bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Arthroscopic 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

Six 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

Six 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

A 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

Twelve 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

General 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

Elbows 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.
Ground reaction force patterns of Dutch Warmblood horses at normal trot
Authors: MERKENS H. W. , SCHAMHARDT H. C. , VAN OSCH GEERTRUDA J. V. M. , VAN DEN BOGERT A. J.
Published: April 2010

This study was undertaken to establish limb loading patterns of sound horses at the trot, to provide a data base against which results for lame horses could be compared. Ground reaction force (GRF) data were collected from 20 clinically sound Dutch Warmblood horses. The data from at least 5 stance phases of each limb were averaged after standardisation to the animal's body mass and to the stance phase duration and resulted in ‘representative’ GRF data. The symmetry in the vertical GRF peak amplitudes, impulses and the stance phase duration comparing left and right limbs exceeded 97%. By averaging the ‘representative’ GRF of the 20 horses a ‘standard’ GRF pattern of the Dutch Warmblood horse at the trot was constructed. The GRF patterns at the trot, compared with those at the walk, showed only one vertical force peak in forelimbs and hindlimbs (11.59 N/kg and 10.21 N/kg, respectively). The retardatory and propulsory forces were distributed over the forelimbs and hindlimbs in such a way that the forelimbs contributed more to retardation (peak forces 1.13 and 0.79 N/kg), and the hindlimbs more to propulsion (−0.84 and −1.17 N/kg, respectively).
Flunixin meglumine blocks frusemide‐induced bronchodilatation in horses with chronic obstructive pulmonary disease
Authors: RUBIE S. , ROBINSON N. E. , STOLL M. , BROADSTONE R. V. , DERKSEN F. J.
Published: April 2010

Six horses that developed acute airway obstruction (heaves) when housed in a barn and fed poor‐quality hay were studied. Airway obstruction was verified by a maximal change in pleural pressure during tidal breathing (ΔPplmax) of at least 15 cmH2O. Frusemide (1.0 mg/kg bwt) or an equivalent volume of vehicle was then administered intravenously (iv) and lung function was measured 15, 30, 60, 120, 180, 240 and 300 mins after drug administration. The effect of frusemide on lung function was also studied after treatment of horses with the cyclooxygenase inhibitor flunixin meglumine (1.1 mg/kg every 8 h for 2 days before the experiment). Frusemide significantly reduced the ΔPplmaxbeginning 15 mins after drug administration. This effect persisted for 5 h. The reduction in ΔPplmaxwas due partly to an increase in dynamic compliance and partly to a decrease in pulmonary resistance. Tidal volume and respiratory frequency were unaffected by frusemide. Vehicle had no effect on lung function. Flunixin meglumine abolished the effect of frusemide on airway calibre but did not prevent diuresis. These results indicate that the effect of frusemide on airways of horses with heaves persists for at least 5 h, is mediated through prostanoids, and is not a result of diuresis.
Factors influencing the outcome of equine anaesthesia: a review of 1,314 cases
Authors: YOUNG S. S. , TAYLOR POLLY M.
Published: April 2010

Patient data, physiological variables and recovery quality were extracted from 1,314 records of equine anaesthetics covering a 7‐year period and analysed retrospectively. Better recovery quality was significantly associated with shorter duration of anaesthesia, longer recovery times, less invasive surgery, a lower pulse rate at induction and higher pulse and respiratory rates during anaesthesia. Nineteen animals suffered serious anaesthetic‐related problems (1.4% incidence) and 9 died (0.68% incidence). Clinical treatment of hypotension during anaesthesia significantly reduced the hypotensive index but did not significantly alter the recovery quality or incidence of post‐anaesthetic myopathy. The severity of the myopathy was, however, markedly reduced in the animals treated for hypotension.
Administration of a receptor antagonist for platelet‐activating factor during equine endotoxaemia
Authors: CARRICK JOAN B. , MORRIS DEBRA DEEM , MOORE JAMES N.
Published: April 2010

