ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04212.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04213.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryArchaeological evidence of horse domestication dates from 4000 BC in the Eurasian Steppes of the Ukraine. There, Indo‐Europeans rode horses and herded them for meat. This had profound social and economic consequences which led to the development of nomadic equestrian cultures. The earliest direct evidence of riding is from Mesopotamian plaques, and correspondence of the Kings of Mari (2000 BC). Indo‐Europeans brought the horse to the Near East and there, outside its natural habitat, used specialised knowledge to raise and train horses on a large scale for military use. Hittite instructions on training chariot horses are contained in the Kikkuli text from Anatolia (1350 BC). Systematic conditioning, grain feeding and elements of ‘interval training’ are notable. Equine prescriptions were also recovered from Ugarit (Syria) which indicate a rational approach to veterinary medicine in the same era. With the evolution of effective training and tools, chariots, metal bits, and the recurve bow, horses became formidable weapons of war. Mounted bowmen succeeded chariots in warfare, particularly nomadic Scythians who dominated Central Asia (1000‐500 BC). In the Middle East (Iraq), Assyrians assembled a powerful military empire and employed a vast and skilled cavalry (900‐612 BC). The first surviving text on training cavalry mounts is by the Athenian General Xenophon (400 BC) who reveals a sensitive understanding of the horse. Although the horse has been used for herding, transportation and sport, a recurring stimulus for horsemanship throughout history has been its mi

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04214.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThe microcirculation of the dermal laminae and papillae of the equine foot from seven clinically normal Australian ponies was studied using an improved microvascular casting corrosion technique and scanning electron microscopy. Casts of veins, arteries, capillaries and arteriovenous anastomoses (AVAs) were readily identified by their characteristic surface morphology. Arteries entered the laminar circulation axially, between pairs of axial veins, and were connected to each other by smaller calibre interconnecting arteries. Short abaxial branches of the axial interconnecting arteries gave rise to tufts of predominantly, proximodistally orientated, capillaries arranged abaxially in rows. The laminar veins anastomosed with each other extensively (the axial venous plexus) and formed most of the vascular skeleton of casts of the dermal laminae. AVAs were found throughout the laminar circulation but the largest and longest (40μ diameter) were found clustered close to the origin of the axial arteries. The density of the laminar AVAs was estimated to be 500 AVAs/cm2. Blood vessels of the dermal papillae of the periople, coronary band, distal laminae, sole and frog shared a basic structural organisation. The cast of each papillary unit consisted of a central artery and vein enmeshed in a sheath of fine capillaries. At intervals along the length of the central artery were short branches which gave rise to tufts of capillaries. The capillaries formed a tortuous anastomosing plexus which encircled the papillary unit and drained into the central vein at intervals along its length. AVAs were always present at the base of the papillary units and anastomoses connected the central artery and vein. AVAs are important components of the dermal microcirculation of the equine foot and their distribution and density is compatible with their proposed role in the pathophysiology of equine laminitis

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04215.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04216.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryInfection of seronegative Welsh mountain ponies was established by intranasal instillation or exposure to nebulised aerosol of egg grown H3N8 viruses. Pyrexia and coughing were noted following intranasal instillation and high titres of virus were recovered from the nasopharynx. Exposure to aerosol resulted in more severe clinical signs characterised by high temperatures, dyspnoea, anorexia and coughing; lower levels of virus were recovered from the nasopharynx. The severity of clinical signs and the kinetics of virus shedding were dose‐related with the minimal infectious dose being 102EID50/ml when ponies were exposed to aerosols produced by nebulisation of 20ml allantoic fluid. Full clinical signs only developed when ponies were exposed to a dose of 106EIU50/ml. It was concluded that exposure to nebulised aerosols of egg grown H3N8 viruses was a more reliable method of inducing clinical influenza than intranasal inoculation and would be more suitable for challenge studie

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04217.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThe ultrasonic appearance of seven cases of granulosa cell tumour is described, and compared with an ovarian haematoma and an ovarian serous cystadenoma. The granulosa cell tumours varied from being uniformly dense to having one or several large fluid filled cysts. Some tumours resembled the haematoma or cystadenoma and also, in some aspects, normal ovarian structures such as corpora haemorrhagica or follicles in early pregnancy. There was no typical ultrasonographic appearance of the granulosa cell tumours which enabled definitive diagnosis. However, ultrasound may be a diagnostic aid when used in conjunction with the history and findings on rectal palpation.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04218.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryPlasma progesterone concentrations were measured in 179 mares bled on alternate days commencing with a positive pregnancy diagnosis on Days 17 to 18 after ovulation and concluding on Days 42 to 45. During this period 17 mares (10 per cent) lost their pregnancies, 11 before Day 25. In 15 mares the timing of the pregnancy loss could be determined with adequate accuracy; in only one did a decline in progesterone precede the loss. Thus pregnancy loss between Days 17 and 42 was rarely caused by a fall in plasma progesterone.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04219.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryTechniques and normal radiographic anatomy for positive and double contrast shoulder arthrography in horses were evaluated. General anaesthesia was used for most radiographic projections of the shoulder. The mediolateral projection provided the most information during arthrography, although the supinated mediolateral view occasionally allowed better definition of the cartilage surfaces on the medial aspects of the humeral head. The craniocaudal mediolateral oblique and caudocranial projections provided limited additional information. Water soluble non‐ionic contrast agents, such as metrizamide and iohexol, were suitable for shoulder arthrography; iohexol resulted in less synovitis and lameness. Arthrography in cases of osteochondrosis and osteochondritis dissecans allowed better evaluation of cartilage attachment to subchondral bone, better evaluation of the length and depth of cartilage lesions and more accurately defined the site and shape of osteocartilaginous free bodies. Cartilage thickening without detachment from the subchondral bone could only be determined by arthrography. Although these thick cartilage regions may later dissect from the subchondral bone, most cases where the cartilage was firmly adherent were not candidates for surgical debridement and carried a favourable prognosis. The determination of a free flap by arthrography indicated the need for surgery. Extensive humeral and glenoid cavity lesions were better defined by arthrography, allowing a rational decision between surgical debridement or euthanasia. Using arthrography, evaluation of the size and patency of the communicating canal to a subchondral cystic defect better separated cases with long, narrow and poorly patent canals for conservative rather than surgical therap

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04220.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThe technique of impedance plethysmography is described and its application to observation of lung volume changes in the horse at exercise is discussed. The results from horse at rest show that there is a close relationship between rate of lung volume change (flow rate) and the associated impedance changes during both inspiration and expiration. Impedance changes during exercise were related to inspiration and expiration by observation of associated respiratory sounds. Artefacts related to technical difficulties are also indicated.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1990.tb04221.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY