bluuebunny/crossref_metadata_2025 huggingface dataset:
Septic osteitis of the distal phalanx: findings and surgical treatment in 18 cases
Authors: CAUVIN E. R. J. , MUNROE G. A.
Published: April 2010

Eighteen cases of septic osteitis of the distal phalanx were diagnosed clinically and confirmed at surgery over a 6 year period (1990–1996). Focal bone lysis was the most common radiographic finding. Sequestra were identified in 4 horses, one of which was associated with a fractured plantar process. All the horses were treated surgically with open debridement. The septic process recurred in 4 horses: one was subjected to euthanasia due to navicular bursa infection, secondary to a pathological fracture, the other 3 horses responded to further debridement. A pathological fracture occurred in another horse. All the survivors were not lame 3 months post operatively, although complete healing took 1–12 months. Long term follow up was available in 14 cases. One was retired, all the other horses were back in work at a similar level of performance. This series indicates that surgical treatment of septic pedal osteitis carries a fair to good prognosis despite a high rate of post operative complications and convalescence period of up to 12 months.
Macroscopic ‘degeneration’ of equine superficial digital flexor tendon is accompanied by a change in extracellular matrix composition
Authors: BIRCH HELEN L. , BAILEY A. J. , GOODSHIP A. E.
Published: April 2010

Injuries to the superficial digital flexor tendon are common in horses required to gallop and jump at speed. Partial rupture of this tendon usually occurs in the central core of the mid‐metacarpal region and may be preceded by localised degenerative changes.Post mortemexamination of apparently normal equine flexor tendons has revealed an abnormal macroscopic appearance in the central core, characterised by a reddish discolouration. We have previously shown that there is also physical damage to the collagen fibres. In the present study we tested the hypothesis that the abnormal appearance is accompanied by changes in the composition of the extracellular matrix of the tendon. Biochemical analysis of the extracellular matrix demonstrated an increase in total sulphated glycosaminoglycan content, increase in the proportion oftype IIIcollagen and decrease in collagen linked fluorescence in the central core of ‘degenerated’ tendons relative to tissue from the peripheral region of the same tendon. Dry matter content and total collagen content were not significantly different between tendon zones or normal and ‘degenerated’ tendons. These changes suggest a change in cell' metabolism and matrix turnover in the central core of the tendon and are likely to contribute to a decrease in mechanical properties in this part of the tendon, predisposing to the characteristic partial rupture of the tendon.
Ultrasonographic anatomy of the accessory ligament of the superficial digital flexor tendon in horses
Authors: DENOIX J. M. , BUSONI VALERIA
Published: April 2010

The ultrasonographic anatomy of the accessory ligament of the superficial digital flexor tendon (AL‐SDFT) in the horse is presented. Comparison between anatomical sections of isolated limbs and ultrasound scans of the distal antebrachium in sound horses enabled the authors to establish the normal reference ultrasonographic images of this structure. The AL‐SDFT inserts 7–14 cm above the antebrachiocarpal joint on the palmaromedial aspect of the radius. Ultrasonographically it appears as an uniformly echogenic structure located deep to the median artery. The knowledge of ultrasonographic anatomy is essential for identification of abnormal images and assessment of AL‐SDFT damage.
Caesarean section and other methods for assisted delivery: comparison of effects on mare mortality and complications
Authors: FREEMAN D. E. , HUNGERFORD L. L. , SCHAEFFER D. , LOCK T. F. , SERTICH P. L. , BAKER G. J. , VAALA W. E. , JOHNSTON J. K.
Published: April 2010

Data from 116 mares that had caesarean section or vaginal delivery at 2 university hospitals were analysed in 5 groups, as follows: dystocia corrected by caesarean section,Group DCS(n = 48); elective caesarean section,Group ECS(n = 10); caesarean section concurrently with colic surgery,Group CCS(n = 8); assisted vaginal delivery,Group AVD(n = 22); and controlled vaginal delivery under general anaesthesia,Group CVD(n = 28).

Survival rate in all mares that had caesarean section, excludingGroup CCS, was 88% (51/58). All mares inGroup ECSsurvived andGroup CCShad the lowest survival rate (38%). In 98 mares with dystocia,Groups DCS(15%) and AVD (14%) had significantly lower (P<0.05) mortality rates thanGroup CVD(29%). There were no differences between groups for duration of dystocia. The placenta was retained in 75 (65%) of 116 mares, and for a longer period following elective caesarean section than following assisted vaginal delivery. Multiple complications (≥3) were recorded in 6 mares inGroup CVDbut not in the other groups. Of the 102 foals delivered from 98 mares with dystocia, 11 (11%) were alive at delivery and 5 (5%) survived to discharge. Survival rate for foals was 38% inGroup CCS, and 90% inGroup ECS. Under conditions similar to those in this study, it is calculated that caesarean section is preferable toCVDif dystocia is protracted and great difficulty and trauma is invloved, even ifCVDallows delivery of the foal.
An evaluation of the haemostatic suture in hysterotomy closure in the mare
Authors: FREEMAN D. E. , JOHNSTON J. K. , BAKER G. J. , HUNGERFORD L.L. , LOCK T. F.
Published: April 2010

This study was designed to evaluate the haemostatic suture as a means of preventing haemorrhage from the hysterotomy in mares after caesarean section. At 2 university hospitals 1982–1994, 48 mares had caesarean section for dystocia, 10 as an elective, and 8 mares concurrently with colic surgery. The haemostatic suture was used in 31 of 66 mares (47%) and surgery period was significantly (P<0.05) shorter when it was not applied. Anaemia (PCV<30%) was recorded in 13 (22%) of 58 mares, excluding the colic group, and the haemostatic suture did not after this proportion of mares that had anaemia. Anaemia was 5 times more probable following caesarean section than vaginal delivery, evidence that bleeding from the hysterotomy is a serious and common complication of caesarean section in mares. Severe uterine haemorrhage was recorded in 3 mares that had an haemostatic suture (10%) and in 2 mares that did not (6%). The latter two mares died of haemorrhage. The suture, therefore did not eliminate post operative anaemia and severe uterine haemorrhage. If omitted, the hysterotomy should be closed with a full thickness pattern that is sufficiently tight to compress vessels in the uterine wall.
Expression of endothelin in equine laminitis
Authors: KATWA L. C. , JOHNSON P. J. , GANJAM V. K. , KREEGER J. M. , MESSER N. T.
Published: April 2010

Biosynthesis of endothelin‐1 (ET‐1), the most potent endogenous vasoconstrictor yet identified, is increased following myocardial infarction (MI) in man. Pathological events which occur in the connective tissues of the equine hoof during laminitis are similar in some respects, to changes occurring in the myocardial connective tissues following MI in man. The objective of this study was to determine whether ET‐1 expression in connective tissues obtained from the hoof of laminitic horses is increased compared with tissues obtained from healthy horses. Expression of ET‐1 in connective tissues of the equine hoof was measured following tissue extraction from 3 groups of horses: horses in which acute laminitis had been induced by the administration of starch; chronically foundered horses; nonlaminitic horses. The concentration of ET‐1 in laminar connective tissues obtained from all laminitic horses (1573.0 ± 392.8 pg/g of tissue; n = 10) was increased when compared with tissues obtained from nonlaminitic horses (392.5 ± 117.4 pg/g of tissue; n = 5) (P<0.05). The concentration of ET‐1 in laminar connective tissues obtained from the experimentally induced, acute laminitic horses (1043.6 ± 254.4 pg/g of tissue; n = 7) and from the spontaneously affected, chronic laminitic horses (2808.3 ± 878.6 pg/g of tissue; n = 3) was increased compared with the control group (P<0.05, P<0.01, respectively). The concentration of ET‐1 in laminar connective tissues obtained from the chronic laminitic horses was greater than that of the experimentally induced, acute laminitic group (P<0.05). It is suggested that the data provide a strong argument that increased ET‐1 expression in the connective tissues of the equine hoof represent a potentially important and hitherto unrecognised component of the pathophysiology of equine laminitis. Further studies are needed to determine whether inhibitors of ET‐1 converting enzyme or antagonists of ET‐1 receptors might be useful in the treatment and prevention of laminitis in horses.
Results of screw fixation combined with cortical drilling for treatment of dorsal cortical stress fractures of the third metacarpal bone in 56 Thoroughbred racehorses
Authors: DALLAP BARBARA L. , BRAMLAGE L. R. , EMBERTSON R. M.
Published: April 2010

The purpose of this study was to evaluate screw fixation with cortical drilling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs. Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentucky. Fifty‐six Thoroughbred racehorses were treated surgically for stress fracture of MCIII with screw fixation and cortical drilling. Stress fractures occurred primarily in the left front limb of the male 3‐year‐olds, in the dorsolateral cortex of the middle third of MCIII. Ninety‐seven percent of the fractures travelled in a dorsodistal to palmaroproximal direction. Median period to screw removal was 2.0 months. Evaluation at time of screw removal revealed 98% of single stress fractures of the left front limb were healed radiographically. Median period to resume training was 2.75 months (single stress fractures); median period to race was 7.62 months. There was no statistically significant difference in earnings/start before and after surgical intervention. Of the 63 fractures treated, two recurred. There were no catastrophic failures, and no incisional infections.
Endoscopy of the navicular bursa: A new technique for the treatment of contaminated and septic bursae
Authors: WRIGHT I. M. , PHILLIPS T. J. , WALMSLEY J. P.
Published: April 2010

A technique for evaluation of the navicular bursa using a 4 mm 25° inclined view arthroscope is described. This allows examination of the palmar/plantar surface of the navicular bone, the insertions of the navicular suspensory, T and impar ligaments, the bursal synovium and the dorsal surface of the deep digital flexor tendon. The technique was used in 16 horses with punctures of the navicular bursa. Procedures facilitated by the technique were bursal lavage, removal of pannus, synovial resection and debridement of lesions on the palmar/plantar surface of the bone and in the deep digital flexor tendon. Following treatment, 10 animals were sound and returned to their pre‐injury use and 6 animals had persistent lameness; 2 of these were salvaged after neurectomy, 1 was retired for use as a broodmare and 2 were destroyed. In contrast to the ‘streetnail’ procedure, the reported technique is less invasive and post operative care is simpler. The success rate is also better. Endoscopically guided treatment therefore appears to offer an advantage in the treatment of contaminated or septic navicular bursae.
The effect of orthopaedic shoeing on the force exerted by the deep digital flexor tendon on the navicular bone in horses
Authors: WILLEMEN M. A. , SAVELBERG H. H. C. M. , BARNEVELD A.
Published: April 2010

This study quantifies both the intended effect of orthopaedic shoeing to decrease the load on the navicular bone and the eventual undesired effects on gait performance. The compressive force exerted by the deep digital flexor tendon on the navicular bone and on the quality of the trot and redistribution of forces over the flexor tendons and the suspensory ligament were studied as a function of orthopaedic shoeing in 12 sound Dutch Warmblood horses. A modified CODA‐3 gait analysis system and a force plate were used to quantify objectively the load on the lower limb. The quality of the trot was assessed using the same gait analysis system while the horses were trotting on the treadmill. The effects of shoes with heel wedges and egg‐bar shoes were compared to flat shoes and unshod feet.

