ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03768.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03769.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03770.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryPlacentation between 80 and 220 days of gestation was studied by measurement of fetal dimensions and gross, light and transmission and scanning electron microscopic examinations of the allantochorion and endometrium from 4 fertile mares with no, or very mild, endometrial histopathology and 6 subfertile Thoroughbred mares suffering varying degrees of age‐related chronic degenerative endometritis (endometrosis). Spontaneously occurring twin gestation was observed in 3 animals. Several of the subfertile mares had endometrial cysts which showed 2 distinct features during pregnancy: those located near the lumenal surface of the endometrium showed no sign of microcotyledon development in both the endometrium and the opposed, flat and smooth allantochorion, whereas endometrial cysts located deeper in the stroma were covered by apparently normal glands and microcotyledons. Fetal dimensions were lower in the subfertile mares, but still within the reference range. Microcotyledon development appeared to be delayed and the chorionic macro‐ and microvilli looked shorter and blunter between 80 and 120 days in the 2 subfertile mares compared to the 2 fertile mares at the same gestational ages. At 120 days, the subfertile mare had significantly less microvilli per surface area than her fertile counterpart and her fetus weighed only half that from her counterpart, despite a similar crown‐rump length. However, between 160 and 220 days the difference in microcotyledon development between the young fertile and old subfertile mares was much less marked, despite the continued existence of considerable numbers of distended 'gland nests' in the endometrium of the latter

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03771.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryThe synthesis and expression of collagentypes II, VIandXwere investigated in growth cartilage selected from a group of 31 horses and ponies in the age range 157 days of gestation to 12 years. Collagen isolation, immunolocalisation andin situhybridisation techniques were used in order to provide information on the pattern of synthesis of these 3 collagens during endochondral ossification in normal horses.Type IIcollagen immunoreactivity and mRNA expression was found in each of the 3 zones of growth cartilage chondrocytes in all samples studied, whereas the localisation of both collagentypes VIandXvaried during cartilage developmentType VIcollagen in the fetus was present only in the resting and upper proliferative zones and around the cartilage canal blood vessels in both articular/epiphyseal and metaphyseal cartilage, whereas in animals age>2 years it was present throughout all the cartilage studied.Type Xcollagen immunoreactivity and mRNA expression was detected only in the late hypertrophic zone in articular/epiphyseal cartilage in animals age<6 months and in metaphyseal cartilage in animals<12 months.These results demonstrated the presence of collagentypes VIandXin equine cartilage for the first time. In addition, the pattern of expression oftype IImRNA in the cartilage has been established andtype VIandXcollagens have been shown to differ in their expression during development of the skeleton.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03772.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryMares with complicated pregnancies (illness, problems at parturition or delivery of an abnormal foal, n = 30) were scanned transabdominally from 298 days gestation to term in order to measure fetal size, evaluate fetal well‐being and characterise the intrauterine environment. The results of the last scan obtained prior to parturition were compared to normal data obtained from fetuses of comparable gestational age to develop a biophysical profile specific for the equine fetus. Twelve mares produced a normal foal (positive outcome) and 18 mares delivered 19 abnormal foals (negative outcome). Both fetuses that were inactive throughout the entire scan and 4 of 5 fetuses with heart rate abnormalities were abnormal at birth. Three of 4 fetuses surrounded by decreased allantoic fluid quantities had a negative outcome. All mares with large anechoic spaces between the uterus and placenta (n = 3) and/or thickened uteroplacental units (n = 5) delivered abnormal foals. There was a significant correlation between fetal aortic diameter and neonatal foal weight in these complicated pregnancies (P<0.0001, r = 0.85). Fetal aortic diameters were predicted from maternal weight and 6 fetuses had smaller than predicted aortic diameters, all with negative outcomes.A biophysical profile of the equine fetus from 298 days gestational age to term was developed that included 6 factors related to pregnancy outcome: fetal heart rate, fetal aortic diameter, maximal fetal fluid depths, uteroplacental contact, uteroplacental thickness and fetal activity. The profile proved informative about fetal well‐being, perinatal morbidity and perinatal mortality. A low score was a definite indication of an impending negative outcome; however, a high score was not assurance of a positive outcome. The utility of such a biophysical profile and future directions for research are discus

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03773.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryFlorfenicol was administered to horses and ponies at a dose rate of 22 mg/kg bwt by i.v., i.m. and oral routes. Following i.v. administration it had an elimination half‐life of 1.8 ± 0.9 h, a body clearance of 0.4 ± 0.11/h.kg and a volume of distribution at steady‐state of 0.7 ± 0.2 1/kg. It was highly bioavailable following i.m. (81%) and oral (83%) administration. Less than 15% of the administered dose was excreted unchanged in the urine during the 30 h following administration. Animals treated with florfenicol had elevated bilirubin concentrations. Florfenicol was well tolerated by animals in the present study although all animals had loose faeces following administration by each route. At present, florfenicol cannot be recommended for clinical use until multiple dose studies have been carried out to confirm its