Platelet‐activating factor (PAF) is an important mediator of endotoxaemia and various PAF receptor antagonists prevent many of the adverse effects of experimental endotoxaemia in laboratory animals. In this study a specific PAF receptor antagonist was used to investigate the role of PAF in equine endotoxaemia. At an interval of not greater than 10 days, 6 horses were each challenged with endotoxin and endotoxin with concurrent administration of SRI 63–441, a PAF receptor antagonist. The order of the treatments was randomised. Clinical signs, serum biochemical and coagulation profiles, and platelet aggregationin vitrowere monitored in all horses for 24 h after treatment. Challenge with endotoxin increased maximal platelet aggregation induced by PAF. This response was blocked by administration of SRI 63–441 concurrently with endotoxin. No changes in percentage maximal platelet aggregation to ADP or collagen were noted after administration of endotoxin. The PAF receptor antagonist delayed the onset of fever, tachycardia, leucopenia and lactic acidaemia. Lack of more profound beneficial alterations of the horses' responses to endotoxin may have been due to the low dose of endotoxin administered in this model or to only partial effectiveness of SRI 63–441 in blocking the effects of endotoxin‐induced PAF.
Racing performance of Standardbreds after conservative and surgical treatment for tarsocrural osteochondrosis
Authors: LAWS ELIZABETH G. , RICHARDSON D. W. , ROSS M. W. , MOYER W.
Published: April 2010

A retrospective study of 114 Standardbred horses diagnosed with osteochondrosis (OC) of the cranial intermediate ridge of the distal tibia was carried out, and their subsequent race records were compared with 456 control horses. Each OC‐affected horse was compared with 4 horses randomly selected from a list of horses matched to it by year of birth, sex and sire. The horses with OC were treated by arthroscopic removal of osteochondral fragments (N = 58) or managed conservatively (N = 56). The clinical presentation of these two groups was similar, although joint effusion was a more common presenting sign in the group that received surgical treatment. There was no association between presence of lameness and the type of treatment used. Data from the race records of treated and control horses (including the number of starts, lifetime earnings and record racing times) were compared. Overall, horses treated for OC had significantly fewer starts than, but earnings similar to, those in the control group. However, when stratification by sex was performed, females with OC made fewer starts and had lower earnings than did their control group. There was no significant difference in record time between OC‐affected horses and controls. These results indicate that horses treated for osteochondrosis of the cranial intermediate ridge of the distal tibia performed as well as matched controls.
Assessment and treatment of equine humeral fractures: retrospective study of 54 cases (1972–1990)
Authors: CARTER B. G. , SCHNEIDER R. K. , HARDY JOANNE , BRAMLAGE L. R. , BERTONE ALICIA L.
Published: April 2010

Fractures of the humerus were diagnosed in horses at The Ohio State University Veterinary Teaching Hospital. Twenty‐four horses (44.4%) were destroyed after radiographic assessment (mean age of 5.0 years). Surgical treatment was elected in 13 horses (24.1%, mean age of 0.42 years). Conservative management, consisting of prolonged stall rest, was chosen for 17 horses (31.5%, mean age of 2.2 years). In the surgically treated group, 3 foals (23.1%) all less than 2 months of age at the time of fracture and treated with intramedullary stack pinning, survived and became athletically sound. After conservative treatment, 9 (52.9%) horses were considered successful, 4 becoming athletically sound and 5 becoming pasture sound. The mean age at the time of presentation in the 9 horses considered successful was 1.81 years. With current fixation techniques, conservative management of equine humeral fractures appears to be as good an option as surgical treatment.
A prospective study of septicaemia in colostrum‐deprived foals
Authors: ROBINSON JULIE A. , ALLEN G. K. , GREEN ELEANOR M. , FALES W. H. , LOCH W. E. , WILKERSON CHRISTINA G.
Published: April 2010

Fourteen mares and their foals were attended at parturition. After mare‐foal bonding, 8 colostrum‐deprived (CD) foals were removed from their dams, deprived of colostrum, and provided with an alternative milk source for the first 24 h of life. The mares were milked out every 2–4 h during this period to remove colostrum, after which the CD foals were returned to their mares and allowed to nurse. Six colostrum‐fed (CF) foals were allowed to suck colostrum in the normal manner. Foal serum IgG concentration was determined by single radial immunodiffusion (means, CD = 0 mg/dl; CF = 1,508 mg/dl). Accepted methods were used to minimise infections in the neonatal foals. Of the 8 CD foals, 7 demonstrated clinical signs of sepsis. Septicaemia was confirmed in 5 of the 7 septicaemic CD foals by ante‐mortem blood culture or by culture of tissue at necropsy. Organisms isolated included:Actinobacillus equuli, Escherichia coli, undifferentiated coliforms,Pseudomonasspp., andActinomyces pyogenes. Clinically ill foals were treated with antimicrobial drugs, intravenous fluid therapy, flunixin meglumine, and anti‐endotoxin hyperimmune serum. Three septicaemic CD foals survived. Four of 7 septicaemic CD foals died or were destroyed. Post‐mortem lesions included bacterial embolic pneumonia, glomerulonephritis/nephritis, lymphoid depletion/atrophy, splenic and lymphoid necrosis, hepatitis, septic arthritis, and systemic bacterial embolism. None of the CF foals bècame septicaemic. One CF foal had foal heat diarrhoea and 1 CF foal had a serum IgG concentration of 160 mg/dl (i.e. failure of passive transfer), but both foals were otherwise normal. Despite the precautions taken to prevent infection in these foals, the severity, rapidity of disease onset, and extent of this outbreak of septicaemia in CD foals demonstrate the importance of colostral immunity in protecting neonatal foals from opportunistic and pathogenic bacterial infection.
Are tapeworms associated with equine colic? A case control study
Authors: PROUDMAN C. J. , EDWARDS G. B.
Published: April 2010

Faeces samples from 116 horses with colic and 115 non‐colic cases were assayed by a centrifugation/floatation method for the presence of tapeworm eggs. Analysis of these data failed to demonstrate an association between tapeworm infection and colic of all types. The data were further analysed according to anatomical site of the lesion causing colic. The risk of ileocaecal colic was increased in the presence of tapeworms. Age, breed and sex were evaluated as possible confounding factors but had no association with the incidence of colic. This study suggests an association between tapeworms and colic of ileocaecal origin.
Plasma constituents during incremental treadmill exercise in intact and splenectomised horses
Authors: McKEEVER K. H. , HINCHCLIFF K. W. , REED S. M. , ROBERTSON J. T.
Published: April 2010

Six intact and 6 splenectomised mares were given an incremental exercise test on a treadmill to examine the fluid and electrolyte changes associated with exercise and the role of the spleen in these changes. Blood samples were obtained at rest and at the end of each 1‐min step of the test. Exercise at 7 m/sec caused significant (P<0.05) increases in plasma osmolality (intact, +9.9%; splenectomised, +6.2%), plasma protein concentration (intact, +15.8%; splenectomised, +11.4%), and plasma K+concentration (intact 46%; splenectomised, +57%). Plasma Na+concentration did not increase significantly (P>0.05) in either group (intact =2.7%; splenectomised, =3.5%).

This appears to be the first record of substantial changes of these constituents during short‐term exercise, even before the onset of visible sweat losses. The changes in the concentration of plasma protein suggest that short‐term exercise causes a decrease in plasma volume. The changes in the concentration and content of sodium suggest that this is an isotonic shift of fluid. The increase in plasma potassium concentration appears to be due to haemoconcentration as well as an increase in the content of potassium within the vascular compartment.
Evaluation of intradermal mould antigen testing in the diagnosis of equine chronic obstructive pulmonary disease
Authors: McGORUM B. C. , DIXON P. M. , HALLIWELL R. E. W.
Published: April 2010

Intradermal end‐point titres for commercial aqueous extracts of Micropolyspora faeni, Thermoactinomyces vulgaris and Aspergillus fumigatus were determined in control and chronic obstructive pulmonary disease (COPD) affected horses. The intradermal end‐point titres of control and COPD‐affected horses were not significantly different and values for individual horses for M. faeni, A. fumigatus and T. vulgaris were not correlated with the pulmonary dysfunction or with the bronchoalveolar lavage fluid neutrophilia which had been induced by previous inhalation challenges with these antigens and by 'natural (hay and straw) challenges'.

These findings suggest divergence of the dermal and pulmonary reactivities to M. faeni, A. fumigatus and T. vulgaris in the horse and indicate that intradermal mould antigen testing is of limited value in the investigation of equine COPD.
Radiographic and microscopic correlation of diffuse interstitial and bronchointerstitial pulmonary patterns in the caudodorsal lung of adult Thoroughbred horses in race training
Authors: WISNER E. R. , O'BRIEN T. R. , LAKRITZ J. , PASCOE J. R. , WILSON D. W. , TYLER W. S.
Published: April 2010