When heel wedges were applied, the maximal force on the navicular bone was reduced by 24% (P<0.05) in comparison with flat shoes. Egg‐bar shoes did not reduce the force on the navicular bone, but in unshod feet this force appeared to be 14% lower (P<0.05) compared to flat shoes. Egg‐bar shoes cause the horse's trot to be slightly less animated (P<0.05), compared to flat shoes and shoes with heel wedges.

It is concluded that shoes with heel wedges reduce the force on the navicular bone as a result of a decreased moment of force at the distal interphalangeal joint in combination with a decreased angle between the deep digital flexor tendon distally and proximally of the navicular bone.

Therefore it can be expected that in horses suffering from navicular disease, heel wedges will have the expected beneficial effect on the pressure on the navicular bone, while the effect of egg‐bar shoes remains doubtful.
Post operative performance of racing Standardbreds treated arthroscopically for carpal chip fractures: 176 cases (1986–1993)
Authors: LUCAS JULIE M. , ROSS M. W. , RICHARDSON D. W.
Published: April 2010

A retrospective study of 176 Standardbred horses that had arthroscopic surgery for carpal chip fractures over a 7 year period was done in order to determine fracture location and post operative performance. Chip fractures of the proximal third carpal bone and the distal radiocarpal bone occurred with equal frequency (49.2 and 49.6% respectively), and chip fractures involving the antebrachiocarpal joint were rare. Trotters had significantly more third carpal bone lesions than radiocarpal bone lesions when compared to pacers (P = 0.0304). Seventy‐four per cent of horses made at least one start following surgery. Pacers were significantly more likely to have at least one start after surgery than were trotters (P = 0.0009). Median earnings per start significantly decreased after surgery (P = 0.0081), while median race mark significantly increased after surgery (P = 0.0100). It is concluded that the majority of Standardbreds will be useful racehorses following carpal arthroscopy; however, most earn less money per start and many race at a lower class.
Differences in second‐intention wound healing between horses and ponies: macroscopic aspects
Authors: WILMINK JACINTHA M. , STOLK P. W. TH. , VAN WEEREN P. R. , BARNEVELD A.
Published: April 2010

Second‐intention healing of deep wounds was studied in 5 horses and 5 ponies. Standardised wounds were created on the distal limbs and hind quarters. Wounds on the metatarsi extended onto the metatarsal bone; the depth of the wounds in the femoral biceps muscle was 18 mm. The wound margins were marked by tattoos. Photographs were taken at weekly intervals to determine the wound area. The relative contribution of contraction and epithelialisation to wound closure was quantified by means of the tattoos. Swelling of the limbs was measured; and regularity and aspect of the granulation tissue were semi‐quantitatively scored.

Second‐intention wound healing occurred significantly faster in ponies than in horses, and muscle wounds healed significantly faster than metatarsal wounds. These marked differences reflected the greater contribution of contraction to wound healing. Moreover, demarcation was seen earlier and a healthy granulation bed developed more rapidly in ponies, whereas in horses the granulation tissue remained irregular and purulent for longer.

Healing of the metatarsal wounds of horses differed markedly from that of all other wounds: these wounds increased to almost twice their original size in the first 2 weeks, exuberant granulation tissue was persistent, epithelialisation started later, and contraction played a minor role in wound closure. Limb swelling was greater in horses than in ponies. Periosteal new bone formation was more extensive, and was active over a longer period in the metatarsal bones of horses than of ponies.

From this study it is concluded that second‐intention healing of deep wounds occurs faster in ponies than in horses. This difference can be largely attributed to a more pronounced and faster wound contraction in ponies than in horses. Therefore, attempts to improve second‐intention wound healing in clinical practice should be directed at stimulation of wound contraction.
Ocular manifestations of equine motor neuron disease
Authors: RIIS R. C. , JACKSON C. , REBHUN W. , KATZ M. L. , LOEW E. , SUMMERS B. , CUMMINGS J. , de LAHUNTA A. , DIVERS T. , MOHAMMED H.
Published: April 2010

The characteristics of the ocular manifestations of equine motor neuron disease (EMND) are described. Forty‐two horses with histories, clinical signs and necropsies compatible with EMND were the subjects of this study.

Ophthalmoscopic lesions that varied in severity were found in 40 of 42 horses and appeared as a distinct pigmented reticulated pattern at the tapetal‐nontapetal junction or throughout the fundus, depending upon severity. The pattern colours ranged from yellow brown to black. Areas of hyperreflectivity formed mosaic patterns in the tapetal fundus. ERG B‐wave amplitudes were usually at least 50% reduced and many animals showed extinguished amplitudes. None of the horses had apparent visual impairment. Histopathologically, all 42 horses had retinal pigment epithelial (RPE) congestion with ceroid‐lipofuscin. Retinal degeneration was variable even within the eyes. Thin layer chromatography (TLC) analysis of the RPE and neural retina identified both green and orange emitting fluorescent compounds not found in normal horses. All unsupplemented horses had plasma vitamin E levels <1.0 μg/ml.

The potential significance of this report is the pathognomonic role the ocular manifestations exhibit in helping to diagnose equine motor neuron disease.

In memory of John Cummings, we dedicate this manuscript.
Structural variation of the distal condyles of the third metacarpal and third metatarsal bones in the horse
Authors: RIGGS C. M. , WHITEHOUSE G. H. , BOYDE A.
Published: April 2010

This study examined 3‐dimensional (3D) distribution of sectors with contrasting density in the equine third metacarpal (McIII) and third metatarsal (MtIII) bones with a view to explaining the aetiology of distal condylar fractures. Macroradiography and computed tomographic (CT) imaging were used in the nondestructive study of bones obtained from horses, most of which were Thoroughbreds in race training. Distal condylar regions of McIII and MtIII were also studied in microradiographs of 100 μm thick mediolateral sections cut perpendicular to the dorsal and palmar/plantar articular surfaces. Qualitative and quantitative results from all methods used (radiography, CT and microradiographic stereology) demonstrated a densification (sclerosis) of subchondral bone located in the palmar/plantar regions of the medial and lateral condyles of both McIII and MtIII. Substantial density gradients between the denser condyles and the subchondral bone of the sagittal groove were shown to equate with anatomical differences in loading intensity during locomotion. It is hypothesised that such differences in bone density results in stress concentration at the palmar/plantar aspect of the condylar grooves, which may predispose to fracture.
Pathology of the distal condyles of the third metacarpal and third metatarsal bones of the horse
Authors: RIGGS C. M. , WHITEHOUSE G. H. , BOYDE A.
Published: April 2010

This study examined material from Thoroughbred horses, the majority of which had been in race training, for evidence of pathology in the third metacarpal (McIII) and third metatarsal (MtIII) bones which might be related to the occurrence of distal condylar fractures. Whole bone samples were studied and documented by macrophotography prior to macroradiography and computed tomographic (CT) imaging. Microradiographs were made from 100 μm thick mediolateral sections cut perpendicular to the dorsal and palmar/plantar articular surfaces of distal condylar regions of McIII and MtIII. Blocks were prepared for morphological imaging using the backscattered electron mode of scanning electron microscopy (BSE SEM). Linear defects in mineralised articular cartilage and subchondral bone were found in the palmar/plantar aspects of the condylar grooves adjacent to the sagittal ridge. These were closely related to the pattern of densification of the subchondral bone and were associated with intense focal remodelling of the immediately adjacent and subjacent bone. Parasagittal fractures of the condyles originated in similar defects. A unifying hypothesis for the aetiopathogenesis of these fractures is presented.
Muscle characteristics and plasma lactate and ammonia response after racing in Standardbred trotters: relation to performance
Authors: RONÉUS N. , ESSÉN‐GUSTAVSSON B. , LINDHOLM A. , PERSSON S.
Published: April 2010

Blood samples from the jugular vein and muscle biopsies (gluteus medius) In 25 Standardbred trotters were obtained 5–10 min after racing. The biopsies were analysed for fibre type composition and enzymatic profile and blood samples for plasma lactate and ammonia concentrations.

Muscle characteristics, plasma lactate and ammonia concentrations after racing were compared with each horse's Individual performance index (IPI). The IPI is calculated annually from the Individual horse's racing performance (% placing 1, 2 or 3, total annual earnings, average earning per start, and best racing record), respectively, converted to and expressed as a percentage deviation from the average record of the same sex and age group.

The IPI values were 100–116. Plasma lactate concentrations were 15.0–42.7 mmol/l (mean 31.3 nunol/l) and ammonia concentrations 65–210 μmOl/l (mean 141 μmol/l) after racing.

Fibre type composition varied among horses (range 9–27% fortype I, 32–54% forType IIA, and 27–46% forType IIB). Fibre type composition, enzyme activities, plasma lactate and ammonia responses to racing were not correlated to IPI, Ten of the horses also performed a submaximal test on the track, consisting of 5 incremental 1000 m heats at approximate speeds of 9.1, 9.5, 10.0, 10.5, and 11.1 m/s. Immediately after each beat a blood sample was drawn from the jugular vein for plasma lactate analysis. Plasma lactate response to exercise differed between horses, but no correlation was seen with IPI.

Muscle characteristics, plasma lactate and ammonia concentrations after racing and lactate response to a submaximal track test did not correlate with current race performance expressed as IPI In a group of horses with average or better performance capacity at the time of testing. Analysis of lactate and ammonia in blood after racing is not a valuable tool to predict an individual performance index.
Hydrocortisone levels in the urine and blood of horses treated with ACTH
Authors: CALONI F. , SPOTTI M. , VILLA R. , MARIANI C. , MONTANA M. , POMPA G.
Published: April 2010

An investigation was undertaken to demonstrate whether therapeutic treatment with ACTH raises hydrocortisone (cortisol) levels in horse urine above the limit (1000 ng/ml) established by the International Conference of Racing Authorities with the aim of controlling the abuse of cortisol and ACTH in equine sports. ACTH (200 iu) was administered i.m. to 3 Thoroughbred horses; urine and blood samples were collected at intervals afterwards and analysed by an immunoenzymatic system (ELISA) and HPLC‐MS. To ascertain post exercise cortisol levels in untreated horses, 101 urine and 103 serum samples were taken from horses immediately after racing and analysed by ELISA. The peak urine level of cortisol, detected 8 h after ACTH administration, was around 600 ng/ml using either ELISA or HPLC‐MS. The peak serum cortisol concentration was found to be around 250 ng/ml by ELISA, but consistently less by HPLC‐MS. Mean cortisol levels in post race horses were 135.1 ± 72.1 ng/ml in urine and 90.1 ± 41.7 ng/ml in serum. High levels of the metabolite 20β‐dihydrocortisol in urine and the cortisol precursor 11β‐desoxycortisol in serum were found. The latter showed high cross‐reactivity with cortisol on ELISA. In our experiment, treatment with ACTH 200 iu i.m. did not raise urinary cortisol levels above the 1000 ng/ml threshold proposed by the ICRA.
Characterisation of the type and location of fractures of the third metacarpal/metatarsal condyles in 135 horses in central Kentucky (1986–1994)
Authors: ZEKAS LISA J. , BRAMLAGE L. R. , EMBERTSON R. M. , HANCE S. R.
Published: April 2010

The objective of this retrospective study was to provide a detailed description of the characteristics of condylar fractures represented in a population of 135 horses who sustained 145 fractures. Records and radiographic studies were examined. Fifty‐nine percent of the horses were male and the majority Thoroughbreds. The distribution of fractures was 37% incomplete‐nondisplaced, 30% complete‐nondisplaced and 32% complete‐displaced. The right front was more likely to sustain a complete‐displaced fracture, whereas the left front was more likely to sustain an incomplete‐nondisplaced fracture. Forelimbs (81%) and lateral condyles (85%) were more likely to be involved. Contrary to previous studies, the right forelimb was slightly more often involved than the left Fractures tended to involve the middle portion of the condyle (59%). The mean length of all fractures was 75 ± 3.8 mm. Axial fractures and medial condyle fractures tended to be longer. Fifteen percent of the fractures had definitive articular comminution. Ninety‐five percent of fractures with articular comminution were associated with complete fractures. When fractures entered the middle area of the condyle, 23% had articular comminution. Eight of the fractures spiralled, all involved forelimbs. Concurrent lesions included proximal phalanx chip fractures, sesamoid fractures, sesamoiditis, proximal phalanx fractures, ‘splint’ bone periostitis and ligamentous injuries. The complete description of the fractures in this group of horses allows us better to define the condylar fracture, compare these fractures to previous studies and establish new data for use in defining prognosis.
Effect of parturition on levels of vitamins A and E and of β‐carotene in plasma and milk of mares
Authors: SCHWEIGERT F. J. , GOTTWALD C.
Published: April 2010

The objective of this study was to investigate in mares the effect of parturition on plasma and milk levels of retinol, β‐carotene, α‐tocopherol and cholesterol over 12 weeks around parturition. In blood plasma of horses around parturition an increase of all these components was observed. This increase was most impressive in β‐carotene (P<0.05) and less pronounced for vitamin E, vitamin A and cholesterol. The magnitude of increase around parturition corresponded well with the magnitude of accumulation in colostrum; levels of β‐carotene in colostrum were 65 times higher compared to mature milk while vitamin A, vitamin E and cholesterol were only 3 to 8 times higher. β‐carotene concentrations in colostrum were positively correlated with corresponding plasma levels (r = 0.9; P<0.001). Reasons for the increase in plasma β‐carotene around parturition may include an improved absorption of carotene and/or reduced conversion into vitamin A as well as mobilisation from tissue storages or a reduced uptake in tissues other than the mammary gland. In conclusion, the results may point to possible component‐ and species‐specific differences involved in the transfer of fat‐soluble vitamins, β‐carotene and cholesterol from blood plasma into colostrum.
The characteristics of intestinal injury peripheral to strangulating obstruction lesions in the equine small intestine
Authors: GERARD M. P. , BLIKSLAGER A. T. , ROBERTS M. C. , TATE L. P. , ARGENZIO R. A.
Published: April 2010

Recent studies suggest that horses requiring surgical correction of strangulating intestinal obstruction may develop post operative complications as a result of ischaemia/ reperfusion injury. Therefore, the mucosal and serosal margins of resected small intestine from 9 horses with small intestinal strangulating lesions were examined for evidence of ischaemia/reperfusion injury. Severe mucosal injury and marked elevations in myeloperoxidase activity were detected at ileal resection margins (n = 4), whereas the mucosa from proximal jejunal (n = 9) and distal jejunal (n = 5) resection margins was normal. However, the serosa from jejunal resection margins had evidence of haemorrhage and oedema, and the proximal jejunal serosa had significantly increased numbers of neutrophils. Histological injury in ileal stumps is indicative of the inability fully to resect the ileum in horses with distal small intestinal strangulations. One of 4 horses subjected to ileal resection was subjected to euthanasia and found to have a necrotic ileal stump. Evidence of serosal injury and neutrophil infiltration in the proximal jejunal resection margins may predispose horses to post operative adhesions. Four of 8 horses discharged from the hospital suffered from recurrent colic in the post operative period.
Equine dental disease Part 1: A long‐term study of 400 cases: disorders of incisor, canine and first premolar teeth
Authors: DIXON P. M. , TREMAINE W. H. , PICKLES KIRSTIE , KUHNS LORNA , HAWE CARLYN , McCANN JACQUI , McGORUM B. , RAILTON D. I. , BRAMMER STEPHANIE
Published: April 2010

A review of 400 horses referred because of dental disorders showed 44 cases to suffer from primary disorders of their incisors and 11 from canine or 1st premolar teeth disorders. The remaining 345 horses suffered from primary disorders of the cheek teeth. Disorders of incisors included traumatic damage to teeth and their supporting bones, retained deciduous, displaced and supernumerary incisors; brachygnathia and abnormalities of wear, with most of the latter disorders being secondary to primary disorders of the cheek teeth Only 3 cases of apical infection of incisors were recognised. Most cases of fractured incisors responded well to conservative therapy. Retained deciduous incisors were extracted, but most cases with supernumerary and displaced incisors, or brachygnathia were treated conservatively. Most disorders of the canine and 1st premolar were developmental displacements that caused bitting problems (abnormalities of head movement associated with the bit), and these cases responded well to extraction of the displaced teeth.
Cardiovascular demands of competition on low‐goal (non‐elite) polo ponies
Authors: MARLIN D. J. , ALLEN J. C. R.
Published: April 2010

Knowledge of the competitive demands of different sports or activities is important for designing appropriate training programmes to ensure that animals reach a sufficient level of fitness to reduce the risk of overexertion and injury or illness and to achieve the best possible performance in relation to an individual's genetic potential. Whilst the physiological demands of many equestrian sports have been described, to the best of our knowledge the cardiovascular demands of polo have not. The aims of the present study were therefore to record heart rate during and after competitive polo games in a group of low‐goal (non‐elite) polo ponies in order to describe the absolute heart rates during play, the relationship of these heart rates to maximal heart rate and the characteristics of a typical chukka in terms of effort. Six low‐goal polo ponies were studied during a total of 59 chukkas. Heart rate was monitored continuously before, during and after competition using a commercial heart rate monitor. Maximal heart rate was determined with field and treadmill incremental exercise tests and used to express work intensity in terms of time during play that each ponies heart rate was less than 75% HRmax, between 75 and 90% HRmaxand greater than 90% HRmax. Mean maximum heart rate was not different during play or during field and treadmill exercise tests; 215 ± 7 (mean ± s.d.), 211 ± 7 and 213 ± 2 beats/min, respectively (P>0.05). Mean heart rate for all ponies over all chukkas was 166 ± 6 beats/min with a mean chukka duration of 611 ± 18 s. Of this time, 44 ± 7% of the time was spent below 75% HRmax, 39 ± 8% between 75 and 90% HRmaxand 17 ± 8% of time above 90% HRmax. When only one chukka had been played, there was a good correlation between mean heart rate during play and 3 min recovery heart rate (r = 0.63, P<0.001). Based on these observations, it is proposed that low‐goal polo places moderate to high stress on the cardiovascular system.
Disposition and tolerance of suxibuzone in horses
Authors: JARAIZ M. V. , RODRIGUEZ C. , ANDRES M. D. SAN , GONZALEZ F. , ANDRES M. I. SAN
Published: April 2010

Suxibuzone (SBZ), a nonsteroidal anti‐inflammatory drug, was administered to 6 horses at a dose rate of 7.5 mg/kg bwt by intravenous (i.v.) route. Plasma and synovial fluid concentrations of suxibuzone and its main active metabolites, phenylbutazone (PBZ) and oxyphenbutazone (OPBZ), were measured simultaneously by a sensitive and specific high‐performance liquid chromatographic method. The pharmacokinetic parameters were determined by noncompartmental analysis. Plasma SBZ concentrations rapidly decreased and were not detectable beyond 20 min after treatment. The parent drug was not detected in any synovial fluid samples. Average maximum plasma concentrations of PBZ (16.43 μg/ml) and OPBZ (2.37 μg/ml) were attained at 0.76 and 7.17 h, respectively. The mean residence time (MRT) of PBZ was 6.96 h in plasma. Oxyphenbutazone plasma concentrations were below those reached by phenylbutazone during the first 12 h after suxibuzone administration, even though its values were detectable for at least 24 h (MRT = 10.65 h). Plasma concentrations of PBZ and OPBZ exceeding EC50and IC50of TXB2and PGE2were reached by at least 12 h. Synovial fluid concentrations of PBZ and OPBZ were 2.87 ± 0.37 μg/ml and 0.97 ± 0.08 ug/ml at 9 h after suxibuzone administration and exceeded IC50of PGE2for at least this time. In the present study, suxibuzone was well tolerated following i.v. injection.
Supporting forelimb lameness: clinical judgement vs. computerised symmetry measurement
Authors: PEHAM C. , LICKA THERESIA , GIRTLER D. , SCHEIDL M.
Published: April 2010

The aim of this study was to compare supporting forelimb lameness determined by a motion analysis system with the subjective grading of a trained equine orthopaedic surgeon. Trotting on a treadmill, 29 individuals with a supporting forelimb lameness were measured with the SELSPOT II system and judged by the clinician. The vertical motion of the head was measured, analysed using Fourier transform, and the percentages of symmetry determined. The veterinarian evaluated the lameness and graded it according to a clinical routine. Veterinarian and system for motion analysis assigned the lameness to the same leg in all cases, but the grading of the lameness differed in 6 out of 29 cases. The results of this study indicate that motion analysis can be used as an informative tool supporting the subjective veterinary judgement.
Factors involved in the prognosis of equine laminitis in the UK
Authors: CRIPPS P. J. , EUSTACE R. A.
Published: April 2010

The significance of clinical and radiological parameters as prognostic indicators for laminitis, ‘founder’ and ‘sinking syndrome’ was studied using case records of 216 horses and ponies. Five animals were destroyed without treatment and were not included in the results of the study. One hundred and sixty‐two (77%) animals returned to athletic soundness; 7 animals (3%) did not regain full athletic function, 42 animals (20%) died or were destroyed. Cases were assigned to 4 groups on the basis of initial clinical examination alone. These groups were laminitis, acute founder, ‘sinker’ and chronic founder. This grouping was found in itself to be the most important prognostic parameter which was studied. Stepwise regression analysis of the data from animals by group indicated that the radiological measurement of founder distance, was the most significant radiological prognostic measurement for acute founder cases. Less significant prognostic parameters were the severity of lameness, rotation angles, the presence of solar prolapse, and the number of feet affected. The height of the animal at the withers was not significantly related to outcome. The prognosis for horses was not significantly different from that for ponies.
A serological and clinical follow‐up in horses with confirmed equine granulocytic ehrlichiosis
Authors: ARTURSSON KARIN , GUNNARSSON A. , WIKSTRÖM ULLA‐BRITT , ENGVALL EVA OLSSON
Published: April 2010

For diagnosis of equine granulocytic ehrlichiosis (EGE) serological testing of antibodies toEhrlichia equiis frequently used. An elevated antibody level is often misinterpreted as confirmative of active infection and results in treatment with antibiotics. If only seropositivity is considered as the diagnostic criterium, many horses showing convalescence titres will be treated. This study was undertaken to obtain information about the kinetics of antibodies during the course of infection and, for this purpose, 45 horses with clinical signs of EGE and confirmed ehrlichiaemia were monitored serologically and clinically over time. For a correct handling of cases with suspected EGE, the following results should be helpful: (i) 44% of the horses in the acute ehrlichiaemic stage were found to be serologically positive toE. equi;(ii) all horses showed a rapid increase in antibody titre, reaching maximum value within a month after the ehrlichiaemic stage; (iii) when 8 months had passed, titres had decreased, but 18 of 24 examined horses were still serologically positive; (iv) after 12–15 months most of the horses (n = 10) were serologically negative; and (v) the period required for complete clinical recovery varied from one day up to 6 months after antibiotic treatment.
The role of subchondral bone in joint disease: a review
Authors: KAWCAK C. E. , McILWRAITH C. W. , NORRDIN R. W. , PARK R. D. , JAMES S. P.
Published: April 2010

Subchondral bone plays a role in the pathogenesis of osteochondral damage and osteoarthritis in horses and humans. Osteochondral fragmentation and fracture, subchondral bone necrosis and osteoarthritis are common diseases in athletic horses, and subchondral bone is now thought to play an integral role in the pathogenesis of these diseases. There have been numerous research efforts focused on articular cartilage damage and its pathogenesis, yet comparatively little effort focused on subchondral bone pathology or the coordinated disease states of the osteochondral tissues. The purpose of this report is to review the current understanding of osteochondral disease in all species and its application to equine research and practice. It can be concluded from this review that our current understanding of osteochondral disease is based on clinical and pathological sources; and that the lack of information about joint tissue adaptation and disease has hampered objective studies of osteochondral tissues.
Upregulation of mRNA of interleukin‐1 and ‐6 in subchondral cystic lesions of four horses
Authors: svon RECHENBERG B. , LEUTENEGGER C. , ZLINSKY K. , McILWRAITH C. W. , AKENS M. K. , AUER J. A.
Published: April 2010

This study investigated the potential association of interleukin‐1β (IL‐1β) and interleukin‐6 (IL‐6) in subchondral cystic lesions (SCL) in horses. With the technique of in situ hybridisation in paraffin sections of fibrous tissue of SCL and quantitative real‐time PCR in fresh frozen fibrous tissue and undecalcified bone sections of SCL embedded in acrylic resin, upregulation of mRNA of both cytokines could be demonstrated. mRNA of IL‐1β was upregulated at the periphery of the cystic lesion adjacent to normal bone, whereas IL‐6 mRNA was upregulated within the fibrous tissue found within the centre of the SCL. It was concluded that both cytokines are associated in pathological bone resorption observed in SCL and, in combination with increased production of prostaglandin E2, may be responsible for the slow healing, maintenance or further expansion of the cystic lesions.
Neurological disease associated with EHV‐1‐infection in a riding school: clinical and virological characteristics
Authors: van MAANEN C. , van OLDRUITENBORGH‐OOSTERBAAN M. M. SLOET , DAMEN E. A. , DERKSEN A. G. P.
Published: April 2010

An outbreak of neurological disease caused by EHV‐1 infection is described with emphasis on diagnosis and prognosis for recumbent horses. In April 1995, an outbreak of the neurological form of Equine herpesvirustype 1(EHV ‐ 1) occurred in a well‐managed riding school with 41 horses: 34 horses showed a temperature spike and 20 some degree of neurological signs, of which 10 were nursed intensively in the indoor arena of the riding school for 3 to 20 days, 8 having to be maintained in slings for 2–18 days, while 9 needed bladder catheterisation b.i.d. for 2–16 days. Within the first 3 days, one horse was subjected to euthanasia and another horse died.Postmortemexamination revealed a mild vasculitis with perivascular mononuclear cuffing and axonal degeneration in the central nervous system.

Clinical diagnosis was confirmed by serology and virology: 28 horses seroconverted in one or more tests during the outbreak, whereas 12 had already high CF and SN titres in the first sample, suggestive of recent infection. Virus was isolated from nasal swabs of 4 horses, and identified as EHV‐1 with type‐specific monoclonal antibodies. Restriction enzyme analysis revealed that the EHV‐1 strains from this outbrék belonged to genome type EHV‐1.IP. The electropherotypes were identical to those from another, epidemiologically unrelated, outbreak of neurological disease 2 months earlier. The timing of the temperature spikes and seroconversions indicated that the infection was probably introduced by a horse purchased 3 weeks before neurological signs occurred.