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03774.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryThe effectiveness of spinal accessory nerve branch biopsy evaluation as a means to confirm the diagnosis of equine motor neuron disease (EMND) was investigated. Sixteen horses with histories and clinical signs suggestive of EMND and 16 control horses with neither histories nor clinical signs of any neurological disorder, were subjects of the study. Biopsy samples of the ventral branch of the spinal accessory nerve were obtained either surgically, under general anaesthesia orpost mortemimmediately after euthanasia. Evaluation was done on the spinal cord of all horses to serve as the definitive diagnostic indicator of EMND.Results indicate that biopsy of the ventral branch of the spinal accessory nerve is a reliableante mortemdiagnostic test for EMND. Histological evidence of the degeneration of myelinated axons is present in both acute and arrested cases. The ventral branch of the spinal accessory nerve is easy to approach surgically and biopsy of the nerve causes no disfigurement of thesternocephalicusmuscle. The use of semi‐thin Epon sections is an excellent method of sample preparation. Formalin fixation and routine paraffin embedment may prove more accessible and provide good quality preparations for reliable interpretation. In the hands of an experienced pathologist, the sensitivity and specificity reliability coefficients for spinal accessory nerve branch biopsy are 94%, making this technique an extremely valuable diagnostic tool for theante mortemdiagnosis of EMN

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03775.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryClinical features, treatment and outcome of 15 horses with penetrating thoracic wounds are described. The most common cause of trauma was collision with an object (10 horses). Concurrent clinical findings included subcutaneous emphysema (12 horses), pneumothorax (12 horses), haemothorax (5 horses) and pneumomediastinum (6 horses). Axillary wounds were present in 5 horses. Foreign bodies were identified and removed from 2 horses. Wounds were sutured (6 horses) or packed (7 horses). Air was evacuated from the pleural cavities of 11 horses. Eleven horses (73%) were discharged from the hospital. All horses subjected to euthanasia had severe trauma to structures outside the thoracic cavity including perforation of the colon (2 horses), renal trauma (1 horse) and a luxated thoracolumbar vertebra (1 horse). From this study, it can be concluded that 1) the prognosis for horses with penetrating thoracic wounds, without extrathoracic injury, is favourable; 2) a thorough evaluation including the abdominal cavity should be performed and 3) horses with axillary wounds should be monitored closely for respiratory distress until the wound has completely healed.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03776.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryThe objective of this study was to determine if damage to the articular cartilage alone or articular cartilage plus subchondral bone of the distal medial femoral condyle of young, exercised horses resulted in the formation of subchondral cystic lesions. Twelve Quarter Horses (age 1–2 years), free of clinical and radiographic signs of osteochondrosis and lameness were used. In 6 horses(Group 1), a 15 times 1 mm linear full thickness defect in the articular cartilage was made arthroscopically on the weightbearing surface of the distal aspect of the medial femoral condyle. In the other 6 horses(Group 2), a 15 times 3 mm full thickness elliptical cartilage defect was made, followed by burring a 5 mm diameter, 4 mm deep hole into the subchondral bone. Three weeks after surgery, all horses were hand walked and trotted for 2 weeks and then exercised for 6 min daily, 5 days a week for the next 14 weeks on a treadmill. They were then turned onto a small paddock for 6 weeks (6 months total). The development of subchondral cystic lesions was determined using radiography. Bone activity in the femoral condyle was monitored with nuclear scintigraphy. All horses that developed subchondral cystic lesions radiographically were subjected to euthanasia for gross and histological examination of the lesions.No subchondral cystic lesions and no clinical abnormalities were detected in the horses inGroup 1.Subchondral cystic lesions developed radiographically in 5 of 6 horses in(Group 2).Scintigraphic findings of horses with subchondral cystic lesions were inconsistent. Histological examination of lesions revealed variable quantities of fibrous connective tissue, fibrocartilage and bone, with evidence of bone remodelling adjacent to the subchondral cystic lesion. The results suggest that damage to articular cartilage plus subchondral bone, but not articular cartilage alone, of the distal medial femoral condyle may lead to the development of subchondral cystic lesions. These findings indicate that all subchondral cystic lesions in horses may not be osteochondrosis‐type lesions and that trauma to weightbearing articular surfaces of young horses may be a predisposing fac

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1996.tb03777.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY