bluuebunny/crossref_metadata_2025 huggingface dataset:
Equine motor neuron disease: findings in 28 horses and proposal of a pathophysiological mechanism for the disease
Authors: DIVERS T. J. , MOHAMMED H. O. , CUMMINGS J. F. , VALENTINE B. A. , DE LAHUNTA A. , JACKSON C. A. , SUMMERS B. A.
Published: April 2010

Over a three and one‐half year period, 28 adult horses were diagnosed with equine motor neuron disease (EMND). The most commonly identified environmental risk factors for a horse having EMND were absence of grazing for more than a year and provision of poor quality hay. Quarter Horses were 5.4 times more at risk than other breeds but this was thought to be an epiphenomenon related to the frequency of Quarter Horses at boarding stables.

Weight loss, excessive recumbency and/or trembling were the first signs noted. Other clinical diagnostic signs included: constant shifting of the weight in the rear limbs, abnormally low head carriage and muscle fasciculations. Excellent to ravenous appetites were present in all cases and marked coprophagia in some cases.

Abnormally high serum concentration of muscle‐derived enzymes was the only consistent serum chemistry abnormality found. Abnormal glucose absorption, increased cerebrospinal fluid total protein and intrathecal production of IgG were identified in a number of cases.

Euthanasia was performed on 5 horses within 4 days of hospital admission, because of inability to stand or respiratory distress, and on 18 horses after the diagnosis had been completed. Five affected horses were maintained for observational purposes for periods of 9 months to over 2 years after the onset of clinical signs. They were given access to pasture and 2 were given supplemental vitamin E as the only therapy. Marked clinical improvement occurred in the 4 more acutely affected horses.

Pathological findings, preference of type 1 muscle fibre atrophy and lipopigment accumulation within the capillary endothelium of the spinal cord of all cases, supported the hypothesis of EMND being an oxidative disease. In addition, after the absence of pasture was identified as a possible risk factor, plasma vitamin E was measured in the last 10 cases and was found to be significantly (P = .0028) lower than controls. It was hypothesised that in EMND, motor neurons with the highest oxidative activity are made susceptible to an oxidative insult by a deficiency in dietary antioxidants and if enough motor neurons are diseased, clinical signs of EMND occur. The stabilisation of clinical signs in 9 cases and the marked improvement in 4 horses suggest that, if an oxidative insult(s) is responsible for initiating the motor neuron disease, its effect is not progressive in many cases.
Absorption and dosage of theophylline in the horse after single and repeated administration of a microencapsulated preparation
Authors: RONCADA P. , TOMASI L. , MONTESISSA C. , GROSSI G. , STRACCIARI G. L. , ANFOSSl P.
Published: April 2010

The kinetics of 2 formulations of theophylline were studied in horses. In an initial cross‐over study (Phase I) serum concentration‐time curves were determined for granulated and microencapsulated theophylline after a single oral administration (5 mg/kg bwt). In Phase II microencapsulated theophylline was administered at 5 mg/kg bwt/12 h for 10 days at feeding time, as in normal clinical practice. Although no significant differences between the 2 preparations were found with respect to the main kinetic parameters, the microencapsulated form was more evenly and completely absorbed from the digestive tract; furthermore, after the repeated treatment, its trough‐peak serum concentrations were always within the therapeutic window and no toxic effects were observed in treated animals.
How the horse moves: 1. Significance of graphical representations of equine forelimb kinematics
Authors: BACK W. , SCHAMHARDT H. C. , SAVELBERG H. H. C. M. , VAN DEN BOGERT A. J. , BRUIN G. , HARTMAN W. , BARNEVELD A.
Published: April 2010

The kinematics of 24 two‐year‐old Dutch Warmblood horses were recorded at the trot (4 m/s) on a high‐speed treadmill to study the coordination of joints within the equine forelimb. Joint angle‐time, angle‐angle, stick, and marker diagrams were used to show forelimb motion graphically. Because the kinematic data referred to the joint angles of the horse standing squarely and were time‐standardised to the duration of the stride cycle, mean joint curves could be calculated for the total group. The motion of each segment in the equine forelimb during a complete stride is described and its function in intralimb coordination evaluated. It appeared that the rotation of the scapula and the cranio‐caudal movement of the distal forelimb are synchronous and pendular. The carpal joint rapidly snaps into overextension at the beginning of the stance phase to enable the forelimb to work as a propulsive strut. The fetlock joint acts as an elastic spring, thereby conserving energy and, at the same time, absorbs oscillations generated by initial ground contact. Furthermore, the coordination between carpal and fetlock joints in the swing phase appears to be strongly influenced by inertia. Using the graphic tools evaluated in this paper, we were able to visualise the kinematics of the equine forelimb and relate these to specific functions of the forelimb in locomotion. This information can be used to select kinematic variables for clinical studies in which equine forelimb function has to be described and quantified.
Sensory innervation of the navicular bone and bursa in the foal
Authors: BOWKER R. M. , UNDER K. , SONEA I. M. , HOLLAND R. E.
Published: April 2010

