bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation
Authors: MARLIN D. J. , SCOTT CAROLINE M. , SCHROTER R. C. , HARRIS R. C. , HARRIS PATRICIA A. , ROBERTS C. A. , MILLS P. C. 
Published: April 2010

SummaryTo investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30°C and 80% RH. Training consisted of a combination of long duration low‐intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11 ± 3°C and 74 ± 2% RH. Before (PRE‐ACC) and after acclimation (POST‐ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3‐day event, at 30°C/80% RH.Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE‐ACC 141 ± 8 ml/min/kg bwt vs. POST‐ACC 145 ± 9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount ofPhase Din the CET (PRE‐ACC 6.3 ± 0.3 min vs. POST‐ACC 7.3 ± 0.3 min, P<0.05; target time = 8 min).Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail‐skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSKfor a given TPAand a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPAor TTSKon either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPAor TTSKfollowing acclimation (P<0.05).The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent with a humid heat acclimation response. These changes were mostly similar to those reported to occur in man and other species and were consistent with thermal acclimation and an increased thermotolerance, leading to an improved exercise tolerance. It is concluded that a 15 day period of acclimation is beneficial for horses from cooler and or drier climates, that have to compete in hot humid conditions and that this may redress, to some extent, the decrement in exercise tolerance seen in nonacclimated horses and reduce the risk of heat related disorders, such as heat exhaustion.
A field survey on the distribution of strongyle infections of horses in Sweden and factors affecting faecal egg counts
Authors: LIND E. OSTERMAN , HÖGLUND J. , LJUNGSTRÖM B.‐L. , NILSSON O. , UGGLA A. 
Published: April 2010

SummaryFaecal egg counts were performed during the first quarter of 1995 on samples from 1183 horses of varying breeds, ages and gender on 110 farms in 3 regions of Sweden. The majority of the horses had been treated with ivermectin or pyrantel when stabled the previous autumn. The risk of reinfection with strongyles between treatment and sampling was therefore considered to be minimal. Consequently, the results reflect primarily the occurrence of worms originating from inhibited strongyle larvae refractory to anthelmintic treatment. A total of 922 (78%) individuals were found to shed strongyle eggs, and 15 (14%) of the farms studied had at least one horse infected withStrongylus vulgaris.There was a significant, gradual decrease in faecal egg output in horses originating from the southern to the northern part of Sweden. Horses from studfarms showed significantly higher numbers of strongyle eggs/g faeces (EPG) as compared to those on other types of farms, such as riding‐schools and boarding stables. However, there was no correlation between herd size and mean herd EPG. The output of strongyle eggs was highest in horses aged 2 and 3 years. EPG values then declined with increasing age of the horse. Horses treated with ivermectin in the previous autumn showed significantly lower EPG values than untreated horses and those treated with pyrantel pamoate.
Naturally occurring osteoarthritis in the metacarpophalangeal joints of wild horses
Authors: CANTLEY CHARLOTTE E. L. , FIRTH E. C. , DELAHUNT J. W. , PFEIFFER D. U. , THOMPSON K. G. 
Published: April 2010

SummaryThis study identified changes consistent with osteoarthritis; articular cartilage damage, subchondral bone sclerosis and marginal osteophytes, in the metacarpophalangeal joints of wild New Zealand horses. The articular cartilage lesions were identified by Indian ink staining techniques and histology. The lesions occurred on the proximodorsal aspect of the first phalanx (P1) and were more severe on the medial compared to the lateral eminence of the bone, and their severity increased with age. The bone mineral density of the subchondral bone underlying the cartilage lesions, assessed using conventional radiography and dual energy absorptiometry, also increased with age and with severity of the overlying cartilage lesion. Subjective assessment of cabinet radiographs revealed that the subchondral bone sclerosis was greater in horses with severe articular cartilage damage. Ossicles, with a distinct trabecular bone pattern, were identified at the proximo‐dorsal margin of P1 in 8 specimens from 5 horses from the older age groups (greater than age 5 years).The results of this study demonstrate age‐related changes consistent with osteoarthritis in the metacarpophalangeal joints of wild horses. There appears to be a significant relationship between subchondral bone sclerosis and overlying cartilage degeneration in the proximodorsal aspect of P1. We have identified an age‐related osteoarthritic process naturally present in horses; and postulate that the stresses of racing and training may accelerate this ageing process.
Aetiopathogenesis of parasagittal fractures of the distal condyles of the third metacarpal and third metatarsal bones ‐ review of the literature
Authors: RIGGS C. M. 
Published: April 2010