Complete thoracic radiographic examinations were performed on 7 horses ranging in age from 24 to 60 months, followed by in‐situ lung fixation. Radiographs were examined by 3 radiologists for the presence, degree and distribution of generalised pulmonary patterns within a region of interest in the caudodorsal lung. Pulmonary tissue was obtained from 12 sites within a designated volume of interest in the caudodorsal lung, corresponding to the area of interest evaluated radiographically, and examined for the presence, character and severity of microscopic lesions. Radiographic findings within the volume of interest consisted of mild to moderate bronchial, bronchointerstitial, or interstitial pulmonary patterns. Interstitial and bronchointerstitial radiographic findings were related to severity of peribronchiolar mononuclear cell infiltrates, the degree of bronchiolar mucosal plication, and alveolar capillary and peribronchial blood vessel erythrocyte content. The severity of the interstitial radiographic pattern was inversely associated with the perceived diagnostic quality of the radiographic examinations. There was no evidence of spatial variation in the severity of the microscopic changes examined in this limited pulmonary region. Inter‐rater reliability between radiologists was good in the assessment of diagnostic quality of the radiographic examinations but poor in assessing severity of the primary generalised pulmonary patterns within the radiographic region of interest.
Streptococci andPasteurellaspp. associated with disease of the equine lower respiratory tract
Authors: WOOD J. L. N. , BURRELL M. H. , ROBERTS C. A. , CHANTER N. , SHAW Y.
Published: April 2010

The likelihood of finding evidence of inflammation in 551 tracheal washes collected endoscopically from 278 Thoroughbred racehorses increased with the number of bacterial colony forming units (cfu) per ml of wash (P<0.00l). The aerobic bacteriaStreptococcus zooepidemicus, Pasteurella/Actinobacillus‐like species andStreptococcus pneumoniaewere significantly associated with lower airway inflammation whereas coagulase‐negativeStaphylococcusspp., α‐haemolyticStreptococcusspp.,Acinetobacterspp.,Bacillusspp.,Escherichia coli, Pseudomonas aeruginosa, non‐haemolyticStreptococcusspp. and Enterobacteriaceae were not;Bordetella bronchisepticawas not isolated. Lower airway inflammation was particularly associated with bacteria in horses ≤3 years of age.S. zooepidemicus, S. pneumoniaeandPasteurella/Actinobacillus‐like species were isolated from 167 of 551 washes, either alone or in combination.
Radiographic evaluation of ossification of the collateral cartilages of the third phalanx in Finnhorses
Authors: RUOHONIEMI MIRJA , TULAMO RIITTA‐MARI , HACKZELL MINNA
Published: April 2010

Of 462 Finnhorses (age 1–20 years) evaluated and graded (scale 0–5) radiographically for ossification of the collateral cartilages of the 3rd phalanx of the front feet, 22.9% were totally free from sidebones (Grade 0), and 49.1% had minimal or mild ossification (Grade 1 or 2) at the base of 1 or more of the cartilages. Moderate ossification (Grade 3) was present in 10.2% of the horses, whereas ossification was advanced (Grade 4) or extensive (Grade 5) in 17.8%. In most horses >1 cartilage was affected and 7.6% of the horses had separate centres of ossification in 1 or more of the cartilages. Large sidebones and separate centres of ossification were more common in females than in males (P<0.001). The incidence of large sidebones was lower in young females (1–3 years) than in mares 4–6 years of age (P<0.05), but did not increase significantly with age when young horses, 4–6 years of age, were compared with older ones. Grade 4 and 5 sidebones as well as separate centres of ossification were more common in the lateral than in the medial cartilage (P<0.001), but no difference was observed in this respect between the front feet.
A study of 118 cases of navicular disease: treatment by navicular suspensory desmotomy
Authors: WRIGHT I. M.
Published: April 2010

The 118 horses diagnosed as suffering from navicular disease by prospective criteria were treated by desmotomy of the ligamenta sesamoidea collateralia (navicular suspensory desmotomy). Three techniques were used and a standard post‐operative programme was followed with clinical and radiological evaluations at 6‐monthly intervals for periods of 6–36 months after surgery. At 6 and 36 months after treatment, 76% and 42.9% of horses were sound respectively.

The clinical features of age, period of lameness, severity of lameness and angular limb deformities adversely affected response to surgery. The presence of flexor cortex defects, proximal border enthesophytes, mineralisation of the flexor digitorum profundus tendon and medullary sclerosis were also associated with a diminished response.

There were few (1.7%) changes in the radiological appearance of distal border synovial invaginations during the follow‐up period. By contrast, the majority (67.3%) of flexor cortex defects changed. Other radiological features changed at a low frequency but there was no association between radiological change and clinical outcome.
Muscular pathology in equine laryngeal neuropathy
Authors: LOPEZ‐PLANA C. , SAUTET J. Y. , RUBERTE J.
Published: April 2010

Three adductor muscles of the larynx, the cricoarytenoideus lateralis (CAL), the arytenoideus transversus (AT) and the ventricularis (Ve), from 36 horses were examined histologically. The neurogenic changes seen in each muscle were evaluated qualitatively. In addition, in 6 horses with clinical and subclinical signs of neurogenic atrophy, measurements of muscle fibre area were performed. Neurogenic changes observed in the Ve were less than in CAL and AT. Measurements of muscle fibre area also demonstrated that CAL and AT showed a wider range of pathological changes than did Ve. The results show that denervation does not uniformly affect all adductor muscles of the larynx. On the other hand, the appearance in some animals of fibre type grouping in the right AT to the same or to a greater extent than in the left AT supports the classification of equine laryngeal neuropathy as a distal axonopathy.
Review of 115 cases of colic in the pregnant mare
Authors: BOENING K. J. , LEENDERTSE IDA P.
Published: April 2010

The medical records of pregnant mares over a 3‐year period were reviewed. In all cases persistent pain or progressive abdominal distension were the main reason for referral.

The overall survival rate for the 115 mares treated for colic was 73.9% (85 cases). The abortion rate was 20.5% in surgical patients (34 cases), 40% (5 cases) for mares with uterine torsions and 10.8% (46 cases) after medical treatment. The total abortion rate was 16.4%.

Clinical evidence of endotoxaemia was, except for 1 mare, present in all the aborting mares after colic treatment. Anaesthesia did not appear to be a problem because abortion occurred in 5/46 medically treated cases as well as in 9/39 mares treated surgically. Abortion occurred in 3 mares that suffered intraoperative hypoxia, but fasting for >30 h did not seem to cause prolonged hypoglycaemia and subsequent abortion. Clenbuterol hydrochloride was used as a tocolytic agent in 9 mares with uterine displacement, abortus imminens and post‐operative uterine torsion and 3 mares aborted during treatment.
In vitro mechanical properties of the accessory ligament of the deep digital flexor tendon in horses in relation to age
Authors: BECKER CHRISTINA K. , SAVELBERG H. H. C. M. , BARNEVELD A.
Published: April 2010

The material properties of the accessesory ligament of the deep digital flexor tendon (AL) of 21 forelimbs from horses between ages one day and 15 years were determined. The force (634–11416 N), failure stress (45–138 N/mm2), failure strain (7–24%) and tangent modulus (33–1639 MPa) are presented in relation to age. Tangent modulus did not indicate changes in elasticity due to age. The results demonstrate that complete ligament failures (CLF) of ALs of older horses (mean 7835 N) occur at lower forces than ALs of young adult horses (mean 8894 N). Sudden decreases, ‘dips’, in the force‐time curves were noticed in ligaments from foals and yearlings and in ligaments from horses >10 years. They were interpreted as the failure of a number of fibres which either fail at lower forces or are subject to higher forces than the rest. These differences in mechanical properties could be the result of age related differences in the material properties of ALs of older horses similar to alterations in collagenous tissue in other species. When analysing the data of the proximal, middle and distal regions of the ligaments separately, higher strain and elasticity were found in the distal compared to the proximal parts.

It is suggested that the clinical occurrence of desmitis of the AL of older horses could be due to fibrillar failure caused by differences in the material properties of the ligaments.
Pulmonary vascular pressures of Thoroughbreds increase rapidly and to a higher level with rapid onset of high‐intensity exercise than slow onset
Authors: MANOHAR M.
Published: April 2010

