bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of equine cutaneous neoplasia by radiotherapy using iridium 192 linear sources
Authors: WYN‐JONES G.
Published: April 2010

The treatment of equine cutaneous tumours by conventional or cryosurgical techniques can be limited where the position of the tumour makes radical excision or freezing impractical or dangerous. Radiotherapy provides an effective and practical alternative. The use of iridium pins with guide needles allows accurate positioning of sources and uniform radiation fields to be achieved. The subsequent removal of the pins reduces the period of incapacity and reduces the radiation risk when compared to permanently implanted sources. Twenty‐seven tumours on 26 horses were treated by this method with a 100 per cent success rate after a single irradiation. The technique of implantation is described and the criteria used to select cases and to assess the efficacy of this treatment are discussed.

Parfois l'emplacement d'une tumeur est telle que les techniques conventionnelles de traitement ou la cryochirurgie sont impraticables ou dangereuses. La radiothérapie procure une alternative commode et efficace. Les aiguilles d'iridium glissées dans des aiguilles guides sont faciles à mettre en place et fournissent une irradiation uniforme. Leur retrait réduit la durée d'incapacité et diminue le risque d'irradiations. Vingt‐sept tumeurs ont été ainsi traitées sur 26 chevaux avec 100 pour cent de réussite après une seule irradiation. La technique d'implantation est décrite, ainsi que les critères de sélection des cas cliniques et d'appréciation de l'efficacité du traitement.

Die Behandlungsmöglichkeiten von Hauttumoren des Pferdes durch Konventionell‐chirurgische oder cryo‐chirurgische Techniken können dann eingeschränkt sein, wenn eine radikale Excision oder das Gefrieren nicht durchführbar oder wegen der Lage des Tumors gefährlich wäre. Die Radiotherapie stellt eine wirksame und praktische Alternative dar. Iridium‐Stifte mit Führnadeln erlauben ein exaktes Plazieren der Strahlungsquelle und gewährleisten uniforme Strahlungsfelder. Das Entfernen der Stifte reduziert die Periode der Ruhigstellung und selbstverständlich auch die Strahlungsrisiken, verglichen mit permanenten Implantaten. Sieben und zwanzig Tumoren von 26 Pferden wurden derart behandelt, wobei der Erfolg bei 100 Prozent nach einmaliger Bestrahlung lag. Die Technik der Implantation wird beschrieben; die Kriterien für die Auswahl der Fälle und für die Beurteilung des Behandlungserfolges werden diskutiert.
Experiences in diagnostic and surgical arthroscopy in the horse
Authors: McILWRAITH C. W.
Published: April 2010

This paper reviews the current status of diagnostic and surgical arthroscopy in the horse. Arthroscopy has been used as a diagnostic aid since 1974 and is useful for evaluation of abnormalities in synovial membrane and articular cartilage. Surgical arthroscopy is a more recent advance that has replaced conventional arthrotomy in 90 per cent of the author's cases. Clinical conditions currently being treated using arthroscopic techniques rather than arthrotomy include all chip fractures in the carpus, chip fractures of the first phalanx, chronic proliferative synovitis in the fetlock and osteochondritis dissecans of the femoropatellar and tibiotarsal joints. The equipment requirements and basic techniques are reviewed. Convalescent time following surgery is decreased and the cosmetic appearance improved compared to arthrotomy. Considerable experience is required for competent surgery which, in turn, is necessary for this method to have advantage over previous conventional techniques.
Urolithiasis in the horse — A review of 13 cases
Authors: HOLT P. E. , PEARSON H.
Published: April 2010

The presenting signs, treatment and postoperative progress of 13 horses with vesical and urethral calculi are reviewed. Single, discrete stones were present in 10 animals in which the results of treatment were generally good. In three horses with sabulous cystic deposits, urolithiasis was associated with bladder paralysis and the response to treatment was poor.
Survey of positive results from racecourse antidoping samples received at Racecourse Security Services' Laboratories
Authors: MOSS M. S. , HAYWOOD P. E.
Published: April 2010

A review of positive Jockey Club “dope tests” during the 12 years from 1970 to 1981 inclusive is presented and a comparison made with certain overseas racing authorities for varying periods between 1975 and 1981. Urinary pH of post race urine samples is predominantly acidic (although varying in a significant manner throughout the year) and thus favours excretion of the generally more potent basic drugs. The proportion of positive results was about the same in winners and non‐winners, ie, one in 400 horses sampled. Drugs found fell mainly into four categories: methylxanthines; non‐steroidal anti‐inflammatories; local anaesthetics and anabolic steroids. Evidence indicates that deliberate “doping” is relatively rare. This contrasts with certain overseas authorities where evidence of “doping” is usually much stronger and occurs more frequently (about one in five; one in 50 and one in 240 in the three authorities cited) and where sympathomimetic amines are relatively frequent. Evidence of the deterrent effect of routine testing is presented.
Preferential landing and engorging sites of Culicoides species landing on a horse in Ireland
Authors: TOWNLEY P. , BAKER K. P. , QUINN P. J.
Published: April 2010

An investigation of the landing and engorging sites of midges on a bait horse was made in Ireland as part of a project examining the aetiology of sweet itch. Ten species were recovered, seven of which engorged. Culicoides obsoletus and C dewulfi were the most commonly represented, accounting for 89.9 per cent of midges landing and 90.5 per cent of midges engorging. Only 4.69 per cent of midges attracted to the bait were C pulicaris. Overall, the preferential landing sites for midges were along the mane and lower leg regions. Few culicoides were attracted to the head, front and underside of the animal. Two species, C punctatus and C nubeculosus, fed exclusively at the predilection sites of sweet itch but in very small numbers. C pulicaris fed predominantly at these sites also and represented 5.08 per cent of the engorging catch.

Of 10,178 midges attracted to the bait, 4097 (40.3 per cent) engorged; the majority of the species taking full blood meals fed on the mane and lower legs. Midges biting in other areas tended to have smaller meals.

Areas along the dorsal midline of the body are predilection sites for sweet itch lesions and are preferential engorging sites also. However, considerable engorgement occurred on the lower legs where sweet itch lesions do not occur.
Three cases of ruptured mitral valve chordae in the horse
Authors: HOLMES J. R. , MILLER P. J.
Published: April 2010

The paper describes clinical observations in three horses with ruptured mitral valve chordae. Horses with ruptured mitral valve chordae may have a history of sudden onset of acute distress with predominantly respiratory symptoms. On auscultation there will be a widespread pansystolic murmur with an extension of the area of cardiac auscultation. The third heart sound may be very pronounced and unduly prolonged, associated with high volume flow during early ventricular filling in diastole. However, these sounds are not specific for chordal rupture — they are typical of severe mitral regurgitation. The electrocardiogram may show predominantly backward spatial vectors during ventricular depolarisation. The condition gives rise to left ventricular volume overload and pulmonary hypertension would be expected in horses showing signs of cardiovascular disturbance or those recently affected. Care is necessary during post mortem examination to avoid cutting through the mitral valve before a proper assessment has been made of the chordal insertions.
The acute inflammatory process, arachidonic acid metabolism and the mode of action of anti‐inflammatory drugs
Authors: HIGGINS A. J. , LEES P.
Published: April 2010

Arachidonic acid is a polyunsaturated fatty acid covalently bound in esterified form in the cell membranes of most body cells. Following irritation or injury, arachidonic acid is released and oxygenated by enzyme systems leading to the formation of an important group of inflammatory mediators, the eicosanoids. It is now recognised that eicosanoid release is fundamental to the inflammatory process. For example, the prostaglandins and other prostanoids, products of the cyclo‐oxygenase enzyme pathway, have potent inflammatory properties and prostaglandin E2is readily detectable in equine acute inflammatory exudates. The administration of nonsteroidal anti‐inflammatory drugs results in inhibition of prostaglandin synthesis and this explains the mode of action of agents such as phenylbutazone and flunixin. Lipoxygenase enzymes metabolise arachidonic acid to a group of non‐cyclised eicosanoids, the leukotrienes, some of which are also important inflammatory mediators. They are probably of particular importance in leucocyte‐mediated aspects of chronic inflammation. Currently available non‐steroidal antiinflammatory drugs, however, do not inhibit lipoxygenase activity. In the light of recent evidence, the inflammatory process is re‐examined and the important emerging roles of both cyclo‐oxygenase and lipoxygenase derived eicosanoids are explored. The mode of action of current and future antiinflammatory drugs offered to the equine clinician can be explained by their interference with arachidonic acid metabolism.
Fibre types, enzyme activities and substrate utilisation in skeletal muscles of horses competing in endurance rides
Authors: ESSÉN‐GUSTAVSSON BIRGITTA , KARLSTRÖM KRISHNA , LINDHOLM A.
Published: April 2010

Venous blood samples and middle gluteal muscle biopsies were obtained from 21 horses taking part in 100 km or 50 km endurance rides. Group A consisted of seven horses competing over 100 km (four horses completed the ride), Group B consisted of the six horses that were among the 10 best over 50 km while the other eight horses of Group C completed 50 km at a slower speed. Blood lactate, glycerol and creatine kinase increased in all groups while aspartate aminotransferase levels were higher only in Group A. No change was found in blood glucose in Groups B and C while horses in Group A had lower levels after the ride. Neither fibre composition, fibre areas nor enzyme activities differed between the groups. Intramuscular glycogen content was similar before the ride in all groups. After the ride glycogen had decreased only half as much in Group C as compared to Groups A and B. Group C had a higher intramuscular triglyceride content at rest than Group B. The greatest decrease in triglyceride content after the ride was found in Group C. In Groups A and B many Type I, IIA and IIB fibres were glycogen depleted after the ride while in Group C mainly Type I and some Type IIA fibres were depleted. The results of this study show that intramuscular carbohydrate and lipid stores are both important fuels during endurance rides.
Preliminary studies of mammary secretions in the mare to assess foetal readiness for birth
Authors: OUSEY JENNIFER C. , DUDAN FRANCOISE , ROSSDALE P. D.
Published: April 2010

The status of the mare and foetus in relation to readiness for birth was assessed by measurement of the electrolytes sodium, potassium and calcium in mammary secretions pre‐partum.

Sixteen Thoroughbred mares were allowed to foal spontaneously and the ionic status of their mammary secretions was measured over three to five weeks pre‐partum. From these measurements, a scoring system was developed where an ionic score of 35 points or more suggested that the mare was within 24 h of foaling. On the basis of this ionic score, 10 pony mares were induced with either oxytocin or fluprostenol and assessment of foal maturity was made by physical, behavioural and physiological criteria.

Eight pony mares, induced when the ionic score was 35 points or more, delivered full term foals; two mares were induced when their scores were 30 and 20 points and delivered a full term and slightly immature foal respectively.

These results suggest that foetal maturity may be related to electrolyte concentrations in mammary secretions and that an ionic score of 35 points or more may indicate that induction would be successful in terms of maturity of the newborn foal.
Effects of fluprostenol administration in mares during late pregnancy
Authors: OUSEY JENNIFER C. , DUDAN FRANCOISE E. , ROSSDALE P. D. , SILVER MARIAN
Published: April 2010

The effectiveness of the prostaglandin F analogue fluprostenol in inducing labour in the mare was examined by giving sequential injections over the last 50 days of gestation. The behavioural and endocrine changes elicited by the drug in pregnant and non‐pregnant animals and in foals were also studied. Fluprostenol (250 or 500 μg intramuscularly) failed to induce labour before 320 days gestation; thereafter its effect was capricious. Twelve mares foaled 1 to 36 h after the last test; eight delivered normal, viable, apparently ‘term’ foals and four produced stillborn/premature animals. Eight of the deliveries (five term and three pre‐term foals) could be ascribed to the action of fluprostenol because they occurred 1 to 6 h after its administration, at a time when spontaneous foaling would have been unlikely. The other four mares foaled between 12 and 36 h after the fluprostenol injection and it is therefore doubtful whether there was a causal relationship between the two events. In the mares which delivered viable foals the pre‐partum milk samples were characteristic of full term samples with respect to calcium, sodium and potassium. Those which delivered premature/stillborn foals had low calcium and a high sodium/potassium ratio in the pre‐partum milk. Behavioural changes (sweating, increased respiration, defaecation etc), which varied in intensity between tests and individuals, were seen in all three groups of animals following the administration of fluprostenol. These changes were accompanied by rises in plasma cortisol and adrenocorticotrophic hormone concentration during the 2 h sampling period, suggesting a centrally mediated response to the drug. In the pregnant mares no significant changes in either uterine or peripheral plasma levels of prostaglandin metabolite were detected following fluprostenol injection, indicating that the analogue did not stimulate endogenous prostaglandin metabolism under these conditions. The present findings show that fluprostenol has inducing properties but its safety and efficacy are questionable and its action requires further evaluation.
Studies on equine prematurity 1: Methodology
Authors: ROSSDALE P. D. , OUSEY JENNIFER C. , DUDAN FRANCOISE E. , LEADON D. P. , CASH R. S. G. , REDDY R. , SILVER MARIAN , FOWDEN ABIGAIL , PIPKIN FIONA BROUGHTON , JEFFCOTT L. B.
Published: April 2010

This paper describes the general management of mares and foals during the perinatal period and the methodology used in a collaborative research project on equine prematurity. Sixteen mares with dated pregnancies delivered 45 foals over three breeding seasons (1981 to 1983). In the majority, parturition was induced with oxytocin and/or fluprostenol; the remainder were allowed to foal spontaneously. Pre‐colostral milk analysis provided a means of assessing the pre‐foaling status of the mare. All were observed and monitored before, during and after parturition and the sampling protocol for both mare and newborn foal is discussed in detail. The foals were assessed for their degree of maturity at birth using behavioural, haematological, acid‐base status and other criteria; they were then assigned to groups for further study and tests.
Studies on equine prematurity 6: Guidelines for assessment of foal maturity
Authors: ROSSDALE P. D. , OUSEY JENNIFER C. , SILVER MARIAN , FOWDEN ABIGAIL
Published: April 2010

This paper describes criteria used to assess maturity of the newborn foal and their clinical application to field cases of prematurity and dysmaturity. Premature and mature foals may be clearly distinguished by their behavioural and physical characteristics. Measurement of haematological parameters (mean cell volume, total white cell and differential counts), pancreatic β cell activity (plasma glucose and insulin levels), adrenocortical‐medullary function (plasma cortisol, adrenocorticotrophic hormone and catecholamines) and the renin‐angiotensin system (plasma renin substrate concentrations) were found useful in evaluating the status of the newborn foal. Confirmation of the initial diagnosis can be made by response to various challenge tests eg, glucose tolerance test, short acting synthetic adrenocorticotrophic hormone (ACTH1–24) and frusemide. In the present investigation a small number of individuals appeared to be intermediate in maturity to the other two groups, indicating that a third state of maturity may be identified. The clinical implications of this work suggest that cortisol replacement therapy and administration of long acting synthetic ACTH1–24 may be of benefit.
Developments in management of the newborn foal in respiratory distress 2: Treatment
Authors: WEBB A. I. , COONS T. J. , KOTERBA ANNE M. , KOSCH P. C.
Published: April 2010

New developments in therapy for foals in respiratory distress are discussed. Therapy is based on preservation of the foal's life by maintenance of a patent airway, resuscitation with fluids and warmth, provision of humidified oxygen to raise the fractional concentration of inspired oxygen sufficient to avoid hypoxia and provision of ventilatory support when hypercapnia becomes critical. Ventilatory support described includes assisted and controlled ventilation, positive end expiratory pressure, continuous positive airway pressure and intermittent mandatory ventilation. The aims of these techniques are discussed together with their associated indications, disadvantages and complications. Secondary therapy includes coupage, airway hygiene, drug therapy and stress management. Knowledge of equine neonatology is limited in comparison with human neonatology. More information in basic physiology and pharmacology relating to equine neonatology is needed and the efficacy of various modes of therapy must be evaluated.
Respiratory studies in foals from birth to seven days old
Authors: STEWART JENNIFER H. , ROSE R. J. , BARKO ANNE M.
Published: April 2010

Respiratory measurements and blood‐gas and acid‐base values are reported in nine term induced foals. Measurements were performed at 2, 15, 30 and 60 mins, 4, 12, 24 and 48 h, and four and seven days after birth. Minute respiratory volume was significantly lower at birth than values from 12 h old. Tidal volume peaked at 60 mins old, while respiration rate decreased significantly at 15 mins after birth. Oxygen consumption was high at birth and decreased to its lowest values at 24 and 48 h. The respiratory exchange ratio and ventilatory equivalent showed few significant changes to seven days, as did the minute alveolar ventilation and physiological deadspace.

The blood‐gas and acid‐base values indicated that the foals rapidly establish adequate pulmonary ventilation within minutes of birth, and that those values changed little from 12 h to seven days after birth. Body position had a significant effect on arterial oxygen tension with Pao2 values in lateral recumbency being, on average, 14 mmHg lower than when the foals were standing.
Echocardiography in foals from birth to three months old
Authors: STEWART JENNIFER H. , ROSE R. J. , BARKO ANNE M.
Published: April 2010

Simultaneous echocardiograms, phonocardiograms and electrocardiograms were performed on 16 foals at the following times after birth: 15 mins, 60 mins, 2, 4, 12, 24, 48 h, four, seven, 14 days and four, eight and 12 weeks. Positive correlations were found between both age and body weight and the following measurements: left ventricular end‐diastolic dimension, right ventricular end‐diastolic dimension, left atrial dimension and aortic root dimension, posterior left ventricular wall thickness and interventricular septal thickness. Heart rate was negatively correlated with left ventricular electromechanical systole, ejection time and isovolumic contraction time. Means and standard deviations are presented for 29 echocar‐diographic parameters and the results are discussed against the background of the transitional neonatal circulation.
Clinical and clinicopathological characteristics of the septicaemic neonatal foal: Review of 38 cases
Authors: KOTERBA ANNE M. , BREWER BARBARA D. , TARPLEE F. A.
Published: April 2010

In an effort to identify improved methods for diagnosis of infection in the neonatal foal, clinical records from 38 septicaemic foals of less than one week of age were examined for trends in history, physical examination and clinicopathological findings. The survival rate of septicaemic foals, 26 per cent, was markedly less than the rate for all other foal admissions. Blood cultures were valuable in diagnosis and treatment of septicaemia and identified a preponderance of Gram‐negative infection. Zinc sulphate turbidity test results were abnormally low in all septicaemic foals tested. The clinical course was often distinguished by severe complications and multiple organ dysfunction, leading to death. Conditions present in the mare pre‐partum resulted in weak or diseased foals; bacterial placentitis, vaginal discharge and premature lactation were most common. There was no single diagnostic criterion of the septicaemic foal. Fever was not a consistent finding. The most useful white blood cell parameters were neutropenia, the presence of band neutrophils (greater than 0.2 × 109/litre) and toxic changes in the neutrophil population. Hypoglycaemia, metabolic acidosis and hypoxaemia were also common findings.
Radiological investigations of osteochondrosis dissecans in Standardbred Trotters and Swedish Warmblood horses
Authors: HOPPE F.
Published: April 2010

A total of 106 Standardbred Trotters and 27 Swedish Warmblood horses, with a radiological diagnosis of osteochondrosis dissecans, were studied over a six year period. The majority were young horses. No statistical difference in frequency between the sexes was demonstrated. In both breeds osteochondrosis was most common in the hock joints, the site of predilection being the distal dorsal tip of the intermediate tibial ridge. On radiographs the lesions of the hock joints were graded on a scale from 0 to 5 according to size, number and localisation of defects and visible loose bodies. The sizes of the loose bodies estimated radiologically were fairly closely correlated with those found at surgery or autopsy.
Contagious equine metritis — Use of gas liquid chromatography in identifying the causal agent
Authors: NEILL S. D. , O'BRIEN J. J. , McMURRAY C. H. , BLANCHFLOWER W. J.
Published: April 2010

Cellular fatty acid compositions of contagious equine metritis isolates and three reference Haemophilus equigenitalis cultures were determined by gas chromatography. The chromatographic data were standardised and normalised fatty acid methyl ester (FAME) profiles were produced. The profiles were compared visually and similarity indices were determined using a computer peak matching method. There was little difference between the profiles of the three reference strains, each strain being characterised by three major fatty acids; C 18:1, C 16:0 and 30H‐C 14:0. Variations in cultural conditions had no significant effect on the FAME profiles. The identification of laboratory isolates using the technique was in agreement with the presumptive identification based on the currently recommended tests and an improvement on the confirmatory serological identification. The FAME profiles provided confirmation of identity where it was not possible to use the presently recommended serological procedures. The authors recommend the gas chromatography technique for use in the diagnostic laboratory as an adjunct to the presently accepted identification methods.
Arterial blood gas tension and acid base balance during exercise in horses with pharyngeal lymphoid hyperplasia
Authors: BAYLY W. M. , GRANT B. D. , BREEZE R. G.
Published: April 2010

Arterial blood gas and acid‐base values during maximal exercise over a 1.2 km distance were recorded in four Thoroughbred horses before and after the chemical induction of pharyngeal lymphoid hyperplasia (PLH). Samples were collected after galloping 0.8 km and 1.2 km, immediately upon stopping and 5 mins after exercising. In only one horse was any difference noted in the pre and post PLH induction results. The horse was more hypercapnoeic at the 1.2 km mark and also took much longer to complete the gallop when it had PLH. However, it also had signs of lower respiratory disease. In the other horses, the only changes which could be attributed to PLH were seen immediately upon stopping. It seems that PLH does not inhibit gas exchange during exercise unless the lesions are extremely severe.
Ulcerative colitis and protein losing enteropathy associated with intestinal salmonellosis and histoplasmosis in a horse
Authors: GOETZ T. E. , COFFMAN J. R.
Published: April 2010

Ulcerative colitis, protein losing enteropathy and intestinal histoplasmosis‐salmonellosis were diagnosed in a six‐year‐old Quarterhorse stallion. For six months before examination, the horse experienced a slow continual loss of weight. During the 17 day period of hospitalisation the horse developed progressive generalised oedema. On the 12th day of hospitalisation a severe profuse watery diarrhoea began; the horse was killed five days later.
Potassium concentration in equine red blood cells: Normal values and correlation with potassium levels in plasma
Authors: MUYLLE E. , VAN DEN HENDE C. , NUYTTEN J. , DEPREZ P. , VLAMINCK K. , OYAERT W.
Published: April 2010

The concentration of potassium in plasma and in red blood cells was determined in 948 horses. The coefficient of correlation between the two parameters was low. In 436 of these horses, which were clinically healthy, the red blood cell potassium (RBCK+) levels did not fit within a normal distribution curve, but a bimodal distribution was observed with a section point at 90 mmol/litre. In 90 per cent of these normal horses, mean RBCK+ content was 97.5 mmol/litre. In the remaining 10 per cent, mean RBCK+ concentration was 93.8 mmol/litre. A subdivision into a ‘low potassium group’ and a ‘high potassium group’ was made. In 10 out of 15 horses in the ‘low potassium group’, bimonthly sampling over a period of one year showed that RBCK+ content remained low. In the remaining five horses an increase was observed.
Observations on structure and function of the equine mitral valve
Authors: MILLER P. J. , HOLMES J. R.
Published: April 2010

The anatomy of the equine mitral valve and certain variations observed in 60 adult horses are described. The functional role of this valve, sited between the left atrium and the high pressure‐generating left ventricle, is discussed in relation to its anatomical structure. A method of examining the left side of the heart post mortem is described.
Serial investigations of early pregnancy in pony mares using real time ultrasound scanning
Authors: ALLEN W. E. , GODDARD P. J.
Published: April 2010

The uteri of 13 pony mares were examined daily by ultrasound during the first two months of gestation. The conceptus was first identified between 12 and 16 days after ovulation and the embryo was seen on the ventral surface of the conceptus after Day 21. The foetal heart could be visualised after Day 22 and spontaneous movement of the foetus occurred after Day 39. No consistent pattern was seen in the development of the foetal membranes, although attachment of the umbilical cord to the allantochorion was always on the dorsal aspect of the conceptus. Daily measurements were made of the diameter of the conceptus and the length of the embryo and foetus.
Thirteen cases of botulism in horses fed big bale silage
Authors: Ricketts S. W. , Greet T. R. C. , Glyn P. J. , Ginnett C. D. R. , McAllister E. P. , McCAIG J. , Skinner P. H. , Webbon P. M. , Frape D. L. , Smith G. R. , Murray L. G.
Published: April 2010

An outbreak of pharyngeal and limb paresis involving four horses and nine ponies in the south east of England is described. Nine of the animals died or were destroyed on humane grounds. The clinical features suggested a diagnosis of botulism and mouse innoculation tests confirmed the presence of type B toxin in the serum of one case. All animals were fed big bale silage. It is described how, in plastic wrapped silage manufacture, conditions of fermentation may be inadequate to prevent the growth of Clostridium botulinum. Examination of a sample of silage fed to the affected horses suggested that this was probably the source of the toxin.
Physiological stimuli of thirst and drinking patterns in ponies
Authors: SUFIT ELIZABETH , HOUPT KATHERINE A. , SWEETING MARTHA
Published: April 2010

The stimuli that elicit thirst were studied in four ponies. Nineteen hours of water deprivation produced an increase in plasma protein from 67 ± 0.1 g/litre to 72 ± 2 g/litre, a mean (± se) increase in plasma sodium from 139 ± 3 to 145 ± 2 mmol/litre and an increase in plasma osmolality from 297 ± 1 to 306 ± 2 mosmol/litre. Undeprived ponies drank 1.5 ± 0.9 kg/30 mins; 19 h deprived ponies drank 10.2 ± 2.5 kg/30 mins and corrected the deficits in plasma protein, plasma sodium and plasma osmolality as well as compensating for the water they would have drunk during the deprivation period.

In order to determine if an increase in plasma osmolality would stimulate thirst, 250 ml of 15 per cent sodium chloride was infused intravenously. The ponies drank when osmolality increased 3 per cent and when plasma sodium rose from 136 ± 3 mmol/litre to 143 ± 3 mmol/litre. Ponies infused with 15 per cent sodium chloride drank 2.9 ± 0.7 kg; those infused with 0.9 per cent sodium chloride drank 0.7 ± 0.5 kg. In order to determine if a decrease in plasma volume would stimulate thirst, ponies were injected with 1 or 2 mg/kg bodyweight (bwt) frusemide. Plasma protein rose from 68 ± 2 g/litre pre‐injection to 75 ± 2 g/litre 1 h after 1 mg/kg bwt frusemide and to 81 ± 1 g/litre 1 h after 2 mg/kg bwt frusemide. Ponies treated with 1 mg/kg frusemide voided 5.3 ± 0.81 kg urine and drank 3.0 ± 2 kg water. Ponies injected with 2 mg frusemide voided 6.4 ± 5 kg urine and drank 4.3 ± 1.4 kg water. Controls injected with 0.9 per cent sodium chloride voided 1.5 ± 0.5 kg urine and drank 0.9 ± 0.6 kg water. When food and water were freely available the ponies drank 27 ± 8 mins/day, 89 per cent of which occurred within a period from 10 mins before to 30 mins after feeding. They drank 8.7 ± 0.9 kg/day at a rate of 552 ± 232 ml/min. It was concluded that ponies usually drink periprandially and when challenged with either an increase in the osmotic pressure of their body fluids or a decrease in the volume of their body fluids they responded by increasing their water intake.
Coprophagy by foals: Effect of age and possible functions
Authors: CROWELL‐DAVIS SHARON L. , HOUPT KATHERINE A.
Published: April 2010

In colts and fillies observed from birth to 24 weeks old, coprophagy occurred from Weeks 1 to 19. Its frequency was greatest during the first two months. Coprophagy was rarely observed in mares and stallions. Foals usually ate the faeces of their mother but were observed to eat their own and those of a stallion and another unrelated mare. Urination by the foal occurred before, during or after 26 per cent of the coprophagy incidents. It is hypothesised that foals may consume faeces in response to a maternal pheromone which signals the presence of deoxycholic acid or other acids which the foal may be deficient in and which it may require for gut immunocompetence and myelination of the nervous system. Such a pheromone may also serve to accelerate growth and sexual maturation. Coprophagy may also provide nutrients and introduce normal bacterial flora to the gut.
Feed preferences of ponies
Authors: HAWKES J. , HEDGES M. , DANILUK P. , HINTZ H. F. , SCHRYVER H. F.
Published: April 2010

Preference trials were conducted with mature ponies. In Trial 1, oats were compared with oats plus sucrose. Four of six pony geldings selected oats plus sucrose, but one pony demonstrated a dislike for sucrose and one selected from the bucket on the right side regardless of content. Oats, maize, barley, rye and wheat were compared in Trial 2 using six mature pony mares. Oats were the preferred grain, with maize and barley ranking second and third respectively. Wheat and rye were the least preferred. Even though the ponies demonstrated preference, the total intake at a given meal was not greatly depressed when only the less palatable grains were fed. In Trial 3, pony mares selected a diet containing 20 per cent dried distillers' grain and 80 per cent of a basal mixed diet of maize, oats, wheat bran, soybean meal, limestone and molasses over 100 per cent basal mixed diet, but selected the basal diet over diets containing 20 per cent blood meal, beet pulp or meat and bone meal and 80 per cent basal diet. They did not differentiate against diets containing 20 per cent alfalfa meal or 10 or 5 per cent meat and bone meal when the diets were compared to the basal mixed diet.
Distribution of substance P‐like immunoreactivity in the enteric neurons of the large colon of normal and amitraz‐treated ponies: An immunocytochemical study
Authors: CUMMINGS J. F. , SELLERS A. F. , LOWE J. E.
Published: April 2010

The distribution of the putative motor excitatory neurotransmitter, substance P, was studied immunocytochemically in the left dorsal colon of four normal control ponies and three ponies with amitraz‐induced impaction colic. Substance P‐like immunoreactivity in the control ponies was observed in nerve fibres in all layers of the bowel wall and in the nerve cell bodies of the enteric ganglia. The substance P‐like immunoreactivity was clearly more intense in the cell bodies of submucosal ganglia than in those of the myenteric ganglia. The internodal nerve strands of the myenteric plexus were very rich in substance P‐like immunoreactivity and within the ganglia they formed dense varicose networks around the neuronal cell bodies. Nerve bundles rich in substance P‐like immunoreactivity diverged inward from the myenteric plexus to contribute an abundance of varicose immunoreactive fibres to the circular muscle of the tunica muscularis. Nerve fascicles with substance P‐like immunoreactivity were sparse in the longitudinal muscle except in the thickened taenial band. In the submucosa many of the nerve fibres with substance P‐like immunoreactivity appeared to arise from ganglionic cell bodies. Immunoreactive fibres commonly condensed around arterial vessels in the submucosa. Fine immunoreactive nerve fascicles from the submucosal plexus also projected internally to supply the muscularis mucosae and form periglandular arrays in the lamina propria. The distribution of substance P‐like immunoreactivity in the normal equine colon differed in some respects from patterns observed in large intestines of other mammals. When the colons of normal and amitraztreated ponies were compared no differences were discerned in the distribution or intensity of substance P‐like reactivity.
Tendon injuries in horses treated with carbon fibre implants
Authors: VAUGHAN L. C. , EDWARDS G. B. , GERRING E. L.
Published: April 2010

Implants of carbon fibre, made by plaiting a tow of 10,000 filaments of Grafil type HT‐S, were used to treat strains and ruptures of digital flexor tendons in 46 horses. The relevant clinical data, the techniques employed and an analysis of the results are described. Apart from two horses in which the implant was extruded and had to be removed, there were minimal untoward consequences of the surgery. Of the 34 horses with acute or chronic tendinitis, 14 returned to racing, seven were used as hunters and seven as hacks. Among the former group, seven suffered a further strain while racing but the others performed well for some time. Twelve horses with severed tendons recovered well and only in one did infection occur. Overall the results in the latter were better than had previously been achieved using other repair materials.
Clinical anaesthesia in the horse: Comparison of enflurane and halothane
Authors: TAYLOR P. M. , HALL L. W.
Published: April 2010

Anaesthesia was induced in 24 horses with xylazine and ketamine and maintained with halothane (12 cases) or enflurane (12 cases) in oxygen. Pulse rate, arterial blood pressure, arterial blood gas values, respiratory rate and tidal volume were measured at regular intervals during anaesthesia. Serial venous blood samples were taken for assay of glucose, urea, haemoglobin, packed cell volume, gamma glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase and creatine kinase. Operating conditions and the horses' behaviour in the recovery period were also recorded. In the case of the group of horses receiving enflurane, difficulty was experienced maintaining anaesthesia deep enough for surgery. This group also displayed greater respiratory depression. There were no significant differences between arterial blood pressure values, or any of the haematological or biochemical parameters recorded in each group. Recovery from anaesthesia was significantly faster in horses receiving enflurane but less smooth. It was concluded that, although enflurane appeared to be safe in the horse, the respiratory depression and the unpleasant recovery did not make it a desirable alternative to halothane.
Racing with the dragon
Authors: GREET T. R. C.
Published: April 2010

The Richard Hartley Clinical Prize, sponsored by Arnolds Veterinary Products, was won in 1982 by Mr Tim Greet for his papers ‘Observations on the potential role of oesophageal radiography in the horse’ and ‘Windsucking treated by myectomy and neurectomy’, which appeared in the January and October issues of EVJ on pages 73–79 and 299–301, respectively. Mr Greet used the prize money to visit Hong Kong, spending some of his time at the Royal Hong Kong Jockey Club, and his experiences of the small but populous colony are reported here.
Clinical pharmacology and therapeutic uses of non‐steroidal anti‐inflammatory drugs in the horse
Authors: LEES P. , HIGGINS A. J.
Published: April 2010

Weak organic acids possessing anti‐inflammatory, analgesic and antipyretic properties — commonly known as aspirin‐like drugs — have been used in equine medicine for almost 100 years. These non‐steroidal anti‐inflammatory drugs (NSAIDs) may be classified chemically into two groups; the enolic acids such as phenylbutazone and carboxylic acids like flunixin, meclofenamate and naproxen. All NSAIDs have similar and possibly identical modes of action accounting for both their therapeutic and their toxic effects. They block some part of the cyclo‐oxygenase enzyme pathway and thereby suppress the synthesis of several chemical mediators of inflammation, collectively known as eicosanoids. The available evidence indicates that some of the newer NSAIDs have a reasonable safety margin but further studies are required. The toxicity of phenylbutazone in the horse has been investigated very thoroughly in recent years and it has been shown to cause renotoxicity and, most significantly, ulceration of the gastrointestinal tract when relatively high doses are administered. Several factors may predispose towards phenylbutazone toxicity in the horse, including breed and age, but high dosage is considered to be particularly important. The absorption into, and fate within, the body of NSAIDs are considered and particular attention is drawn to the ways in which these pharmacokinetic properties relate to the drugs' toxicity and clinical efficacy. In reviewing current knowledge of the clinical pharmacology of this important group of drugs, it is hoped to provide the clinician with a rational, scientific basis for their safe and effective use in equine practice.
Endoscopic and virological observations on respiratory disease in a group of young Thoroughbred horses in training
Authors: BURRELL M. H.
Published: April 2010

A group of racehorses in training was examined on several occasions with a fibreoptic endoscope and monitored for viral infection. Only equine herpes virus‐2 (EHV‐2) infection was detected. Pharyngeal lymphoid hyperplasia (PLH) was present in all horses and decreased in severity with age. There was no association between PLH severity and antibody titres to EHV‐1, or with the isolation of EHV‐2. Finishing position in races was not affected by PLH severity. Exercise induced pulmonary haemorrhage (EIPH) was evident on 23 out of 49 (47 per cent) examinations after maximal speed training exercise. Eighteen out of 19 (95 per cent) horses examined on at least two occasions had EIPH but its occurrence was not predictable. Observable mucoid or mucopurulent exudate was present in the trachea in 60 out of 118 (50 per cent) examinations and the amount seen was increased following exercise.
Turbidimetric measurement of IgG(T) in the serum of healthy Thoroughbreds and ponies
Authors: KENT JOYCE E. , BLACKMORE D. J.
Published: April 2010

The turbidimetric analysis of IgG(T) in the serum of horses is described. Reference values are provided for ‘worm‐free’ ponies (2.6 ± 0.7 g/litre), stabled Thoroughbreds two years old and over (4.1 ± 1.3 g/litre), grazing Thoroughbred broodmares (7.1 ± 2.4 g/litre) and regularly wormed adult and young ponies grazing pasture contaminated with intestinal parasite eggs and larvae.
Use of guaiacol glycerine ether in clinical anaesthesia in the horse
Authors: BROUWER G. J.
Published: April 2010

A total of 103 anaesthetic inductions were performed in horses for a variety of elective procedures. All cases were premedicated with acepromazine maleate (0.02 to 0.05 mg/kg body weight [bwt] intramuscularly [im]). In 50 cases (Group A) anaesthesia was induced by a single intravenous (iv) bolus of thiopentone sodium (11.1 mg/kg bwt or 1 g/90 kg bwt) followed immediately by a bolus of suxamethonium chloride (0.1 mg/kg bwt). In 53 cases (Group B) anaesthesia was induced using iv guaiacol glycerine ether (GGE) (approximately 50 mg/kg bwt) followed by a bolus of thiopentone at half the usual dose rate (5.6 mg/kg bwt or 1 g/180 kg bwt). Induction of anaesthesia was uneventful in both groups although in Group B it was particularly smooth. Following endotracheal intubation anaesthesia was maintained with halothane in oxygen administered via a circle system. The duration of anaesthesia was comparable between the two groups; however, the mean (± sd) time to standing in Group B, 35 ± 22 mins, was significantly shorter than in Group A, 48 ± 25 mins. The use of the GGE/thiopentone technique is discussed.
Lag screw fixation of sagittal navicular bone fractures in five horses
Authors: NÉMETH F. , DIK K. J.
Published: April 2010

A sagittal fracture of the navicular bone in five horses was treated by means of lag screw. Intra‐operative radiographic monitoring and a specially developed guide apparatus was necessary to implant the screw precisely along the transverse axis of the navicular bone. Internal fixation resulted in progressive radiographic narrowing of the fracture zone. In all five patients the fracture healed (bony union) without superfluous callus formation.
Review of exercise induced pulmonary haemorrhage and its possible relationship with mechanical stress
Authors: CLARKE A. F.
Published: April 2010

Exercise induced pulmonary haemorrhage (EIPH) is a condition of uncertain aetiology. This article reviews the evidence relating to its incidence, clinical findings, radiological observations, histopathology and certain aspects of respiratory physiology. It is proposed that EIPH is primarily caused by mechanical stress in the dorsocaudal region of the lung.
Do magnetic fields influence soft tissue wound healing?— A preliminary communication
Authors: LEAPER D. J. , FOSTER M. E. , BRENNAN S. S. , DAVIES P. W.
Published: April 2010

Magnetic fields have been considered for treating many ailments over man's history. There have been many anecdotal unsupported claims for successful treatment of soft tissue injury although reports have been more substantive in the orthopaedic field. The widespread clinical and veterinary use of a light self‐adhesive magnetic foil in Europe prompted this trial of experimental wound healing.

One hundred and sixty Sprague‐Dawley rats had a linear 2.5 cm incision or a circular 1 cm skin defect made over the mid‐dorsal spine. Equal numbers were randomised to receive either a magnetic foil or a dummy (control) dressing. At three, seven, 10 or 14 days linear wounds were distracted using a tensiometer; open defects were measured, excised and assayed for collagen content; 14‐day wounds were examined histologically.

Although wound tensile strengths increased and open wounds decreased in size with increase of hydroxyproline, there were no statistically significant differences between treated or control animals.

Although easy to apply the alternate magnetic foil (giving 400 Gauss at 7 mm) conferred no statistically significant effect on soft tissue healing.
Observations on seven cases of mitral insufficiency in the horse
Authors: MILLER P. J. , HOLMES J. R.
Published: April 2010

Observations on seven cases of mitral insufficiency are described. Three of the horses had recent histories of cardiac failure and formed a separate group in which there were marked haemodynamic changes which varied in relation to heart rate but were associated with pulmonary hypertension, elevated right ventricular pressure and low peak left ventricular pressure. In the other four horses the heart appeared to be compensating at rest but to be unable to cope with severe exertion. On auscultation, a widespread pansystolic murmur and a prominent third heart sound were characteristic of the left ventricular volume overload.

Microscopic changes were found in one left papillary muscle. The possibility that changes in the position of the papillary muscles consequent upon left ventricular dilatation may lead to or exaggerate mitral valve eversion is discussed.
Case of angiosarcoma of the nasal passage of the horse — Ultrastructure and differential diagnosis from progressive haematoma
Authors: CHAN C. W. , COLLINS E. A.
Published: April 2010

An angiosarcoma involving the right frontal and maxillary sinuses in a nine‐year‐old Thoroughbred mare was studied post mortem by light and electron microscopy. Important diagnostic features included malignant endothelial cells lining ill‐defined vascular spaces, supported by other vasoformative elements. Rhabdomyoblasts were also found. The tumour is apparently rarely seen in the nasal passages of the horse.
Bilateral laryngeal paralysis in the horse
Authors: DUNCAN I. D. , BROOK D.
Published: April 2010

Four two‐year‐old Thoroughbreds suffered an acute gastrointestinal illness shortly after dosing with mineral oil which was thought to have been contaminated with an organophosphate compound. Three weeks later all four were noted to be dyspnoeic and endoscopic examination showed that they had developed bilateral laryngeal paralysis. Two of the horses died during severe bouts of dyspnoea six and eight months later and the third was killed shortly thereafter. Examination of the left and right recurrent laryngeal nerves from these horses showed a severe loss of myelinated fibres distally, especially in the left nerve. A similar but less severe lesion was seen in other long peripheral nerves, including the phrenic and digital nerves of the third horse. The spinal cord in two horses showed evidence of mild axonal degeneration which was not related to a particular tract or location. The fourth horse had bilateral laryngeal paralysis two years later. The acute clinical signs and delayed neurological sequelae seen in these horses were strongly suggestive of accidental organophosphate toxicity.
Chemical restraint of the standing horse
Authors: TAYLOR POLLY M.
Published: April 2010

This paper describes the agents available for chemical restraint in the standing horse. General principles of the use of tranquillisers, sedatives and the opiates are discussed. The effects and techniques for administration of a number of drug combinations are detailed, with particular emphasis on sedative/opiate combinations.