The sensory innervation of the navicular bone (os sesamoideum distale) and its suspensory ligaments [ligamenta sesamoidea collateralia (CSL) and ligamentum sesamoideum distale impar or distal sesamoidean impar (DS‐impar) ligament] and the navicular bursa (podotrochlearis) was examined in the neonatal foal using immunocytochemistry. With antisera raised to substance P (SP) and human calcitonin gene‐related peptide (CGRP), immunoreactive nerves were demonstrated to innervate the CSL and navicular bursa. Within CSL, the SP‐ and CGRP‐like nerves were present in the synovial lining of the navicular bursa, appearing to reach the surface lining. These nerves appeared to enter the CSL and navicular bursa via the abaxial regions of the foot. Both peptides were present in the deep digital flexor tendon (DDf) along the palmar border of the navicular bursa, as well as in the DS‐impar ligament. More nerve fibres were present in the dorsal part of CSL bordering the distal interphalangeal joint than was observed palmarly in CSL along the navicular bursa. Both peptides were observed to innervate the cartilage canals within the navicular bone. In terms of relative densities of immunoreactive SP‐ and CGRP‐like peptides, the CSL dorsally and the DS‐impar ligament had the highest relative densities of nerve fibres followed by the navicular bone, the palmar aspect of CSL and the DDf tendon bordering the navicular bursa. These results are discussed in relationship to local anaesthetic injections into the navicular bursa.
Radiographic and endoscopic study of horses performing an oral based stereotypy
Authors: MCGREEVY P. D. , RICHARDSON JILL D. , NICOL CHRISTINE J. , LANE J. G.
Published: April 2010

There is confusion in the veterinary literature concerning the definition of oral based stereotypies in the horse. This study reports the use of fluoroscopy and endoscopy during crib‐biting/wind‐sucking in afflicted horses. This permitted observations of movements of the pharyngeal and oesophageal tissues and of the air column within during the stereotypic behaviour. The findings reported show that the sequence of events during crib‐biting/wind‐sucking is not related to deglutition and that air is not swallowed to the stomach. Transient dilation of the upper oesophagus was recorded and the characteristic noise of wind‐sucking coincided with the in‐rush of air through the cricopharynx. The oesophageal distension was relieved when the air returned to the pharynx although small quantities passed caudally. It is proposed that the role of contraction of the strap muscles of the neck is to create a pressure gradient in the soft tissues surrounding the oesophagus which provokes movement of air from the pharynx into the oesophagus. The findings suggest that the definitions currently used in the sale of horses are in need of revision.
Iridium‐192 interstitial brachytherapy for equine periocular tumours: treatment results and prognostic factors in 115 horses
Authors: THÉON A. P. , PASCOE J. R.
Published: April 2010

One hundred and fifteen horses with periocular tumours were treated with iridium‐192 interstitial brachytherapy. Tumours included squamous cell carcinomas (n=52) and sarcoids (n=63). All horses were scheduled to receive 60 Gy (minimal tumour dose) given at a low dose rate (0.034 ± 0.010 Gy/h). The mean and median follow‐up times to last contact or death were 24 and 16 months, respectively. Chronic radiation reactions included palpebral fibrosis (10.4%), cataract (7.8%), keratitis and corneal ulceration (6.9%). Cosmetic changes included permanent epilation (21.7%) and hair dyspigmentation (78.3%). The one year progression‐free survival (PFS) rates for sarcoids and carcinomas were 86.6% and 81.8% and the 5 year PFS rates were 74.0% and 63.5%, respectively. The horse age and sex, histopathological type, anatomical subsite and classification (WHO T1‐3) were included in the analysis of prognostic factors. The only significant prognostic factor that independently affected PFS time was the WHO T‐classification (P=0.009, relative risk=0.85). When compared to horses with T1 lesions, horses with T2 and T3 lesions had 1.8‐fold and 3.4‐fold increased risks, respectively, for tumour recurrence (relative excess risk). The one year PFS rates for T1, T2 and T3 lesions were 95.2%, 89.5% and 66.2%, respectively. The 5 year PFS rates were 72.2%, 74.0% and 53.1%, respectively. The results of this study indicate that irradiation is an effective treatment option for horses with T1‐2 lesions and should be part of a combined treatment modality for horses with T3 lesions.
Experiences in treatment of epiglottal entrapment using a hook knifeper nasum
Authors: GREET T. R. C.
Published: April 2010

Thirty eight horses with epiglottal entrapment were examined. In 29 the dorsally displaced mucosa was split axially with a curved hook knife,per nasum. The condition was also treated by subepiglottal mucosal resection (4 horses) and solely by the administration of an anti‐inflammatory throat spray (4 horses). All surgical cases were treated with an anti‐inflammatory throat spray and parenteral phenylbutazone. Those horses treated via a laryngotomy incision were box rested until the laryngotomy incision healed. The other horses were restricted to walking and trotting exercise for 10 days before endoscopic re‐assessment. If the condition had resolved by this stage the horse was then returned to full exercise. Epiglottal entrapment was alleviated in 22 horses treated by axial section but it recurred in 4 and 3 cases were lost to follow up. Two of 4 cases were treated successfully but mucosal resection and 2 of 4 cases by Nd:YAG laser. Three out of the 4 horses treated medically also recovered. Of the 38 horses, 6 required a second operation and 2 had a third surgical procedure. Of the horses treated by axial section of the displaced mucosa, 14 ran successfully without a respiratory sound or obstruction and 4 won races.

In conclusion, using the hook knife inserted via the nasal passages offers a safe, relatively inexpensive and successful method of treating epiglottal entrapment.
Evaluation of Directigen Flu A assay for detection of influenza antigen in nasal secretions of horses
Authors: MORLEY P. S. , BOGDAN J. R. , TOWNSEND H. G. G. , HAINES DEBORAH M.
Published: April 2010

The Directigen Flu A assay (Becton Dickinson, Microbiology Systems, Mississauga, Ontario, Canada) is a commercially available immunoassay designed for rapid in vitro recognition of influenza A nucleoprotein. The purpose of this study was to evaluate this assay for detection of influenza virus in nasal secretions of naturally infected horses. The assay was shown to react with representative strains of influenza virus which cause disease in horses and did not react with nasal secretions from uninfected horses kept in isolation. Between 33% and 45% of nasal secretions specimens obtained from clinically diseased horses during influenza epidemics reacted positively in the assay and 95% to 98% of horses not showing signs of disease during influenza epidemics tested negative. In contrast, influenza virus was isolated from only 7% of diseased horses using conventional techniques. Diseased horses which were positive in the Directigen assay had lower pre‐exposure influenza antibody concentrations and showed more clinical signs than diseased Directigen‐negative horses. This evaluation demonstrates that the Directigen Flu A assay detects influenza virus in nasal secretions of infected horses and is more sensitive than virus isolation.
Histological and physical assessment of poor hoof horn quality in Lipizzaner horses and a therapeutic trial with biotin and a placebo
Authors: ZENKER W. , JOSSECK H. , GEYER H.
Published: April 2010

This paper represents the second part of a study searching for factors which could be responsible for an inferior hoof horn quality of the Lipizzaner horses of the Viennese Spanish Riding School (SRS) noticed in the late 1980s. It includes an evaluation of a treatment with biotin and 42 Lipizzaner horses were tested in a double blind study. The following parameters were evaluated: 1) the histology of the hoof horn in samples from the bearing border 2) the tensile strength of the coronary horn in bearing border samples and 3) the influence of biotin upon the histological changes and the tensile strength after application of 20 mg/day of biotin during 38 months. The histological alterations of bearing border specimens were assessed by use of a grading system (Grade 0= unchanged;Grade 1= slight changes;Grade 2= moderate changes;Grade 3= severe changes).

Initially more than two thirds of the horses showed moderate to severe changes: microcracks visible in the transition from the middle to the inner zone of the coronary horn; separation of the sole from the coronary horn in the region within the white zone. The tensile strength of the coronary horn, with a mean of 39 N/mm2, was 13 N/mm2lower compared with the unchanged hooves of 10 Warmblood horses, which were investigated by Küng (1991). After 19 months of biotin treatment, the horn quality showed a small but significant improvement. This could be shown by comparing the histological tissue structure before and after treatment, as well as treated animals vs. a placebo group. However, all hooves still showed slight or middle grade changes at the time of the last examination. In tensile strength measurements made 33 and 38 months after the beginning of the trial, the biotin treated group had improved over the placebo group.
Variations in urinary gamma glutamyl transferase/urinary creatinine ratio in horses with or without pleuropneumonia treated with gentamicin
Authors: ROSSIER Y. , DIVERS T. J. , SWEENEY R. W.
Published: April 2010

The urinary GGT/urinary creatinine (uGGT/uCR) ratio was measured on Days 1, 3 and 10 in 4 adult, healthy horses; in 6 adult, healthy horses treated with gentamicin at recommended dosages and 9 adult horses treated for pleuropneumonia with gentamicin at recommended dosages. Plasma creatinine and gentamicin trough concentrations were measured on the same days. The uGGT/uCr ratio was higher in the normal horses (mean ± s.d. 22.85 ± 13.69) than previously reported normal values (10.5 ± 6.8) (Adams and McClure 1985). Analysis of variance for repeated measures was used to compare the ratio in the 3 groups while controlling for the effect of time. Sick horses had a significantly higher uGGT/uCr ratio than either of the 2 groups of normal horses. Both groups of horses that were treated with gentamicin had similar percentage increases in uGGT/uCr ratio over the treatment period with the most marked increases found between treatment Days 1 and 3. The increase in uGGT/Cr ratio was predominantly a result of an increase in uGGT activity rather than a decrease in uCr concentration. The increase in uGGT activity and uGGT/uCr ratio occurred without abnormalities in serum creatinine or gentamicin trough concentrations. These findings demonstrate that urine GGT activity and uGGT/uCr ratio should be expected to increase in response to gentamicin therapy at recommended dosages without measurable changes in serum creatinine. This suggests that an elevation of the uGGT/uCr ratio in horses being treated with gentamicin would not necessarily require changes in, or withdrawal of, the gentamicin treatment as long as increases in the plasma creatinine do not exceed 0.3 g/l and gentamicin trough concentrations are <2 μg/l.
Tendonitis of the deep digital flexor tendon in the distal metacarpal/metatarsal region associated with tenosynovitis of the digital sheath in the horse
Authors: BARR A. R. S. , DYSON SUE J. , BARR F. J. , O'BRIEN J. K.
Published: April 2010

Twenty‐four horses with ultrasonographic evidence of tendonitis of the deep digital flexor tendon in the metacarpal/metatarsal region were seen over a 7 year period. Most horses had mild to moderate lameness and distension of the digital flexor tendon sheath in the affected limb. Intrasynovial analgesia of the digital flexor tendon sheath consistently improved the degree of lameness. Ultrasonography most commonly revealed small, distinct, often circular, focal hypoechoic areas within the deep digital flexor tendon which usually extended less than 1 cm proximodistally. The degree of lameness and swelling generally improved with box rest and controlled exercise, however, exacerbation of the clinical signs and ultrasonographic lesions was common when affected horses were returned to work or allowed free exercise at pasture. Of 24 cases, only 7 horses made a full recovery and returned to their intended athletic activity.
Comparison of polysulphated glycosaminoglycan and sodium hyaluronate with placebo in treatment of traumatic arthritis in horses
Authors: GAUSTAD GUDRUN , LARSEN S.
Published: April 2010

A randomised double blind and placebo controlled clinical study was carried out. Standardbred trotters (n=77, age 3–4 years) with moderate to severe lameness were grouped according to number of affected joints and, within each group, were randomised for treatment with polysulphated glycosaminoglycan (PSGAG), sodium hyaluronate (SH) or placebo for 3 weeks. The horses were inspected weekly with a final examination 2–4 weeks after the end of treatment.