Previous studies of pulmonary vascular pressures have utilised gradual incremental step exercise protocols, but in competitive racing at the track, horses perform rapid acceleration high‐intensity exercise. The rate of rise in pulmonary vascular pressures under conditions of quick onset high‐intensity exercise is unknown. Catheter mounted manometers, whosein vivosignals were matched with pressure signals obtained via transducers connected to fluid‐filled lumens from same cardiovascular sites, were used to compare right heart and pulmonary vascular pressures in 8 healthy Thoroughbreds performing 2 separate exercise protocols on a high speed treadmill (gradually incremental vs. rapid acceleration exercise protocol where the belt speed was raised from 8 m/s to 15 m/s in 8 s). Heart rate, right atrial and pulmonary vascular pressures at rest were similar for the 2 protocols. Rapid acceleration of horses from 8 to 15 m/s was attended by an equally rapid escalation in the right heart and pulmonary vascular pressures such that these pressures reached their zenith as belt speed approached 15 m/s. Although exercise at 15 m/s resulted in similar heart rate in the 2 protocols, the mean ± s.e. values of mean right atrial pressure, mean pulmonary artery pressure, mean pulmonary artery wedge pressure and mean pulmonary capillary pressure (91.5 ± 3.9 mmHg) in the rapid acceleration exercise were significantly (P<0.05) higher than respective values at 15 m/s in the gradual incremental step exercise protocol. It is concluded that pulmonary capillary blood pressure of Thoroughbreds rapidly accelerating to high‐intensity exercise increases just as rapidly as their speed and that the values achieved are higher than in incremental step exercise protocol; thereby playing a potential role in initiating stress failure of pulmonary capillaries and exercise‐induced pulmonary haemorrhage very early in a race.
An algorithm to describe the oxygen equilibrium curve for the Thoroughbred racehorse
Authors: SMALE K. , ANDERSON L. S. , BUTLER P. J.
Published: April 2010

An algorithm to describe the oxygen equilibrium curve (OEC) of the Thoroughbred horse was derived from raw oxygen equilibrium curve data obtained under standard conditions of temperature, pH and PCO2 (Smale and Butler, 1994). This algorithm was derived by a curve‐fitting procedure based on the algorithm for human blood produced by Kelman (1966). The temperature, fixed acid and net CO2 coefficients were then incorporated in the algorithm to enable the accurate calculation of % saturation from any combination of PO2, temperature, pH and PCO2. The algorithm was checked using blood gas data obtained from in vivo treadmill exercise tests as well as a standardised breathing test whereby horses inhaled several different gas mixtures. This algorithm proved more accurate for the Thoroughbred horse than that derived by Kelman.
Susceptibility of ponies to infection with Streptococcus pneumoniae (capsular type 3)
Authors: BLUNDEN A. S. , HANNANT D. , LIVESAY G. , MUMFORD JENNY A.
Published: April 2010

Welsh Mountain ponies were inoculated with an isolate of Streptococcus pneumoniae, SPE 1618 (capsular type 3) recovered from the equine respiratory tract: 10 ml of a suspension of 108 or 109 cfu/ml were instilled intratracheally. Fever was observed after either dose but the greater concentration also produced coughing, ocular and nasal discharge, depression and enlargement of submandibular lymph nodes. Cytological evidence of infection was also observed in tracheal washings during the first week after inoculation and corresponded with isolation of S. pneumoniae from the washes. Morbid anatomical and histopathological examinations of selected animals revealed focal pneumonia affecting the ventral lung, especially the cardiac area and accessory lobe, with a propensity to affect the right lung. S. pneumoniae was isolated directly in pure culture from these lesions or was demonstrable by immunostaining of macrophages bearing specific capsular type 3 antigen. By 10 days after inoculation, the ponies were healthy and had developed antibodies to S. pneumoniae. S. pneumoniae was therefore a primary pathogen in the horse under the conditions of the challenge.
Ultrasonographic assessment of the proximal digital annular ligament in the equine forelimb
Authors: DIK K. J. , BOROFFKA S. , STOLK P.
Published: April 2010

Ultrasonography was used with 6 normal cadaver forelimbs of Dutch Warmblood horses to delineate the ultrasonographic anatomy of the palmar pastern region, with emphasis on the proximal digital annular ligament. Using a 5.5 MHz sector scanner, the thin proximal digital annular ligament was not visible on offset sonograms. Only if the digital sheath in the normal limb was distended was the distal border of this ligament outlined. In all normal limbs the palmarodistal thickness of the combined skin‐proximal digital annular ligament layer in the mid‐pastern region was 2 mm. The flexor tendons and distal sesamoidean ligaments were easily identified as hyperechoic structures. Distension of the digital sheath in the normal limbs clearly outlined the anechoic digital sheath pouches. In 4 lame horses ultrasonography aided the diagnosis of functional proximal digital annular ligament constriction. In all 4 diseased forelimbs ultrasonography demonstrated thickening of the skin‐proximal digital annular ligament layer and distension of the digital sheath. In one of these limbs the distended digital sheath was also thickened. The flexor tendons and distal sesamoidean ligaments were normal. There was no radiographic evidence of additional bone or joint lesions.
Transendoscopic electrocautery‐induced gastric ulcers as a model for gastric healing studies in ponies
Authors: MacALLISTER C. G. , LOWREY F. , STEBBINS M. , NEWMAN MARTHA S. , YOUNG BAMBI
Published: April 2010