SummaryFractures are the cause of considerable morbidity and mortality among Thoroughbred racehorses. A significant proportion of these injuries occur in the absence of any particular traumatic incident. Evidence of prefracture pathology interpreted as fatigue damage has been identified in some such cases, but the aetiology of many of these so‐called ‘spontaneous’ fractures remains obscure. Parasagittal fractures of the third metacarpal (McIII) and third metatarsal (MtIII) bones are one of the more common fractures to affect Thoroughbred racehorses. The configuration of each of these fracture types is highly consistent, suggesting a predisposition of the bones to these injuries. Several theories have been proposed to explain the aetiopathogenesis of these fractures although none has so far stood up to critical examination. The current paper reviews the literature relating to parasagittal fractures of McIII and MtIII.
Three dimensional structure of the distal condyles of the third metacarpal bone of the horse
Authors: BOYDE A. , HAROON Y. , JONES S. J. , RIGGS C. M. 
Published: April 2010

SummaryThis study examined the three‐dimensional (3D) microarchitecture of regions of the equine third metacarpal bone (McIII) commonly involved in distal condylar fractures. Limbs were obtained from Thoroughbred horses (neonates to age 24 years) destroyed for inoperable fractures and a variety of other conditions. Beams, blocks and sections were cut in the principal axes, some embedded in PMMA and others examined unembedded. Several methods were used to study the 3D structure, including conventional and confocal optical microscopy, scanning electron microscopy (SEM) and radiography. The mineralised articular cartilage tends to cleave in the sagittal plane. Proximal to the subchondral bone, the main trabeculae are robust plates running in the sagittal direction with less significant mediolateral connections. Small blood vessel canals lie inside the sagittal plates. This structure gives maximum strength and protection in the sagittal plane in which the bone rotates, but offers minimal resistance to fracture propagation in this plane. The anatomical course of the common distal condylar fractures of the third metacarpal bones can be explained by underlying anisotropic structural features of the mineralised tissues.
PGFM response to exogenous oxytocin and determination of the half‐life of oxytocin in nonpregnant mares
Authors: PACCAMONTI D. L. , PYCOCK J. F. , TAVERNE M. A. M. , BEVERS M. , VAN DER WEIJDEN G. C. , GUTJAHR S. , SCHAMS D. , BLOUIN D. 
Published: April 2010

SummaryWe investigated the half‐life of oxytocin in reproductively normal mares and the prostaglandin response after oxytocin administrations. Mares were given oxytocin, 10 or 25 iu, i.v., on the day of, or 2 days after, ovulation, and frequent jugular blood samples were collected for analysis of oxytocin and Prostaglandin F metabolite (PGFM) by RIA. Neither dose of oxytocin nor day of treatment affected the half‐life of the exogenous oxytocin, which was determined to be 6.8 min. A significant increase in PGFM was observed within 6 min of oxytocin administration and peak values were observed within 10 min. PGFM response after oxytocin administration on the day of ovulation appeared elevated compared to the response 2 days after ovulation.
Indices of oxidative stress in blood and pulmonary epithelium lining fluid in horses suffering from recurrent airway obstruction
Authors: ART TATIANA , KIRSCHVINK NATHALIE , SMITH NICOLA , LEKEUX P. 
Published: April 2010

SummaryTo test the hypothesis that reactive oxygen species could be associated to the lower airway disorders occurring in horses suffering from recurrent airway obstruction (RAO), indices of oxidative stress were studied in blood and pulmonary epithelium lining fluid in 5 RAO horses either in clinical remission or 24 h after the onset of a crisis of bronchospasm and in 5 healthy horses. Venous blood and bronchoalveolar lavage fluid (BALF) samples were collected and analysed for reduced glutathione (GSH), oxidised glutathione (GSSG), total glutathione (TGSH), glutathione redox ratio (GRR) in blood haemolysate and pulmonary epithelium lining fluid (PELF). The haemolysate concentrations of GSH, GSSG, TGSH and GRR were similar in the 3 groups. The PELF glutathione status was significantly different in the RAO horses in acute crisis compared to healthy horses, indicating the occurrence of an oxidative stress. When RAO horses were in crisis their GSH and TGSH remained unchanged but their GSSG and GRR were significantly increased compared to the remission.These results support the hypothesis that oxidative stress is associated with lower airway disorders occurring in horses suffering from RAO.
Radiological measurements from the feet of normal horses with relevance to laminitis
Authors: CRIPPS P. J. , EUSTACE R. A. 
Published: April 2010

SummaryLateromedial radiographic projections were made from the feet of 25 normal horses and 3 angles and 3 distances were measured. From these, normal ranges of calculated variables were obtained. The width and length of each foot and the height of the horse at the withers was also measured. In view of its possible importance in clinical laminitis, particular attention was paid to ‘founder’ distance (D). This is the vertical distance between the proximal limit of the dorsal hoof wall and the proximal limit of the extensor process of the distal phalanx. There were significant differences between breeds inD(P<0.05) and in wall thickness (P<0.01). Further studies investigated the effects of time, differing radiographic projections and different operators onD. Ddid not alter significantly (P>0.05) over a 6 week study period. It was concluded that errors due to radiographic beam obliquity were not of practical importance. Errors in measuringDbetween operators can be minimised by use of a standard radiographic technique. Although there was some variation in the value ofDmeasured over time and with different operators, which could make the interpretation of early or subtle changes difficult, measurement variation was not considered to interfere with the assessment of large changes associated with severe laminitis.
Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes inEquidae
Authors: HASEL KRISTIN M. , SUMMERS B. A. , DE LAHUNTA A. 
Published: April 2010

SummaryIn 3 mature female horses of varying breeds, episodes of colic and depression for 1–4 days preceded an encephalopathic disorder with maniacal behaviour, anxiety, profuse sweating and, in one case, terminal opisthotonus. Blood ammonia levels were elevated approximately 10‐fold. At necropsy, there were gastrointestinal serosal and mesenteric haemorrhages. Histologically, all 3 cases revealed diffuse Alzheimer type II astrocytes in the cerebral grey matter. Alzheimer type II astrocytes were glial fibrillary acidic protein (GFAP) negative or only weakly positive, weakly S‐100 positive, and vimentin negative. In the absence of primary hepatic and/or renal lesions, an increase in intestinal ammonia absorption due to ileus or increased ammonia production by colonic bacteria is hypothesised.
Transabdominal ultrasonographic determination of fetal gender in the horse during mid‐gestation
Authors: RENAUDIN CATHERINE D. , GILLIS CAROL L. , TARANTAL ALICE F. 
Published: April 2010

SummaryGender determination of the equine fetus using transabdominal ultrasonography was studied in 20 mares. One group of 10 research mares was scanned repeatedly every 2 weeks from 100 days gestation to parturition, while the second group of 10 client mares was subjected to echography once during mid‐gestation. In males, the penis and/or prepuce was observed on 71 occasions from 102 days to 258 days gestation. On cross‐sectional views, the male external genitalia had a round shape with parallel linear echogenic foci up to approximately 140 days gestation and then appeared triangular. Fetal testes were oval in shape in frontal view and had an homogeneous ultrasonographic appearance. Females were diagnosed on 23 occasions from 118 days to 227 days gestation based on the presence of the mammary glands and teats. Fetal ovaries appeared homogeneous with a characteristic circular echo from 100 days to 134 days gestation.Gender identifications (n = 98) based on the presence of the penis and/or prepuce in males and mammary glands and teats or fetal gonads in females were all correct, in agreement with the sex of the foals at birth. The optimal window of time was defined in both sexes as 100 to 220 days gestation. Thereafter, it was increasingly difficult to identify the anatomical structures cited above. Fetal sex was mainly determined using the transabdominal approach (87/98). However, the transrectal approach was useful in cases in which fetuses were either in posterior presentation or located very high in the mares abdomen. Good quality diagnostic scanners used typically in equine reproduction and equipped with a 5.0 MHz probe can be used for this procedure up to 160 days gestation, after which a 3.5 MHz transducer is often necessary due to increasing fetal size.
A new isolate of the nematophagous fungusDuddingtonia flagransas biological control agent against free‐living larvae of horse strongyles
Authors: FERNÁNDEZ A. SILVINA , HENNINGSEN E. , LARSEN M. , NANSEN R. , GRØNVOLD J. , SØNDERGAARD J. 
Published: April 2010

SummaryAn experiment was carried out in 1997 to test the efficacy of an isolate of the microfungusDuddingtonia flagransagainst free‐living stages of horse strongyles under conditions in the field and to assess the eventual effect of the fungus on the normal degradation of faeces. Faecal pats were made from faeces of a naturally strongyle infected horse, which had been fed fungal material at a dose level of 106fungal unit/kg bwt. Control pats without fungi were made from faeces collected from the same animal just before being fed fungi. Faecal cultures set up for both groups of faeces to monitor the activity of the fungus under laboratory conditions showed that the fungus significantly reduced the number of infective third‐stage larvae (L3) by an average of 98.4%. Five faecal pats from each batch of faeces were deposited on pasture plots at 3 times during spring‐summer. The herbage around each pat was sampled fortnightly to recover L3transmitted from faeces. The results showed that the herbage infectivity around fungus‐treated pats was reduced by 85.8–99.4%. The remaining faecal material at the end of each sampling period was collected, and the surviving L3were extracted. Significantly fewer larvae were recovered from the fungus‐treated pats. Analysis of wet and dry weight of the collected pats, as well as their organic matter content, were performed to compare the degradation of faeces of both groups. The results indicated that the presence of the fungus did not alter the degradation of the faeces.
The association ofClostridium botulinumtype C with equine grass sickness: a toxicoinfection?
Authors: HUNTER L. C. , MILLER J. K. , POXTON I. R. 
Published: April 2010