Mean initial lameness score was significantly reduced during treatment and at the last examination in all 3 groups (P<0.01). Additionally, the prevalence of sound horses increased significantly from 1 to 3 weeks of treatment and to the last examination in all 3 groups (P≤0.03). Comparison of the 2 treatment groups with regard to development of the lameness curve and time until soundness indicated a small, non significant difference in favour of SH. No significant difference was detected between the 2 treatment groups in the prevalences or cumulative incidence of soundness. The study detected a superior effect of the 2 drugs compared with placebo for reduction in lameness score during the treatment period (P=0.03) and the total study period (P<0.01), time until soundness (P=0.04) and the prevalence of sound horses at the last examination (P<0.01). All 3 treatments affected traumatic arthritis in horses, but the SH and PSGAG gave better results Than the placebo.
Equine pulmonary disease: a case control study of 300 referred cases. Part 2: Details of animals and of historical and clinical findings
Authors: DIXON P. M. , RAILTON D. I. , McGORUM B. C.
Published: April 2010

Examination of historical and clinical details of 270 adult horses suffering from a variety of mainly chronic pulmonary diseases showed that the chronic obstructive pulmonary disease (COPD) group (median age 9 years) were the oldest, and that the COPD, chronic idiopathic hypoxaemia and exercise induced pulmonary haemorrhage (EIPH) groups had the longest duration of disease (median durations 7, 12 and 9 months, respectively) with a median disease duration of 2 months for the remaining horses. A history of antecedent respiratory infection was present in 24.3% of all horses. Six out of 12 horses that grazed with donkeys suffered lungworm infection. Silage was fed to 11.3% of all horses, nonstraw beddings were utilised by 28.7% of horses and 8.7% of horses were maintained permanently outdoors. Environmental control had been unsuccessfully attempted in 47% of COPD cases prior to referral. Histories of poor athletic performance or of excessive post exercise dyspnoea were found to be less definitive indicators of pulmonary disease. Coughing was the most sensitive clinical indicator of pulmonary disease, being present in 71.1% of horses with pulmonary disorders. Nasal discharge was present in 50.4% of these horses and coughing or nasal discharge was present in 86.7% of horses with respiratory disorders. Unilateral nasal discharge was inexplicably present in 3.3% of horses with pulmonary disease. Other clinical findings, including the presence of increased breathing effort, abnormal thoracic or tracheal auscultatory findings were less sensitive diagnostic parameters with pulmonary diseases, and were frequently absent unless severe pulmonary disease was present.
Equine pulmonary disease: a case control study of 300 referred cases. Part 4: Treatments and re‐examination findings
Authors: DIXON P. M. , RAILTON D. I. , McGORUM B. C. , TOTHILL SARAH
Published: April 2010

One‐hundred and forty‐seven of 270 (54.4%) horses suffering from pulmonary disorders were given at least one reexamination including, clinical, bronchoscopic, pulmonary function and cytological examinations after treatment and a further 83 of these horses (30.7%) had their clinical progress assessed by verbal or written reports. These examinations and progress reports showed high levels of partial or total recovery for most pulmonary disease categories, including chronic obstructive pulmonary disease, infectious, S. zooepidemicus and undifferentiated pulmonary disease and lungworm infection groups but not for the miscellaneous pulmonary disease (40% of these cases died), idiopathic chronic hypoxaemic or exercise induced pulmonary haemorrhage groups.
Protein tyrosine phosphorylation in equine platelets: the effect of stimulation by thrombin and platelet‐activating factor (PAF)
Authors: DILLON ANNE M. R. , HEATH M. F.
Published: April 2010

Protein tyrosine phosphorylation (PTP) in thrombin‐ and platelet‐activating factor (PAF)‐ stimulated equine platelet activation was investigated in the absence and presence of 2 protein tyrosine kinase inhibitors (PTKIs), methyl 2,5‐dihydroxyciimamate (MDHC) and genistein.

Washed equine platelets aggregated irreversibly in response to thrombin or PAF in an agonist concentration dependent fashion. MDHC produced an MDHC concentration and time dependent inhibitory effect on rate and extent of thrombin‐ and PAF‐ induced aggregations, whereas the effect of genistein on the same parameters was only genistein concentration dependent.

Western blotting demonstrated tyrosine phosphorylated proteins in resting platelets. Changes in the PTP pattern occurred both when platelets were stimulated with varying concentrations of thrombin or PAF for a standard time (3 min) or with a standard agonist concentration (0.17 u/ml thrombin or 10−10mol/l PAF) for varying times. Different patterns of PTP were produced by thrombin and PAF. 500 μmol/l MDHC and 300 μmol/l genistein each affected the PTP patterns produced in response to thrombin or PAF, but in different ways. PTP results with thrombin and PAF in the presence of 500 μmol/l MDHC were similar, as were those in the presence of 300 μmol/l genistein. However, there were many differences in the PTP results between thrombin (or PAF) in the presence of MDHC and between thrombin (or PAF) in the presence of genistein. Therefore, although both inhibitors are PTKIs, they have different effects on the PTP induced by either agonist. Our work has produced the first evidence of PTP in equine platelets. It is probable that the changes in PTP are related to events in the signal transduction pathway.
Factors affecting motion characteristics of frozen‐thawed stallion spermatozoa
Authors: HEITLAND A. V. , JASKO D. J. , SQUIRES E. L. , GRAHAM J. K. , PICKETT B. W. , HAMILTON C.
Published: April 2010

Five experiments were conducted to evaluate damage incurred in each processing step for cryopreservation of stallion spermatozoa. In Experiment 1, semen was centrifuged for 9 centrifugation times and the percentage of spermatozoa recovered after each treatment was calculated and spermatozoal motion characteristics analysed. Recovery of spermatozoa was ≥80% when spermatozoa were centrifuged for ≥10 min. Experiment 2 evaluated spermatozoa cryopreserved at 5 different concentrations in each of 2 extenders (skim milk‐egg yolk‐glycerol, SM‐EYG; and lactose‐EDTA, LAC). In SM‐EYG, TMOT and PMOT were higher at spermatozoal concentrations of 20, 200 and 400 times 106/ml (51%/41%, 52%/44%, 50%/43%, respectively) than for samples frozen at ≥800 times 106 spermatozoa/ml (41%/35%, 32%/27%; P<0.05). Spermatozoa frozen in LAC at a concentration of 20 times 106/ml resulted in the highest TMOT and PMOT (43% and 30%, respectively, P<0.05). The effect of freezing rate on motion characteristics of spermatozoa was evaluated in Experiment 3. The VCL of spermatozoa frozen in SM‐EYG was the only parameter affected by freezing rate (P<0.05). Experiment 4 evaluated motion characteristics after cryopreservation of spermatozoa in different sized straws (0.5 or 2.5 ml) in each of 2 extenders (SM‐EYG and LAC). In SM‐EYG, PMOT (38%) and VCL (109 μm/s) were highest when spermatozoa were frozen in 0.5 ml straws (P<0.05). In Experiment 5, spermatozoa thawed immediately after cryopreservation or thawed after storage in liquid nitrogen for 24–48 h were evaluated. There was no effect of length of storage in liquid nitrogen on spermatozoal motion characteristics (P<0.05). Experiment 6 evaluated the effects of cooling time to 5°C (0, 2.5 and 5 h) on motion characteristics of spermatozoa cryopreserved in 2 extenders (SM‐EYG and LAC). TMOT and PMOT were effected by cooling time, and there was a cooling‐time‐by‐extender interaction (P<0.05). In SM‐EYG, TMOT and PMOT were higher if spermatozoa were cooled to 5°C prior to initiation of freezing than if freezing was initiated at 20°C (P<0.05).

A suggested protocol for cryopreservation of stallion spermatozoa would include: 1) centrifugation at 400 g for 14 to 16 min; 2) extension at 23°C with SM‐EYG to 400 times 106 spermatozoa/ml; 3) cool to 5°C for 2.5 h; 4) package in 0.5 ml straws at 5°C; 5) freeze in liquid nitrogen vapour at −160°C; and 6) thaw for 30 s in 37°C water.
Limb movement adaptations in horses with experimentally induced fore‐ or hindlimb lameness
Authors: BUCHNER H. H. F. , SAVELBERG H. H. C. M. , SCHAMHARDT H. C. , BARNEVELD A.
Published: April 2010

The kinematic patterns of all limbs of 11 clinically nonlame Dutch Warmblood horses were studied during induced supporting limb lameness to gain insight into the compensation mechanisms horses use to manage lameness and to test kinematic limb variables for their significance as lameness indicators. Using the locomotion analysis system CODA‐3, the kinematics of the horses were recorded while walking (1.6 m/s) and trotting (3.5 m/s) on a treadmill. A transient lameness model, evoking pressure on the hoof sole, was used to induce 3 degrees of fore‐ and hindlimb lameness. Joint angle patterns and hoof movements were analysed using joint angle/time diagrams and the hoof trajectories in the sagittal plane. Quantitative analysis of 13 selected variables in each limb was done using a 2‐way analysis of variance.

Hyperextension of the fetlock joint and flexion of the coffin joint during the stance phase decreased significantly (P<0.05) in the lame limb, both in fore‐ and hindlimb lameness, at both gaits. In the contralateral nonlame limbs, both variables increased compensatorily. Flexion increased with increasing lameness in the proximal joints, i.e. the shoulder joint and even more the tarsal joint of the lame limb. The retraction of both forelimbs decreased during forelimb lameness at the walk, while in the lame hindlimb the protraction decreased. The hoof arcs were lower in the lame limb than in the nonlame limb, due to an increased hoof height in the nonlame limb during forelimb lameness and to a decreased height in the lame limb during hindlimb lameness.

It was concluded that patterns of the distal joints reflect the different loadings of the limbs during lameness. Proximal joints acted as load dampers to reduce peak forces in the lame limb. Hyperextension of the fetlock and flexion of the coffin joint proved to be the most sensitive indicators for fore‐ and hindlimb lameness.
Head and trunk movement adaptations in horses with experimentally induced fore‐ or hindlimb lameness
Authors: BUCHNER H. H. F. , SAVELBERG H. H. C.M. , SCHAMHARDT H. C. , BARNEVELD A.
Published: April 2010

The kinematic patterns of head and trunk were studied in horses during induced supporting limb lameness to understand the mechanisms horses use to compensate for lameness and to evaluate different symmetry indices for their significance as lameness indicators. Using the locomotion analysis system CODA‐3 the kinematics of 11 clinically nonlame Dutch Warmblood horses were recorded while walking (1.6 m/s) and trotting (3.5 m/s) on a treadmill. A transient lameness model, evoking pressure induced pain on the hoof sole, was used to induce 3 degrees of fore‐ and hindlimb lameness. Peak vertical displacement, velocity and acceleration of head, withers,tuber sacraleand bothtuber coxaewere quantified at different phases of the stride. Changes in these variables due to lameness and symmetry indices calculated as quotients of the values during the lame and nonlame stance phase were analysed using a 2‐way analysis of variance.

