bluuebunny/crossref_metadata_2025_split huggingface dataset:
An ultrastructural study of the equine lower respiratory tract
Authors: PIRIE MYRTLE , PIRIE H. M. , CRANSTON SHEILA , WRIGHT N. G. 
Published: April 2010

SummaryThe surface features of the lower respiratory tract of 20 clinically normal horses of different ages and types were studied with scanning electron microscopy. Parallel light microscopical and transmission electron microscopical studies were also carried out. The ciliary carpet was virtually complete from the trachea to the lobar bronchi. In small bronchi, ciliation was less complete allowing numerous non‐ciliated mucous cells to become obvious. The terminal bronchioles, populated mainly by non‐ciliated bronchiolar epithelial cells, had an abrupt junction with alveolar ducts. Interalveolar pores were common particularly in older horses.
Ultrastructural findings in horses with chronic obstructive pulmonary disease (COPD) II: pathomorphological changes of the terminal airways and the alveolar region
Authors: KAUP F.‐J. , DROMMER W. , DAMSCH S. , DEEGEN E. 
Published: April 2010

SummaryExtensive light and electron microscope studies (transmission and scanning electron microscopy) of the bronchioles and alveolar region, in 28 horses suffering chronic obstructive pulmonary disease (COPD) and eight control horses, revealed good correlation between clinical severity and morphological changes. In the bronchiolar epithelium the non‐ciliated bronchiolar epithelial (Clara) cells, in particular, showed ultrastructural alterations and, even in the mild stages of disease, these presented degenerative changes and lack of differentiation. Together with loss of granulation in the Clara cells and metaplasia of the goblet cells, cells were seen with unusual intracytoplasmic lamellar inclusion, the number of which increased sharply with clinical severity. The focal changes in the alveolar region were necrosis of type I epithelial cells, alveolar fibrosis of varying degrees with type II epithelial transformation and emphysema or hyperinflation, with an increase in Kohn's pores. Some horse also showed morphological signs of interference with the surfactant system, in the form of marked cysts with lamellar structure. The alveolar changes were mostly in the peribronchiolar region and were, therefore, interpreted as reactive processes. No conclusions as to the aetiology of equine COPD can be derived from these morphological investigations.
Cardiopulmonary effects of xylazine sedation in the foal
Authors: CARTER S. W. , ROBERTSON SHEILAH A. , STEEL CYNTHIA J. , JOURDENAIS D. A. 
Published: April 2010

SummarySix healthy foals underwent instrumentation for measurement of the cardiopulmonary effects of sedation with 1.1 mg/kg bodyweight xylazine hydrochloride given intravenously. Responses to xylazine in foals at 10 and 28 days of age were not significantly different. Foals became sedate and markedly ataxic, and four of the six foals became recumbent. Heart rate decreased significantly but no arrhythmias were detected. Arterial blood pressure increased initially and then fell significantly below pre‐injection values. Changes in respiratory airflow, upper airway obstruction and respiratory noise were noted in the initial 20 mins of sedation, after which respiratory rate fell, tidal volume increased, and minute volume decreased gradually. Arterial blood gas tensions and pH did not change significantly during the 120 mins following xylazine administration. Control studies showed no significant changes. All foals recovered uneventfully.
Anatomical validation of two‐dimensional echocardiography in the horse
Authors: VÖRÖS K. , HOLMES J. R. , GIBBS CHRISTINE 
Published: April 2010

SummaryThis study was performed on 15 horses to validate the cardiac anatomy as imaged with two dimensional echocardiography (2DE) and to determine the accuracy of intracardiac measurements. 2DE images were recorded in five horses in life with a Diasonics DRF100 ultrasound system and a 3.5 MHz transducer in different tomographic planes. After slaughter, the hearts were fixed in 10 per cent formalin. To comparein vivoandin vitroresults, the specimens were suspended in a water‐filled tank and 2DE images were made using the same transducer positions as in life.In vitro2DE and autopsy measurements of the same planes and parameters were also taken on a further 10 hearts, and the results were statistically compared. Thein vivo2DE images corresponded well with bothin vitro2DE recordings and anatomical sections. Repeatable imaging of each tomographic plane was possible on the post mortem hearts using intracardiac reference points. Comparison of parameters measured duringin vitro2DE and autopsy demonstrated a significant correlation between all 2DE and autopsy data (r: 0.879 to 0.926; P<0.001). Repeated 2DE measurements of each parameter showed a good reproducibility with coefficients of variation (CV%) varying between 4.6 to 10.6 per cent. The results suggest that 2DE is a reliable method for accurate anatomical evaluation of the equine heart and show the potential application of quantitative two dimensional echocardiography in the living horse.
Scintigraphic evaluation of digital circulation during the developmental and acute phases of equine laminitis
Authors: TROUT D. R. , HORNOF W. J. , LINFORD R. L. , O'BRIEN T. R. 
Published: April 2010

SummaryScintigraphy was used to evaluate digital circulation at 24 h intervals in 11 control horses and in nine horses affected with acute laminitis created by administration of a high‐starch ration. Following intra‐arterial injection of technetium‐99m macroaggregated albumin into the brachiocephalic trunk, static images were acquired of the right front foot. Dynamic radionuclide angiograms and static blood pool images were also obtained after jugular vein injection of technetium‐99m diethylenetriamine pentaacetic acid. These procedures were performed on standing horses, using either minimal or no tranquillisation. Images were analysed quantitatively for parameters indicative of circulation to the whole foot and to specific regions within the foot. There was no evidence of reduced total blood flow to the lamellae during either the developmental or acute phases of laminitis. Total flow tended to increase throughout the peripheral/external regions of the foot, but statistically significant elevations were consistently present only within the lamellae. The increased total blood flow to the lamellae may have been due to elevated capillary flow and/or elevated arteriovenous shunt flow. This study did not support lamellar ischaemia as the primary cause of acute equine laminitis.
In vitroresponses of equine digital vessels to dopamine and fenoldopam
Authors: BAXTER G. M. , MOORE J. N. , TACKETT R. L. 
Published: April 2010

SummaryThein vitroresponses of isolated vascular preparations of digital arteries and veins obtained from healthy anaesthetised horses were determined for dopamine and fenoldopam. The digital vessels were harvested, cut into 4 mm vascular segments, suspended in tissue baths and attached to force‐displacement transducers. Dose‐response studies between 10−8and 10−4M concentrations were performed for all drugs. The change in tension of each vascular ring was measured in grams of force. The reactivity between palmar and plantar digital vessels and baseline vascular responses were determined for dopamine. The vascular responses of dopamine were compared toin vitrodata for other known vasoconstrictor agents. The mechanism of vasoconstriction induced by dopamine was further defined using prazosin, a specific competitive alpha‐1 adrenoceptor antagonist. The vasodilating ability of fenoldopam, a dopamine‐1 (DA‐1) receptor agonist, was also determined using noradrenaline‐ preconstricted vascular segments from palmar digital vessels. The effective concentration to produce 50 per cent of the maximal response (EC50) and the maximal contraction in grams of force per milligram of the vascular ring (g/mg) were calculated. There were no differences in the reactivity between the palmar and plantar digital vessels. Dopamine produced intense constriction in arteries and veins but only at very high molar concentrations. Prazosin decreased significantly the sensitivity of the veins to dopamine (increased the mean EC50values) but not the arteries. Prazosin had no effect on the maximal contractions of the vessels. Fenoldopam produced very little relaxation of either the arteries or veins. These results suggest that dopamine produces constriction in equine digital arteries and veins and that the constriction is only partially mediated by alpha‐1 adrenoceptors. Also, fenoldopam produced minimal DA‐1 receptor activation in these peripheral vessels.
Squamous cell carcinoma of the equine external genitalia: a review and assessment of penile amputation and urethrostomy as a surgical treatment
Authors: HOWARTH S. , LUCKE V. M. , PEARSON H. 
Published: April 2010

SummaryA retrospective analysis was performed on 48 cases of suspected neoplasia involving the equine external genitalia. Forty nine squamous cell carcinomata (SCC) and 23 squamous papillomata (SP) were identified. Two cases of epithelial hyperplasia and one case of habronemiasis were also recognised histopathologically. The glans penis was the most common site of tumour development accounting for 53 per cent of cases of SCC and 61 per cent of SP. The urethral diverticulum, urethral process or urethra was involved in 27.6 per cent (8/29) of cases of SCC. Twelve per cent (5/41) of cases of SCC were confirmed to have metastatic involvement of the local lymph nodes. Papillomata showing pre‐malignant changes were identified in five cases. Seventy five per cent (36/48) of the animals presented were ponies. All were geldings, mean age 16.5 years. Penile amputation and urethrostomy, preputial ablation and proximal urethrostomy or local excision were used in the surgical management of these animals; three cases were inoperable and destroyed at presentation. Oedema, haemorrhage and stenosis of the urethrostomy site were encountered as post operative complications. Sixty six per cent (6/9) of animals with SCC of the glans penis (without urethral involvement), which had a known history over the follow up period, treated by penile amputation and urethrostomy survived for longer than 18 months. Similarly, of those with urethral involvement only 28.6 per cent (2/7) survived for a similar follow‐up period. SCC not uncommonly affects the external genitalia of aged pony geldings and frequently the glans penis. If the lesion is identified before local metastasis occurs, penile amputation and urethrostomy is indicated and the prognosis is favourable.
Muscle disorders in the horse: a retrospective study
Authors: FREESTONE J. F. , CARLSON G. P. 
Published: April 2010

SummaryCase records of horses with muscle disorders presenting to the Veterinary Medical Teaching Hospital of the University of California, Davis, over a nine year period were evaluated. The objectives of the review were to identify the common myogenic muscle problems and their clinical features. Muscle disease of idiopathic aetiology following exercise was by far the most common condition noted. Other causes of myogenic muscle disorders included congenital, infectious, immune‐mediated and nutritional factors.
Muscle fibre type composition in untrained and endurance‐trained Andalusian and Arab horses
Authors: LOPEZ‐RIVERO J. L. , MORALES‐LOPEZ J. L. , GALISTEO A. M. , AGUERA E. 
Published: April 2010

SummaryMuscle biopsies were taken from the middle gluteal muscle of 68 stallions (52 Andalusian [AN] and 16 Arab [AR]) ranging from six to 12 years of age. Seventeen AN horses and eight AR horses were untrained, while the remainder underwent active endurance training for 6 months. Fifteen AN horses were moderately endurance‐trained while the other 20 AN horses and eight AR horses were strongly endurance‐trained. Percentages of type I and type II fibres were similar in all groups (P>0.05). The group of horses with the hardest training had a higher percentage of type HA fibres (AN P<0. 01; AR P<0.02) and a lower percentage of type IIB fibres (P<0.05 for AN and AR) than the untrained horses. All trained horses had a higher percentage of type IIB oxidative fibres and a lower percentage of type IIB non‐oxidative fibres than the untrained horses (P<0.01 for both). These results suggest that the proportions of type I and type II fibres are highly stable within a given breed, but the stimulus of training facilitates changes both in contractile properties and, particularly, in the oxidative capacity of type II subgroups.
Preferential denervation of the adductor muscles of the equine larynx I: muscle pathology
Authors: DUNCAN I. D. , AMUNDSON J. , CUDDON P. A. , SUFIT R. , JACKSON K. F. , LINDSAY W. A. 
Published: April 2010

SummaryThe laryngeal muscles of 18 horses were examined histologically. The neurogenic changes found in each muscle were scored by four reviewers and the results evaluated statistically. Fifteen of these horses had endoscopic evidence of abnormal laryngeal function, three of which were defined as having adductor paralysis. Measurement of muscle fibre area in two horses with idiopathic laryngeal hemiplegia (ILH) was performed. In the quantitative study of neurogenic change, the adductor muscles were more significantly affected than the abductor muscle. This was also true in the clinical cases of ILH where measurement of muscle Fibre area demonstrated that the lateral cricoarytenoid (adductor) muscle showed a wider range of pathological changes than the dorsal cricoarytenoid muscle (abductor). Those horses with the most severe muscle pathology also had the most abnormal endoscopic findings. The propensity for denervation of the adductor muscles should provide clues as to the pathogenesis and natural history of horses with sub‐clinical laryngeal disease and ILH.
Preferential denervation of the adductor muscles of the equine larynx II: Nerve pathology
Authors: DUNCAN I. D. , REIFENRATH P. , JACKSON K. F. , CLAYTON M. 
Published: April 2010

SummaryThe terminal branches of the recurrent laryngeal nerve (RLN) of three normal ponies and six horses with sub‐clinical laryngeal disease were examined qualitatively and quantitatively in an attempt to explain the preferential denervation of the laryngeal adductor muscles in the neuropathy of idiopathic laryngeal hemiplegia (ILH). The myelinated fibre spectra of all the motor nerve fibres in the left and right abductor and adductor branches of the RLN in three normal ponies were measured. The density of myelinated fibres was also calculated. There was no significant difference between the larger group of myelinated fibres in the adductor or abductor branches. In the six horses with laryngeal hemiparesis, however, there was a marked preferential loss of the medium/large size myelinated fibres in the left adductor branch, although nerve fibre densities were not significantly different. While no simple morphometrical feature was found to explain the selective muscle denervation, the greater loss of large diameter myelinated fibres in the adductor branches confirms the earlier observation of adductor muscle susceptibility in the neuropathy of ILH.
An outbreak of Equid herpesvirus abortion in New South Wales
Authors: CARRIGAN M. , COSGROVE P. , KIRKLAND P. , SABINE MARGARET 
Published: April 2010

SummaryThirty‐three of the 44 mares on a Thoroughbred stud in New South Wales aborted or lost foals within one day of birth. Gross pathological and histological changes were in keeping with Equid herpesvirus I (EHV‐1) abortion. In the six foals that underwent virological examination, EHV was isolated and typed as EHV‐1 by restriction endonuclease analysis. EHV‐1 abortion had not occurred previously on this stud and the source of the infection was not identified.
An investigation of the incidence of chronic obstructive pulmonary disease (COPD) in random populations of Swiss horses
Authors: BRACHER VERENA , von FELLENBERG R. , WINDER CHRISTINE N. , GRUENIG GABRIELE , HERMANN M. , KRAEHENMANN A. 
Published: April 2010

SummaryThe incidence of Chronic Obstructive Pulmonary Disease (COPD) in Switzerland was determined in three groups of horses selected at random. Group A (97 horses) and Group B (93 horses) had no history of respiratory disease, but Group C (113 horses) had a history of lower respiratory tract disease. All horses were examined by auscultation of the respiratory tract under forced, breathing, endoscopic examination of the upper and lower. respiratory tract, arterial blood gas analysis at rest and cytological examination of respiratory secretions (RS). Fifty‐four per cent of the horses in Group A and 54.8 per cent of Group B were diagnosed as suffering clinical COPD and only 12.4 per cent of horses in Group A and 8.6 per cent in Group B had no detectable abnormalities in their lower respiratory tracts. In Group B, 19.4 per cent were considered to be suffering from parasitic pulmonary disease indicated by elevated numbers of eosinophils in their RS. Pharyngeal lymphoid hyperplasia was exhibited in 70.1 per cent of Group A and 74.2 per cent of Group B. Cytological examination of RS was useful to determine if the secretions found in the trachea originated from the upper or lower respiratory tract. Arterial blood gas analysis revealed no significant differences between healthy horses and those with subclinical or mild COPD.
Osteochondritis dissecans of the tarsocrural joint: results of treatment with arthroscopic surgery
Authors: McILWRAITH C. W. , FOERNER J. J. , DAVIS D. M. 
Published: April 2010

SummaryThe technique and results of arthroscopic surgery for the treatment of osteochondritis dissecans in 318 tarsocrural joints in 225 horses are reported. Of the 225 horses, 154 were racehorses or intended for racing. Arthroscopic surgery was an effective technique for treating osteochondritis dissecans of the tarsocrural joint. The overall functional ability and cosmetic appearance of the limbs were excellent. Post surgical follow‐up information was obtained for 183 horses, of which 140 (76.5 per cent) raced successfully or performed their intended use following surgery. Of the remaining 43, 11 were considered to still have a tarsocrural joint problem, 19 developed other problems precluding successful performance, eight were considered poor racehorses without any lameness problems identified, three were killed because of septic arthritis and two died from other causes. There was no significant effect of age, sex or limb involvement on the outcome. The size of the intermediate ridge lesions had no effect on prognosis but the presence of degenerative or erosive changes in the articular cartilage significantly decreased the prognosis. The synovial effusion resolved in 117/131 racehorse joints (89.3 per cent) and 64 of 86 non‐racehorse joints (74.4 per cent) with follow‐up. The outcome for synovial fluid resolution was significantly inferior for lesions of the lateral trochlear ridge of the talus or medial malleolus of the tibia compared to distal intermediate ridge lesions. There was no significant relationship between resolution of effusion and successful performance outcome.
Arthroscopic removal of osteochondral fragments of the palmar/plantar aspect of the metacarpo/metatarsophalangeal joints
Authors: HOUTTU JUKKA 
Published: April 2010

