necrotic type II fibres which, on electron microscopic examination, contained disrupted myofibrils and swollen mitochondria. These results suggest that, in RER, subclinical episodes of muscle fibre necrosis and associated increases in plasma AST, CK and myoglobin occur with exercise more frequently than could be detected clinically. Furthermore, the pattern of increase in muscle enzymes and myoglobin concentrations in the 6 horses with RER suggested that the high plasma AST and CK activities commonly observed at rest in symptom‐free Standardbred horses are probably a result of repeated subclinical episodes of rhabdomyolysis after exercise, rather than leakage due to abnormal sarcolemmal permeability.
Blood chemistry and skeletal muscle metabolic responses to exercise in horses with recurrent exertional rhabdomyolysis
Authors: VALBERG STEPHANIE , HÄGGENDAL J. , LINDHOLM A. 
Published: April 2010

SummarySix horses with a history of recurrent exertional rhabdomyolysis (RER) and 7 control horses performed both a 55‐min submaximal and later a 10‐min near‐maximal exercise test on a treadmill. Blood samples were obtained during exercise and gluteus medius muscle biopsies were obtained before and immediately after each exercise test and at 24 h after completion of the submaximal test. Rhabdomyolysis was developed by 3 of 6 RER horses during submaximal exercise and in 1 of the RER horses during near‐maximal exercise. Concentrations of potassium, glucose, free fatty acids, ammonia, lactate, cortisol, adrenaline and noradrenaline in the blood were measured. None of these variables appeared useful in predicting which RER horses would develop rhabdomyolysis. The RER horses that developed rhabdomyolysis (RERa) had higher Cortisol and blood glucose concentrations but otherwise had blood chemistry and muscle metabolic responses during submaximal and near‐maximal exercise similar to those of RER horses which did not develop rhabdomyolysis (RERb) and to controls. At rest, muscle glycogen concentrations were significantly higher (>650 mmol/kg dry wt) in RERa and RERb horses than in controls. Lactate concentrations in muscle after submaximal and near‐maximal exercise were similar or lower, respectively, in RERa horses compared with controls. The results of this study indicate that, although horses with RER had high resting intramuscular glycogen concentrations, rhabdomyolysis did not appear to be caused by an excessively rapid rate of anaerobic glycolysis with lactate accumulation.
An investigation of injection techniques for local analgesia of the equine distal tarsus and proximal metatarsus
Authors: DYSON SUE J. , ROMERO J. M. 
Published: April 2010

SummaryA positive radiographic contrast agent was injected into the tarsometatarsal (TMT) joints of both hindlimbs of 10 horses. Lateromedial radiographic views were obtained at 5, 15 and 30 mins after injection. Injection was successful in 19 of 20 limbs. Communication between the centrodistal (CD) and TMT joints was identified in 7 limbs (35%). Contrast agent extended around the tendons of tibialis cranialis (TC) and fibularis tertius (FT) in 18 limbs, and in 7 limbs some contrast entered the tarsal sheath. Slight to moderate plantar and/or distal extension of contrast agent was identified in 13 limbs. On a subsequent occasion positive contrast agent was injected subtarsally using one of two techniques and radiography was repeated. Contrast agent was principally distributed on the plantar aspect of the 3rd metatarsal bone, the plantar aspect of the suspensory ligament and between the superficial and deep digital flexor tendons. Extension of contrast agent into the TMT joint was identified in only 1 limb but in 8 limbs contrast agent extended into the tarsal sheath.The practical implications of these results include the possibility that local anaesthetic solution injected into the TMT joint may alleviate pain from the CD joint, the insertions of TC and FT or the tarsal sheath. It may also result in perineural analgesia of the dorsal metatarsal nerves or the plantar metatarsal nerves. In some cases subtarsal injection of local anaesthetic solution may result in alleviation of pain from the tarsal sheath. False negative results for subtarsal analgesia may be achieved by inadvertent injection into the tarsal sheath or into a blood or lymphatic vessel.
An immunohistological study of the uterus of mares following experimental infection by Equid herpesvirus 1
Authors: SMITH K. C. , WHITWELL KATHERINE E. , MUMFORD JENNIFER A. , GOWER SUSAN M. , HANNANT D. , TEARLE J. P. 
Published: April 2010

SummaryTwelve Welsh Mountain pony mares in late gestation were infected intranasally with EHV‐1 (AB4 isolate) at dose rates from 103 to 107.3 TCID50. This resulted in 3 cases of paresis, at Days 9, 10 and 12 after inoculation, and 5 abortions, at Days 6, 9, 18, 19 and 20. Euthanasia was performed between Days 6 and 21, with collection of uterine specimens for histopathology, virus isolation and immunoperoxidase staining from the pregnant horn, non‐pregnant horn and body. EHV‐1 replication in endometrial vessels was detected as early as Day 6 and was maximal at Days 9–11, when widespread thromboischaemic damage was present. By Days 15–19 in mares remaining pregnant, EHV‐1 antigen expression in the endometrium was sparse, despite residual lesions but little associated thrombosis. Endometrial vascular pathology varied considerably in degree and extent, and no consistent predilection sites for replication within the uterus were apparent.
Clinical evaluation of an infusion of xylazine, guaifenesin and ketamine for maintenance of anaesthesia in horses
Authors: YOUNG LESLEY E. , BARTRAM D. H. , DIAMOND MANDY J. , GREGG ANNE S. , JONES R. S. 
Published: April 2010

SummaryGeneral anaesthesia was maintained in 40 horses by the continuous intravenous infusion of a mixture of 500 ml 10% guaifenesin solution, 1 g ketamine and 500 mg xylazine. The median duration of infusion was 65 mins (interquartile range 51–95 mins). Anaesthesia was characterised by active palpebral reflexes, variable degrees of nystagmus and occasional swallowing. Swallowing was considered to be undesirable in horses undergoing laryngeal surgery, but the infusion produced satisfactory conditions for all other surgical procedures performed. Arterial blood pressure was well maintained in all cases (median mean arterial blood pressure = 85 mmHg after 30 mins anaesthesia). Heart rate andPaCO2were significantly lower, whilstPaO2was significantly higher in the infusion group than in a group of paired control horses which were anaesthetised with halothane. Recovery from anaesthesia was good (Grades 1–2) in 33 horses. Median times to sternal recumbency and to standing were 24 and 38 mins respectively. The infusion caused a significant fall in packed cell volume, haemoglobin concentration and red blood cell count (P<0.01) and a significant rise in plasma glucose concentration (P<0.01). These variables returned to pre‐infusion values within 24 h.
Communication of the ulnaris lateralis bursa with the equine elbow joint and evaluation of caudal arthrocentesis
Authors: SAMS A. E. , HONNAS C. M. , SACK W. O. , FORD T. S. 
Published: April 2010

SummaryElbows from cadaver limbs were evaluated to determine the presence of a communication between the ulnaris lateralis bursa (ULB) and the joint and the extent of the bursa. Thirty‐two pairs of joints were studied: 12 pairs were frozen, then transversely sectioned and 20 pairs were injected with methyl methacrylate.The 12 frozen‐section pairs revealed a communication between the ULB and the elbow joint in 9/24 joints (37.5%) and a true bursa (absence of communication) in 15/24 joints (62.5%). The mean bursal length in adult horses was 3.8 cm. There was no significant difference in the length of the bursa or presence of bursa‐joint communication between the right and left limbs. In the acrylic specimens a communication between the ULB and the joint was found in 19/40 specimens (47.5%). There was no significant correlation between age or sex and frequency of communication. There was a significantly greater prevalence of communications present in Quarter Horse than in non‐Quarter Horse (P < 0.05) joints. A communication between the ULB and the joint is not always present, and therefore injection of the elbow joint via the ULB may be unreliable.