The head, withers andtuber sacraleshowed a similar sinusoidal pattern in their vertical displacement, velocity and acceleration. During both fore‐ and hindlimb lameness at the trot, the vertical velocity of the trunk at impact of the lame limb decreased (P<0.05), during the lame stance phase the trunk was kept higher above the ground, maximal acceleration decreased and displacement amplitude was smaller than without lameness. Changes in movements of the head were much more expressed than movements of the withers during forelimb lameness and reversed during hindlimb lameness. At the walk, head movement patterns changed in the same way as at the trot, while withers andtuber sacralepatterns were hardly changed. Symmetry indices of all landmarks showed changes due to increasing lameness at the trot. The maximal vertical acceleration of the head and displacement amplitude of thetuber sacraleproved to be the best indicators to quantify a fore‐ and hindlimb lameness, respectively.
Radiographic and arthroscopic findings associated with subchondral lucency of the distal radial carpal bone in 71 horses
Authors: DABAREINER R. M. , WHITE N. A. , SULLINS K. E.
Published: April 2010

Case records and radiographs of 71 horses with subchondral lucency, without radiographic evidence of fracture, located on the distal radial carpal bone were examined retrospectively. All horses had lameness and/or joint effusion referable to the carpus. Distal radial carpal bone subchondral lucency was found as a solitary lesion or as a lesion concurrent and symmetric to a contralateral distal radial carpal bone chip fracture. The lesion appeared radiographically as a lucency or shadow on the distal dorsal margin of the radial carpal bone and was most evident on the flexed lateromedial and dorsolateral‐palmaromedial oblique projections. Sixty‐four joints in 55 horses underwent arthroscopic surgery. Surgical findings included osteochondral fragmentation in 44 joints, cartilage fragmentation with subchondral bone softening in 17 joints and cartilage fraying in 3 joints. Corresponding third carpal bone lesions were observed in 18 joints and moderate to severe synovitis was present in 24 joints. Carpal bone subchondral radiolucency without a fracture fragment observed on radiographs indicated cartilage and bone damage. In some cases, small chip fractures (1–2 mm) were present within the cartilage debris examined at surgery, yet were not radiographically visible. Follow‐up information was obtained on 50 of the operated horses and 14 nonoperated horses. Forty (80%) of the surgically treated horses returned to racing, with 34 (68%) of these horses (20 of 26 with subchondral lucency as a solitary lesion) racing at a level of competition equal to or better than the pre‐injury level. Of the 14 horses which were not operated, 6 (42%) returned to racing of which only 2 (14%) raced at the same pre‐injury level of competition. Radiographic evidence of radial or intermediate carpal bone subchondral lucency is an indication of cartilage and bone damage which is best treated with arthroscopic surgery.
Computed tomographic evaluation of head diseases in the horse: 15 cases
Authors: TIETJE S. , BECKER M. , BÖCKENHOFF G.
Published: April 2010

The rapid development of software and technology now allows a large amount of diagnostic information to be obtained from a computed tomographic examination. This imaging technique can also be usefully applied to the horse, given appropriate premises and a custom built table for accurate positioning. Computed tomography of the skull has considerable advantages over other techniques, as structures are viewed without superimposition. Fifteen cases are used to demonstrate how through high image quality (precise detail, reduction in artefacts) and objective measurement of density, various pathological changes can be analysed and exact diagnoses achieved. In particular, short measurement and examination times allow preoperative imaging under general anaesthesia giving significant information to assist subsequent surgery.
Effect of a warm‐up on energy supply during high intensity exercise in horses
Authors: Tyler Catherine M. , Hodgson D. R. , Rose R. J.
Published: April 2010

The V̇O2max in racehorses is approximately double that of elite human athletes and the rate of increase in V̇O2 at the onset of high intensity exercise is much greater than in man. The kinetics of gas exchange are affected by a warm‐up prior to exercise in humans, there being a greater aerobic contribution to high intensity exercise after warm‐up. Our hypothesis was that a warm‐up would increase aerobic energy delivery in racehorses during high intensity exercise. Thirteen fit Standardbred racehorses ran to fatigue at 115% of V̇O2max on a treadmill at 10% slope. Prior to acceleration, horses were exercised either for 5 min at 50%V̇O2max followed by 5 min walk, or walked for 2 min. Samples of expired gas were collected every 10 s during the run for determination of V̇O2 and V̇CO2 and measurement of maximal accumulated oxygen deficit (MAOD). Blood lactate concentration was measured 5 min post exercise. We found that with a warm‐up, horses had faster kinetics of gas exchange and a greater proportion of their total energy requirement was supplied by aerobic sources. The aerobic contribution to total energy requirement with and without warm‐up was, respectively, 79.3 ± 1.0% and 72.4 ± 1.7% (P<0.01). There was also a higher MAOD (P< 0.01) in horses that had not been given a warm‐up (mean ± s.e.m. 34.7 ± 2.6 and 47.3 ± 2.6 ml O2 eq/kg bwt with and without a warm‐up respectively). However, there were no significant differences in total run time or estimated total energy expenditure between the 2 protocols. We concluded that during high intensity exercise to fatigue lasting 1 to 2 min, more than 70% of energy supply is from aerobic energy sources and that this contribution is even greater when the horses have received a warm‐up.
Tendon strain in the forelimbs as a function of gait and ground characteristics andin vitrolimb loading in ponies
Authors: RIEMERSMA D. J. , VAN DEN BOGERT A. J. , JANSEN MARGOT O. , SCHAMHARDT H. C.
Published: April 2010

Strains in the tendons of them. flexor digitalis superficialis(superficial digital flexor, SDFT) andm. flexor digitalis profundus(deep digital flexor, DDFT) tendons, the accessory ligament of the deep digital flexor muscle (inferior check ligament, ICL) and them. interosseus medius(suspensory ligament, SL) of 5 ponies were recorded at the walk and trot using mercury‐in‐silastic strain gauges (MISS), on a hard surface (brick pavement) and on sand. The horses were shod with normal, flat shoes.

