Measurement of vertical forces and temporal components of the strides of horses using instrumented shoes

Instrumented shoes were used to measure the vertical forces exerted by horses moving at a variety of gaits. Two types of shoes were used; one contained a single transducer positioned over the center of the frog and the second contained transducers located at the toe and both sides of the heel. Horses were shod with these instrumented shoes and walked and trotted over a force plate. Forces were simultaneously recorded from the transducers in the shoes and from the force plate. Comparisons were made between the amount and duration of the forces exerted on the transducers and the vertical and horizontal forces recorded from the force plate. Forces recorded from the single transducer shoes showed strong correlations with the forces recorded from the force plate for horses moving at the walk; however, at the trot only moderate correlations occurred between these forces. At both the walk and trot, forces recorded from each side of the heel and the total forces occurring on all three transducers from the front hooves of horses shod with three transducer shoes showed strong correlations to the vertical forces recorded from the force plate.Vertical forces were also recorded from the instrumented shoes as horses walked, trotted and galloped on a track straightaway. Forces recorded from normal horses shod with single transducer shoes on all four feet were greater on the forelimbs than the rear limbs at the walk and trot. At the gallop, forces were highest on the lead front followed by the nonlead front, lead rear and nonlead rearlimb, respectively. Forces recorded from a three transducer shoe on the right front hoof of a horse walking, trotting and galloping in a right lead were highest on the medial side of the heel and occurred during the middle of the support period. Peak forces on the toe occurred at or near the time of heel lift.The results of these studies indicate that these instrumented shoes have advantages over the methods previously used to measure locomotor forces. These instrumented shoes can be used to simultaneously record the temporal components and the amount and distribution of vertical forces exerted during consecutive strides of horses moving at a variety of gaits.     

A RADIOGRAPHIC STUDY ON THE DEVELOPMENT OF THE ANTEBRACHIUM IN GREAT DANE PUPS, RAISED UNDER STANDARDIZED CONDITIONS

Radiographic examination of the antebrachium was performed in 16 healthy Great Danes, raised under standardized conditions, at six-week intervals from 9 to 27 weeks of age. The dogs were fed according to the National Research Council's nutrient requirements of dogs (1974). The development of the secondary ossification centers and the growth in length of the radius and ulna were noted. In the majority of dogs changes in the shape and structure of the distal ulnar metaphysis resembled disturbances in cartilage maturation and bone maturation and remodelling. An improvement in the radio-graphic appearance of the distal ulnar metaphysis was noted at the age of 27 weeks. It is concluded that the delicate processes that are involved in skeletal development may be frequently disturbed in fast growing, giant-breed dogs, without causing clinical problems.     

Abnormal hepatic copper storage in a teleost fish (Morone americana)

Excessive copper storage in livers of feral white perch (Morone americana) from the Chesapeake Bay is described. Age-related, progressive accumulation of hepatic copper in levels often exceeding 1,000 micrograms/g wet weight was associated with peribiliary fibrosis and inflammation, bile duct hyperplasia, prominent, enlarged melanomacrophage centers, and disruption of hepatic architecture in older fish. Levels of zinc were mildly elevated compared to striped bass (Morone saxitilis) and adult rats. Cholangiomas were found in two perch. Rubeanic acid-stained liver had abundant copper-positive cytoplasmic granules in hepatocytes and cells of melanomacrophage centers. Subcellular fractionation showed that 90% of hepatocellular copper was in nuclei/cell debris fractions (which also contain tertiary lysosomes). Using electron probe microanalysis, high copper levels were localized in hepatocellular cytoplasmic bodies. Resolution of hepatic cytosol by gel permeation chromatography indicated that approximately 50% of the cytosolic copper in the white perch was bound to non-specific high molecular weight proteins, with the remaining 50% eluting at a peak where rat metallothionein is located. Ultrastructural examination revealed abundant lysosomes, increased size and number of peroxisomes, and increased density and numbers of mitochondrial matrix granules. This study indicates that white perch may be a model for studying effects of excessive copper accumulation and cellular mechanisms which control copper kinetics.     

Serological survey for leptospiral antibodies in goats in St Elizabeth Parish,Jamaica, 1985–1986

A serological survey of goats in St Elizabeth Parish, Jamaica, comprising the breeding herd at the Agricultural Development Corporation (ADC) facility at Hounslow, five commercial herds and 21 family herds was carried out in 1985-1986. The Leptospira microscopic agglutination test indicated that one or more serovars in the Canicola serogroup were the most prevalent. Repeated samplings of goats at ADC, Hounslow demonstrated an increase in portlandvere and canicola seropositive animals following the onset of warmer weather and of icterohaemorrhagiae seropositive animals following the autumn rains and cooler weather. Apart from a cluster of family goats seropositive to pomona there was no geographical separation of reactors to the other serovars tested in the parish.     

Endocarditis in a cow

Bacterial endocarditis of the tricuspid valve was diagnosed in a cow with weight loss, reduced milk production, and intermittent fever. Clinical signs of disease included jugular and mammary vein pulses, tachycardia, large cardiac silhouette, and grade-III/V holosystolic murmur. The diagnosis was also supported by echocardiographic findings and isolation of Streptococcus viridans from blood samples. The cow was treated with penicillin, furosemide, acetylsalicylic acid, heparin, and potassium chloride and survived 14 months after the diagnosis, producing 1 live calf and 4 viable embryos. The cow's heart rate exceeded an upper normal limit of 80 beats/min during most of the initial 4 months of treatment. Additional clinical signs of disease that were observed during treatment included diarrhea, ventral edema, and coughing. General medicine and cardiology textbooks have previously minimized the potential benefits of anticoagulant use in cases of septic endocarditis. The advent of routinely performed embryo transfer procedures may make treatment of endocarditis feasible in cattle with exceptional genetic merit.     

National survey of clinical and subclinical mastitis in Jamaican dairy herds, 1985–1986

Summary Between April 1985 and August 1986, 89 Jamaican dairy herds with 10 or more cows were visited, 1, 645 lactating cows were examined using the CMT test and 254 composite milk samples collected for bacteriological examination. Widespread management faults were noted, especially of milking machine usage and maintenance and the abuse of antibiotics. Fifty-six per cent of all quarters were found to have CMT scores of one or higher, 0·8% showed clinical mastitis and 3·2% were blind. The most common bacterial pathogenStaphylococcus aureus, was recovered from 31% of sampled cows. The resultant milk loss from clinical and subclinical mastitis was estimated to be 20% of the potential national production.

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Resumen Se visitaron 89 hatos lecheros con 10 o más, vacas en Jamaica, entre abril 1985 y agosto 1986. Se examinaron un total ede 1·645 vacas lactantes, por medio de la prueba California para mastitis, colectando a la vez 254 muestras compuestas de leche, para exámenes, bacteriológicos. Se detectaron un sinnúmero de fallas en el manejo, especialmente relacionados con el uso y mantenimeiento de las máquinas de orde?o, y con el abuso de antibióticos. Cincuenta y seis por ciento de todos los cuartos tenían mastitis clínica y 3·2% estaban ciegos. El patógeno más común fue elStaphylococcus aureus, el cual se recuperó de 31% de las vacas examinadas. La pérdida de leche resultante de mastitis clínica o subclínica, se calculó en un 20% de la producción nacional potencial.

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Résumé Entre avril 1985 et ao?t 1986, 89 troupeaux laitiers jama?cains de 10 vaches et plus, ont fait l'objet d'une enquête. 1645 vaches en lactation ont été contr?lées à l'aide du test californien pour le dépistage de la mammite (CMT) et 254 prélèvements de lait de mélange ont été récoltés pour un examen bactériologique. Des erreurs fréquentes de conduite du troupeau ont été notées particulièrement dans l'emploid des machines à traire et dans leur entretien ainsi que dans l'abus des antibiotiques. 56 p. 100 des quartiers avaient un résultat égal ou supérieur à 1 ou plus au test californien (CMT), 0,8 p. 100 étaient atteints d'une mammite clinique et 3,2 p. 100 étaient “secs”. Le germe pathogène le plus fréquent,Staphylococcus aureus a été trouvé chez 31 p. 100 des vaches examinées. On estime a 20 p. 100 du potential national de production la perte de lait résultant de ces mammites cliniques et subcliniques.

     

Cervical vertebral malformations

Cervical vertebral malformations are recognized clinically when they result in spinal cord compression causing neurologic deficits. Confirmation of diagnosis is based on radiographic and myelographic evidence of cord compression. Medical therapy is not usually successful. Several successful surgical treatments are described.