At follow‐up one year later, the 10 horses that showed mild neurological signs had recovered completely. Of the 8 horses that survived intensive care, 3 had returned to around their former performance level (2 of which had been in slings), while the other 5 had become pasture‐sound. At follow‐up 4 years later, all pasture‐sound horses had been subjected to euthanasia because of persistent mild ataxia and incontinence. In conclusion, the prognosis for recumbent horses due to EHV‐1 infection is grave. For virological diagnosis, extensive and strategic sampling of febrile in‐contact horses is required, and the EHV‐1‐specific glycoprotein G (gG) ELISA is a valuable tool for specific serological diagnosis of EHV‐1 infection causing neurological disease.
Evaluation of Applying Low Calorific Fuel as Reburn Fuel in an Opposed Wall Fired Boiler
Authors: Xu Guang , Zhou Wei , Swanson Larry W. , Moyeda David K. , Nguyen Quang
Published: April 2010

The alternative fuels, such as biomass, municipal wastes, and underground coal gasification gas, become attractive to the power plants as renewable energy sources or economical fuels. However, the alternative fuels usually have much lower heating value and different chemical compositions from those of coal and natural gas. Firing these alternative fuels in the boilers that are originally designed for coal firing or natural gas firing may cause unexpected boiler operating issues and/or thermal performance degradation. A careful evaluation study is often required prior to implementation. This paper presents the results of a study that evaluated the feasibility of using an underground coal gasification gas as a reburn fuel. The evaluation was done on Eskom’s Majuba Unit 5, a 710 MWe opposed wall-fired boiler, located in South Africa. The study utilized heat transfer analysis and computational fluid dynamics models to (1) evaluate the impacts of firing low calorific fuel on boiler efficiency and the boiler auxiliary system performance, (2) develop a conceptual gas reburn injection system, and (3) evaluate the impacts of gas reburn on the boiler thermal performance and boiler NOx emissions. The results indicate that the underground coal gasification gas can be an effective reburn fuel for the Majuba boiler with upgrades on the auxiliary systems.
Numerical Simulation of Thermal Stress for a Liquid-Cooled Exhaust Manifold
Authors: Fu Dong , Huang Dui , Juma Ahmed , Schreiber Curtis M. , Wang Xiuling , Zhou Chenn Q.
Published: April 2010

Liquid-cooled exhaust manifolds are widely used in turbocharged diesel engines. The large temperature gradient in the overall manifold can cause remarkable thermal stress. The objective of the project is to optimize the operation condition and modify the current design in order to prevent high thermal stress and to extend the lifespan of the manifold. To achieve the objective, the combination between computational fluid dynamics (CFD) with finite element (FE) is introduced. First, CFD analysis is conducted to obtain temperature distribution, providing conditions of the thermomechanical loading on the FE mesh. Next, FE analysis is carried out to determine the thermal stress. The interpolation of the temperature data from CFD to FE is done by binary space partitioning tree algorithm. To accurately quantify the thermal stress, nonlinear material behavior is considered. Based on stresses and strains, the fatigue life can be estimated. The CFD results are compared with that of the number of transfer units’ method and are further verified with industrial experiment data. All these comparisons indicate that the present investigation reasonably predicts the thermal stress behavior. Based on the results, recommendations are given to optimize the manifold design and operation.
The Onset of Collective Behavior in Social Amoebae
Authors: Gregor Thomas , Fujimoto Koichi , Masaki Noritaka , Sawai Satoshi
Published: April 2010

All Together Now

In the social amoeba
Dictyostelium discoideum
, periodic synthesis and release of cyclic AMP (cAMP) guides the cellular aggregation required to form fruiting bodies. It has been unclear whether the initiation of this behavior is owing to synchronization of autonomously oscillating cells or whether individual cells remain nonoscillatory unless the entire population becomes oscillatory.

Gregor
et al.

(p.
1021
, published online 22 April; see the Perspective by

Prindle and Hasty

) used live-cell imaging to show that cAMP pulses originate from a specific location in space and that individual cells move in and out of these signaling centers. The observations suggest that oscillations do not originate from autonomous activities of specialized cells. However, individual cells do display stochastic cAMP-pulsing below a threshold external concentration of cAMP, and the generation of synchronized oscillations could only be modeled accurately when this random pulsing was taken into account.
Neural Crest–Derived Pericytes Promote Egress of Mature Thymocytes at the Corticomedullary Junction
Authors: Zachariah Marcus A. , Cyster Jason G.
Published: April 2010

Thymocyte Egress

A critical step during the development of the immune system is the egress of developing T lymphocytes, or thymocytes, from the thymus to peripheral organs, where they can defend against infectious microorganisms. Egress requires detection of the lipid mediator, sphingosine-1-phosphate (S1P), by thymocytes, but whether S1P detection is sufficient for egress, the source of S1P and the location where T lymphocytes exit the thymus are unknown.
Zachariah and Cyster
(p.
1129
, published online 22 April) found that selective expression of a transgene for the S1P receptor-1 in mouse thymocytes was sufficient for thymocyte egress. Thymocyte egress occurred at corticomedullary junctions via blood vessels, rather than via lymphatics. Pericytes, neural crest-derived cells, which ensheath blood vessels, provided the S1P for exiting thymocytes.