The ponies were apparently healthy and 6–20 months of age. In Study 1, gastric lesions were created by transendoscopic electrocautery in the non‐glandular gastric mucosa, adjacent to the margo plicatus in 9 ponies which were then treated with water, 12 mg Cimetidine HCl/kg bwt or 18 mg Cimetidine HCl/kg bwtper osevery 12 h for 35 days. In Study 2, gastric lesions were similarly induced in 9 ponies in the non‐glandular mucosa and also in the glandular mucosa just below the non‐glandular lesion on the greater curvature of the stomach. The ponies were treated with water, 8 mg cimetidine/kg bwt or 16 mg cimetidine/kg bwtper osevery 8 h for 21 days. In both studies gastric lesion healing was monitored twice weekly by video gastroscopy. There was no apparent difference in healing times between the water and Cimetidine treatment groups in either study.

These results indicate that uniform gastric ulcers can be created by transendoscopic electrocautery in the non‐glandular mucosa of ponies and that these ulcers heal at a predictable rate which should be useful in studying compounds that might accelerate healing of gastric mucosal lesions. However, Cimetidine was not effective in accelerating the rate of healing under the conditions of this study.
Serological and microbiological findings on 3 farms with equine leptospiral abortions
Authors: WILLIAMS DEBORAH M. , SMITH B. J. , DONAHUE J. M. , POONACHA K. B.
Published: April 2010

Blood and urine samples from horses on 3 central Kentucky horse farms with prior histories of leptospiral abortions were analysed. Blood samples were obtained from all available horses on each farm and tested for antibodies to 6 leptospira serovars. Urine samples were collected from non‐gravid mares with serum antibody titres ≥1:800 and examined for leptospires by dark‐field microscopy, fluorescent antibody testing and culture. Adult horses had the greatest serological evidence of exposure to leptospira, followed by yearlings, then foals. Of horses with anti‐leptospiral antibodies, 76.3% reacted against serovarbratislava, 49.1% againsticterohaemorrhagiae, 20.1% againstgrippotyphosa, 16.3% againstpomonagenotypekennewicki, 15.9% againsthardjoand 1.0% againstcanicola.These findings confirmed that horses in central Kentucky are exposed to multiple leptospira serovars. The seroprevalence of antibodies to the 6 selected serovars was consistent among the 3 selected farms. There was no direct correlation between the serovar that was the cause of abortion in the previous season and prevalence of positive titres to that serovar in horses tested on the farms in the following year. Furthermore, there was no evidence of long‐term urinary shedding of leptospira by horses with high leptospira antibody titres.
Evaluation of pulse oximetry in horses surgically treated for colic
Authors: MATTHEWS NORA S. , HARTSFIELD SANDEE M. , SANDERS ELIZABETH A. , LIGHT GWENDOLYN S. , SLATER MARGARET S.
Published: April 2010

All 43 horses anaesthetised for colic surgery were premedicated with xylazine or diazepam. Anaesthesia was induced with guaifenesin and ketamine, horses were placed in dorsal recumbency and anaesthesia was maintained with isoflurane in oxygen and mechanical ventilation. Haemoglobin saturation readings (Spo2) were taken with a pulse oximeter and compared with computed haemoglobin saturation (Spo2) from arterial blood samples. Readings were taken over a range ofSpo2of 78–100%, mean arterial blood pressure ranged from 24 to 108 mmHg andPao2ranged from 53 to 490 mmHg.

Analysis of 107 readings showed thatSpo2values predictedSpo2but time, blood pressure and individual horse did not. Correlation coefficients betweenSpo2andSpo2were 0.85 for all values and 0.88 for values at 30 min. Values for bias and precision were calculated for allSpo2values and for readings separated into 3 saturation groups: normal, low normal, and abnormal. The pulse oximeter tended to underestimateSpo2at all times, and was less precise as the saturation decreased.
Investigation of association between alpha‐1 proteinase inhibitor haplotype and endometritis in the Thoroughbred mare
Authors: PEMBERTON A. D. , JOHN H. A. , RICKETTS S. W. , ROSSDALE P. D. , SCOTT A. M.
Published: April 2010

Failure to inhibit proteinases can lead to excessive tissue damage. The possibility that the severity of endometritis in Thoroughbred mares correlates with the haplotypes of plasma α1‐proteinase inhibitor (α1‐PI) expressed was investigated in two groups of mares. In mares with pyometritis before treatment, the frequency of the N haplotype, which is already high in the Thoroughbred population, was significantly increased when compared with that in a large published population. In mares with acute endometritis which persisted after treatment followed by sexual rest, the absence of S and T haplotypes was significant, suggesting that, when present, they may have a protective function.
The prevalence of latent Equid herpesviruses in the tissues of 40 abattoir horses
Authors: EDINGTON N. , WELCH H.M. , GRIFFITHS L.
Published: April 2010

Equid herpesviruses 1 or 4 (EHV‐1 or −4) were isolated by co‐cultivation from 60% of 40 horses examined at slaughter. The lymph nodes draining the respiratory tract were the most common source of virus. EHV‐1 or EHV‐4 was never isolated from the trigeminal ganglia (SLG). The polymerase chain reaction (PCR) detected virus in 87.5% of bronchial lymph nodes and a similar level in the trigeminal ganglia that were examined. By both assays approximately one third of the positive animals harboured both viruses.

Equid herpesvirus 2 (EHV‐2) was isolated from all but one of the horses and from >75% of the lymph nodes draining the respiratory tract; a viruses were isolated only in the presence of EHV‐2.

The results indicate that latent EHV‐1 and EHV‐4 are widespread in the equine population and that the primary site of latency is the lymph nodes of the respiratory tract.
Progression and association with lameness and racing performance of radiographic changes in the proximal sesamoid bones of young Standardbred trotters
Authors: GRØNDAHL A. M. , GAUSTAD G. , ENGELAND A.
Published: April 2010

Radiographic examination of the metacarpo‐ and metatarsophalangeal joints was performed on 753 Standardbred trotters (6–21 months of age): 21 showed obvious changes in 26 proximal sesamoid bones on lateromedial projection. The radiographic changes were divided into 6 different types: (1) irregular abaxial margin (8 horses); (2) enlargement of the sesamoid bone (6 horses); (3) ‘fracture’ or separate centre of ossification of the apex (4 horses); (4) vertical, non‐articular fracture of the plantar part of the sesamoid bone (1 horse); (5) a small bony fragment located in a defect in the apical part of the bone (2 horses); and (6) multiple areas of decreased radiodensity (1 horse). Each horse displayed only one type of radiographic change except for one which possessed those of types 3 and 5. Follow‐up radiographic examination of 21 of the 26 affected proximal sesamoid bones at ˜6‐month intervals revealed a reduction in the changes in 13 bones and an unaltered condition in 8. Lameness examination was performed on 16 of the 21 horses at 3 years of age and 14 (87.5%) were observed to be lame, but detected lameness did not seem to be referrable to the sesamoid changes. Earnings after the racing season as 3‐ and 4‐year‐old horses showed no differences (P>0.05) between horses with radiographic changes in the proximal sesamoid bones and those without such changes.
Effects of centrifugation and specimen preparation technique on bronchoalveolar lavage analysis in horses
Authors: LAPOINTE J.‐M. , VRINS A. , LAVOIE J.‐P.
Published: April 2010

Bronchoalveolar lavages (BAL) were performed for 6 healthy horses and 8 horses with lower airway diseases (LAD). Total cell and differential counts were performed before and after centrifugation and resuspension of the BAL cells in a small volume of fluid; there was no difference in the total cell counts, but mast cell percentages were significantly (P<0.05) lower, after centrifugation, in the LAD group. The two specimen preparation techniques compared were cytocentrifugation and centrifugation on microscope glass covers. For both groups of horses, lymphocyte percentages were significantly lower on cytocentrifuged specimens; there was also an increase in the other predominant cell type, i.e. macrophages in healthy horses and neutrophils in horses with LAD. Lymphocyte percentages in healthy horses were higher than those reported in previous studies, possibly because of a long‐standing exposure to a high‐dust environment. This study suggests that one centrifugation of the BAL fluid does not affect total cell counts, but may cause a decrease in mast cell percentage; cytocentrifugation is associated with a consistent decrease in lymphocyte percentage.