On pavement, strain in the SDFT, DDFT and SL increased significantly from the walk (2.19%, 1.15% and 3.36%, respectively) to the trot (4.15%, 1.70% and 5.78%, respectively), but that in the ICL did not change significantly (5.36% at the walk, 4.88% at the trot). Strains in the ICL and SL were higher on pavement than on sand (P<0.1) and strains in the SDFT and DDFT were not significantly different. Tendon strain in the SDFT and SL, but not in the ICL and DDFT, increased (P<0.1) in a pony at the walk on pavement with a rider.

Post mortemloading of the same instrumented limbs revealed that the metacarpophalangeal joint could be further extended when the elbow joint was extended. Thein vitrotendon strain was different from thatin vivo, implying that results fromin vitrolimb loading tests have only limited value for assessing tendon functioningin vivo.
Equine herpesvirus type 2: prevalence and seroepidemiology in foals
Authors: MURRAY M. J. , EICHORN EVELYN S. , DUBOVI E. J. , LEY W. B. , CAVEY D. M.
Published: April 2010

Whole blood and serum were collected from foals to determine the prevalence of Equine herpesvirus type 2 (EHV2) infection in foals, age at which infection can first be identified and serological responses to infection. Equine herpesvirus type 2 was isolated from peripheral blood mononuclear cells (PBMC) from 68 of 69 foals, 1–8‐months‐old, sampled once. Virus isolation was performed twice at intervals of 2–7 months on PBMCs from 33 foals and EHV2 was isolated on both occasions in all but one foal (negative, then positive). Regression analysis of log2‐transformed reciprocal serum EHV2 virus neutralising (VN) titres revealed that in foals age 1–7 months, EHV2 VN antibody titre was positively correlated with age (r = 0.94). Paired serum samples were obtained from 58 foals, with the first samples collected age 1–6 months and the second samples collected 2–4 months later. There were significant (P<0.05) increases in mean VN titres to EHV2 in foals sampled initially at age 1–4.

Eight foals had blood sampled prior to sucking and at age 7, 20, 30 and 45 days. Each foal was negative for EHV2 in PBMC and each foal had a negative serum EHV2 VN titre immediately after birth. Each foal was positive for EHV2 in PBMC by age 45 days, with the earliest isolation at 25 days.

Tracheal aspirate fluid and peripheral blood were collected from 20 foals without clinical signs of respiratory disease and from 30 foals with clinical signs of lower respiratory disease. In 20 foals without clinical signs of respiratory disease, EHV2 was isolated from tracheal aspirates (1/20 foals) and PBMC (20/20 foals) and in 30 foals with such clinical signs, from trachea aspirates (20/30 foals: P<0.01) and from PBMC (30/30 foals). In one 6‐month‐old foal, EHV1, but not EHV2, was isolated from the tracheal aspirate, 3 months after EHV2 had been isolated from a tracheal aspirate. These results demonstrate a greater prevalence of EHV2 in lower respiratory secretions in foals with clinically apparent lower respiratory disease, but a cause and effect relationship between the virus and lower respiratory disease remains to be elucidated. It is noteworthy, however, that of virus isolations performed on 50 tracheal aspirates, a virus (EHV1) other than EHV2 was isolated only once.
Histomorphological endometrial status and influence of oxytocin on the uterine drainage and pregnancy rate in mares
Authors: RASCH KATHRIN , SCHOON H. A. , SIEME H. , KLUG E.
Published: April 2010

The aim of this field study was to examine the influence of the uterotonic substance oxytocin in 2 different therapeutic dosages of 15 and 25 iu, respectively on the uterine drainage of oestrous mares and on their fertility. In addition endometrial biopsies of mares with and without intrauterine fluid accumulations around the time of ovulation were evaluated histomorphologically regarding the aetiology of susceptibility to uterine infection.

A population of 59 Hanoverian Warmblood mares was used in this study. The mares were divided intoGroup A(mares with intrauterine fluid accumulations [n = 49]) andGroup B(controls [n = 10]).Group Awas further subdivided into 3 groups according to varying oxytocin administrations (none, 15 iu, 25 iu). Prior to insemination, all mares were examined by rectal palpation, ultrasonography and vaginal inspection.

In addition, hormone plasma concentrations were evaluated at the time of ovulation, namely oestradiol and progesterone concentrations. Endometrial biopsies were obtained from all mares. Endometrial samples for microbiological and cytological evaluation were taken from mares ofGroup Aonly. All mares were inseminated close to ovulation during the first cycle.

This study shows that intravenous oxytocin treatment of mares with intrauterine fluid accumulations results in better pregnancy rates than no treatment.
Effects of flunixin, tolfenamic acid, R(−) and S(+) ketoprofen on the response of equine synoviocytes to lipopolysaccharide stimulation
Authors: LANDONI M. F. , FOOT R. , FREAN S. , LEES P.
Published: April 2010

The objective of this study was to analyse the effects of 4 nonsteroidal anti‐inflammatory drugs (NSAIDs) on the production of β‐glucuronidase (β‐glu), tumour necrosis factor alpha (TNFα), interleukin‐6 (IL‐6), interleukin‐1 (IL‐1) and prostaglandin E2(PGE2) by lipopolysaccharide (LPS)‐stimulated equine synoviocytes. The agents studied were flunixin, tolfenamic acid, S(+)ketoprofen (KTP) and R(‐)ketoprofen.

LPS‐induced release of β‐glu from synoviocytes was inhibited in a concentration dependent manner by all 4 compounds, tolfenamic acid being the most potent. Of the 2 KTP enantiomers, S(+)KTP exerted the greatest inhibitory effect. Tolfenamic acid and flunixin increased the production of IL‐6‐like activity by LPS‐stimulated synoviocytes only at the highest concentration studied (1000 μmol/l). Lower concentrations produced no effect on IL‐6. Flunixin, tolfenamic acid and S(+)KTP produced statistically significant and concentration related increases in the release of IL‐1‐like activity by LPS‐stimulated synoviocytes. Prostaglandin E2synthesis was markedly inhibited in a concentration dependent manner by the 4 NSAIDs. However, R(‐)KTP was effective only at the highest concentrations investigated (1000 and 100 μmol/l).

The present findings are compatible with the possibility that longterm use of NSAIDs in arthropathies, by removing the regulator role of PGE2on IL‐1 synthesis, might enhance the pathological process of cartilage degeneration.
Pharmacokinetics of ceftriaxone in healthy horses
Authors: RINGGER N. C. , PEARSON E. G. , GRONWALL R. , KOHLEPP S. J.
Published: April 2010

Five healthy Equidae (4 horses and one pony) were given a single i.v. dose of ceftriaxone (50 mg/kg bwt) to determine the pharmacokinetics and concentration in cerebrospinal fluid (CSF). Blood was drawn from an i.v. jugular catheter and CSF from a pre‐placed, intrathecal catheter. Serum and CSF concentrations were determined by high performance liquid chromatography. The mean serum concentration of ceftriaxone was 144.7 μg/ml 15 min after injection and declined to 0.3 μg/ml 10 h after injection. The elimination rate constant (Λ2) was 0.63 ± s.e. 0.23/h, the elimination half‐life (t1/2) was 1.62 ± s.e. 0.42 h apparent volume of distribution at steady state (Vd(ss)) was 330.8 ± 11.8 ml/kg bwt. Clearance was 312.7 ± 38 ml/h/kg bwt and mean residence time was 1.13 ± 0.14 h. Mean CSF concentration was 0.60 ± 0.14 μg/ml at 3 h after injection and 0.4 ± 0.31 μg/ml at 8 h. Ceftriaxone may be useful in the treatment of bacterial infections in horses. Its ability to penetrate the CSF should make it effective in the treatment of bacterial meningitis.
Kinematics of the distal hindlimb during stance phase in the fast trotting Standardbred
Authors: JOHNSTON C. , ROEPSTORFF L. , DREVEMO S. , KALLINGS R.
Published: April 2010

Fast trotting Standardbred horses were filmed along a straight on an oval dirt track. Five consecutive stance phases were analysed to describe the planar kinematics of the distal hindlimb. The rapid changes in the geometry of the distal hindlimb that occur during the early stance phase were studied. The hoof segment was initially braked vertically and moved in the direction of the horse. The hoof moved forward on the track surface for more than 20% of the stance time (ST). Two specific deviations in the otherwise smooth course of the fetlock joint angle appeared at 16 and 29% of ST. Tarsal angular joint displacement was, on the other hand, more smooth throughout the stance phase. Segment angular velocity was greatest in the proximal pastern segment, while the metatarsus was almost totally braked in its forward rotation during the early stance. Tibial angular velocity was more smooth and greater than that of the metatarsus. Initial vertical braking of the hoof was related to the rapid rotation of the proximal pastern segment, while the metatarsal and proximal pastern segment angular velocities decreased as the hoof was braked horizontally. Also coincident with horizontal braking of the hoof was an increase in the angular velocity of the tibial segment.

It was concluded that the horizontal as well as the vertical braking of the hoof affect the disto‐proximal braking of the segments of the distal hindlimb during the early stance phase. The early stance phase changes in the distal hindlimb suggest rapid changes in the internal forces of the limb and should be of importance to the orthopaedic health of Standardbred trotters. These rapid changes at the fetlock joint and hock joint during the early stance may be important in lameness as excessive rapid and repetitive loading and movement are thought to induce joint damage (Radin et al. 1991).
Ultrasonographic examination of the femorotibial articulation in horses: imaging of the cranial and caudal aspects
Authors: CAUVIN E. R. J. , MUNROE G. A. , BOYD J. S. , PATERSON C.
Published: April 2010

The aim of this study was to determine the normal ultrasonographic features of the cranial and caudal aspects of the femorotibial articulation and, in particular, to establish a method of examining the menisci, cruciate and meniscal ligaments ultrasonographically. Twenty hindlimbs isolated post mortem from 10 horses were used to study the normal ultrasonographic and gross anatomy of the femorotibial joint. Five stifles from 3 normal, live horses were also examined with B‐mode, real‐time ultrasound imaging. The results of the anatomical study are presented. The joint surfaces, menisci, cruciate and meniscal ligaments could be imaged adequately in all the specimens. No obvious variations in shape or echotexture, that might impair visualisation of potential lesions, were observed. The authors suggest that ultrasonography is a potential, noninvasive means of diagnosing soft tissue lesions in the femorotibial joint.