SummaryThe cause of grass sickness, an equine dysautonomia, is unknown. The disease usually results in death. Gastrointestinal (GI) dysfunction is a common clinical manifestation in all forms of the disease. It is generally thought that equine grass sickness (EGS) is caused by an ingested or enterically produced neurotoxin which is absorbed through the GI tract.Clostridium botulinumwas first implicated as a causative agent when it was isolated from the GI tract of a horse with EGS in 1919. The aim of the present study was to investigate the hypothesis that EGS results from toxicoinfection withC. botulinumtype C: growth of the bacterium in the GI tract with production of toxin (BoNT/C). Ileum contents and faeces from horses with EGS were investigated for BoNT/C, and indirectly for the presence ofC. botulinumtype C., and compared with control samples from horses without EGS. BoNT/C was detected directly by ELISA in the ileum of 45% (13/29) of horses with EGS compared to 4% (1/28) of controls, and in the faeces of 44% (20/45) of horses with EGS compared to 4% (3/77) of controls. Levels of up to 10 μg toxin/g wet weight of gut contents were observed. The one control horse with detectable toxin in the ileum had been clinically diagnosed as having acute EGS, but this was not confirmed by histopathology. The organism was detected indirectly by assaying for BoNT/C by ELISA after enrichment in culture medium.C. botulinumtype C was shown to be present in 48% (14/29) of ileum samples and 44% (20/45) of faecal samples from horses with EGS, compared with 7% (2/27) of ileum samples and 8% (6/72) of faecal samples from controls. These results support the hypothesis that EGS results from aC. botulinumtype C toxicoinfection.
Retrospective study of subchondral sclerosis and lucency in the third carpal bone of Standardbred trotters
Authors: UHLHORN H. , CARLSTEN J. 
Published: April 2010

SummaryThe aim was to investigate radiographic findings of subchondral sclerosis and subchondral lucency in the dorsoproximal‐dorsodistal (DPr‐DDi) projection of the third carpal bone (C3) in relation to clinical appearance and to prognosis for racing. In a retrospective study, case records of 89 Standardbred trotters diagnosed with traumatic carpitis confirmed with intra‐articular anaesthesia were examined. Records included data on degree of lameness at presentation and after flexion tests and a radiographic examination of the carpus, including a DPr‐DDi projection of the C3. Subchondral lucency was found significantly to influence the degree of lameness at presentation and the time to start but did not significantly affect the chance of racing within 30 months post examination. In the present material no significant relationship between degree of sclerosis and lameness or prognosis for racing within 30 months was found, but the low number of C3 with severe sclerosis limited conclusions about that group.
MMP‐9 as a marker of inflammation in tracheal epithelial lining fluid (TELF) and in bronchoalveolar fluid (BALF) of COPD horses
Authors: RAULO S. M. , SORSA T. , TERVAHARTIALA T. , PIRILÄ E. , MAISI P. 
Published: April 2010

SummaryGelatinolytic activity was analysed to study whether elevated activity previously found at the tracheal level of the respiratory tract of horses with chronic obstructive pulmonary disease (COPD) could also be found at the lower part of the respiratory tract. Furthermore, presence and significance of the gelatinolytic matrix metalloproteinases (MMPs) MMP‐2 and MMP‐9 in respiratory secretions of healthy and COPD horses were determined. Elevated gelatinolytic matrix metalloproteinases were detected in bronchoalveolar and tracheobronchial secretions from COPD horses. The main pathologically elevated MMP was characterised to be MMP‐9. Significantly increased MMP‐9 activities as measured by gelatin zymography and Western blotting were found in all the respiratory samples from COPD horses compared to healthy horses. Elevation of active MMP‐9 paralleled with increased gelatinase‐associated lipocalin levels. Bronchoalveolar lavage fluid (BALF) epithelial cells, macrophages, neutrophils and lymphocytes expressed MMP‐9 immunoreactivity demonstrated by immunocytochemistry and MMP‐9 mRNA was expressed by bronchial epithelial cells of lung tissue section shown byin situhybridisation. MMP‐2 seems not to play a major role in chronic lung inflammation. No clear differences in MMP‐2 or MMP‐14 (a potent MMP‐2 activator) levels were found when comparing the samples from COPD or healthy horses. These results suggests that MMP‐9 could serve as a potential diagnostic marker for the active ongoing tissue remodelling in the acute phase of equine COPD. Increased gelatinolytic activity could be found at both tested respiratory tract levels. Therefore, tracheal epithelial lining fluid (TELF) samples can usefully serve as diagnostic material for detection of increased levels of the main gelatinolytic MMP, MMP‐9, representing the entire diseased lung.