SummaryThis paper presents the results of arthroscopic surgery in 42 Standardbred trotters and three Finnish horses. Forty‐five horses were operated on. The age range was one to seven years; 73 per cent of the horses were three years old or younger. Horses showed a variety of clinical signs ranging from moderate to severe lameness at slow speeds, to obscure lameness manifesting only at high speeds. Synovial effusion of the fetlock joint was rare. In this series, 44 horses that had Type I fragments and one horse that had Type III fragments were operated on. Of the 45 horses operated on, 23 (51 per cent) returned to speed training in three months and 41 (91 per cent) returned to speed training in six months. Three of 45 (6 per cent) were lame three months after the surgery when the trainer attempted to start speed training. One of those was sound six months after the operation. The remaining two (4 per cent) stayed lame due to a lesion in the affected joint. Two of 45 (4 per cent) discontinued training for other reasons. The horse with Type III fragments returned to speed training in three months.
Relative incidence of dorsal metacarpal disease in young Thoroughbred racehorses training on two different surfaces
Authors: MOYER W. , SPENCER PAMELA A. , KALLISH MICHELE 
Published: April 2010

SummaryThe relative incidence of dorsal metacarpal disease was examined in two groups of Thoroughbred racehorses training on dissimilar surfaces (dirt and wood fibre). The horses and training methods appeared to be similar. The incidence of disease was significantly greater in the group training on dirt. There was no significant difference in the age distribution of incidence between the two groups and there was no association of incidence with sex or age within the training group. The number of fast miles worked by the two groups prior to the onset of dorsal metacarpal disease was lower in the group training on dirt.
Assessment of the breeding prognosis of mares using paired endometrial biopsy techniques
Authors: RICKETTS S. W. , ALONSO SILVIA 
Published: April 2010

SummaryPaired endometrial biopsy samples were taken from 530 subfertile mares, before and after treatment (where indicated) and a period of sexual rest. Prognoses were made after each biopsy (Categories 1A‐4A before treatment and Categories 1B‐4B after treatment), using histopathological criteria similar to those described by Kenney and Doig (1986). Eighty‐seven per cent of the mares were assigned to first biopsy prognosis Category 3A. The second biopsy prognosis produced a more even population distribution (10, 47, 40 and 3 per cent respectively for Category 1B, 2B, 3B and 4B mares). First biopsy Category 3A and 4A mares produced mean foaling rates of 51 and 40 per cent respectively. None of the 14 second biopsy Category 4B mares delivered a live foal (12 were barren, one aborted and one suffered early foetal death). This study supports the hypothesis that a breeding prognosis assigned on the basis of two endometrial biopsy samples, taken before and after specific uterine treatment, where indicated, which takes into consideration the mare's ability to respond to treatment, is likely to be more accurate than one assigned after a single biopsy sample.
The effect of age and parity on the development of equine chronic endometrial disease
Authors: RICKETTS S. W. , ALONSO SILVIA 
Published: April 2010

SummaryThe results of a retrospective analysis of 3,804 endometrial biopsy specimens collected from non‐pregnant mares during the course of routine equine stud farm practice demonstrates a significant and practically useful correlation between the severity of chronic degenerative endometrial disease (CDE) diagnosed and age of mare at the time of examination. There were significant correlations between the number of foals born and the mares' barren years prior to biopsy and the severity of CDE, but the differences were not sufficiently large to be useful. Correlations between the severity of chronic infiltrative endometritis (CIE) and age or pre‐biopsy parity were minimal. The results suggest that using similar histopathological criteria to those used by Kenney and Doig (1986), mares up to nine years of age should have no signs of CDE, mares up to 13 years of age should have no more than mild signs, mares up to 15 years of age should have no more than moderate signs and mares aged 17 years or older are likely to have severe signs. We believe that these guidelines are a useful, objective aid for formulating a breeding prognosis.