bluuebunny/crossref_metadata_2025 huggingface dataset:
Gentamicin dosage in foals aged one month and three months
Authors: BAGGOT J. DESMOND , LOVE DARIA N. , STEWART JENNIFER , RAUS J.
Published: April 2010

The absorption and disposition kinetics of gentamicin were compared at two dosage levels (2 and 4 mg/kg bodyweight [bwt]) in one‐ and three‐month‐old foals. Following intramuscular (im) injection of single 2 mg/kg bwt doses, the drug was absorbed rapidly and produced peak serum concentration (18.2 μ 5.3 ±g/ml, n = 8) at 30 mins. Much wider variations were associated with the amount of drug absorbed and the serum gentamicin concentrations after administration at the higher dosage level. The half‐life of gentamicin was similar in the one‐month‐old (3.7 ± 1.7 h, n = 8) and three‐month‐old (3.3 ± 0.8 h, n = 8) foals, and was independent of the dose. One‐month‐old foals did not appear to have a deficiency in renal excretion of gentamicin. The minimum inhibitory concentration of gentamicin for Corynebacterium equi and certain other equine bacterial isolates was less than 0.195 μg/ml. It was concluded that 2 mg/kg bwt administered by im injection at 8 to 12 h intervals, depending on the severity of the infection, could be recommended as the dose rate for treatment of systemic infections caused by microorganisms that are susceptible to gentamicin.
Temporary bilateral carotid artery occlusion as an aid to nasal surgery in the horse
Authors: WYN‐JONES G. , JONES R. S. , CHURCH S.
Published: April 2010

One of the major obstacles to successful intranasal surgery in the horse is haemorrhage, even minor interferences causing profuse bleeding. Conventional techniques for haemostasis are ineffective or inhibit the progress of the surgery. Temporary bilateral occlusion of the common carotid artery resulted in a substantial reduction in haemorrhage during intranasal surgery in five horses, with much improved visibility and facility of operation. The large contribution to the circle of Willis by the ventral spinal artery is believed to prevent cerebral ischaemia during this procedure. This paper describes the technique of temporary bilateral ligation of the common carotid artery and emphasises the importance of ancillary techniques such as packing of the nasal cavity and general postoperative management.
Comparison of the measurement of plasma testosterone and plasma oestrogens for the diagnosis of cryptorchidism in the horse
Authors: COX J. E. , REDHEAD PATRICIA H. , DAWSON FIONA E.
Published: April 2010

The results of performing 1720 blood tests for equine cryptorchidism are described. Using the paired sample human chorionic gonadotrophin (hCG) stimulation test and measuring testosterone, 6.7 per cent of tests did not give a clear result. If only the testosterone concentration in the pre‐hCG blood sample was used, this percentage rose to 14 per cent. The paired sample hCG stimulation test was 94.6 per cent accurate. A comparison was made between the paired hCG stimulation test and the measurement of conjugated oestrogen in a single sample. The latter did not give as many doubtfuls but gave false negatives in donkeys of all ages and in horses less than three years old. Measurement of conjugated oestrogen was found to be 96 per cent accurate when donkeys and young horses were excluded. It is, therefore, recommended as a simpler and more reliable test than the paired sample hCG test, but only in the older horse.
Synovial fluid and plasma kinetics of methylprednisolone and methylprednisolone acetate in horses following intra‐articular administration of methylprednisolone acetate
Authors: AUTEFAGE A. , ALVINERIE M. , TOUTAIN P. L.
Published: April 2010

Synovial fluid and plasma kinetics of methylprednisolone acetate (MPA) and methylprednisolone (MP) after a single intra‐articular administration of MPA at a therapeutic dose (111 mgin toto) was measured in five horses. MPA was detected in synovial fluid for two to six days post injection and MP, which results from synovial MPA hydrolysis, was present in pharmacologically significant concentrations for 4.8 to 39 days, depending on the horse. MPA synovial concentration was maximal (289 ± 284 μg/ml) at the first sampling time (2 h after administration) and MP synovial concentration was maximal (from 58.9 to 379.5 μg/ml) at the first or second sampling time (2 to 10 h after administration). Thereafter, both MP and MPA declined rapidly. From time of administration to about five days later, MP synovial fluid concentration fell progressively with a half‐time of 9.95 h. Subsequently, the MP synovial fluid concentration decreased more slowly with an apparent half‐time of 115 h. During the first 24 h following MPA administration, trace amounts of MP (less than 5 ng/ml) were detected in plasma. Plasma hydrocortisone levels were depressed for three to four days after administration but adrenal responsiveness to adrenocorticotrophic hormone tests remained unaffected.
Radiographic assessment of navicular bones, based on changes in the distal nutrient foramina
Authors: MACGREGOR CHRISTINA M.
Published: April 2010

Radiographic examination of the navicular bones of 258 horses was carried out. Of these 258 horses, 83 were sound (Group A), 151 had been diagnosed clinically as having navicular disease (Group B), and 24 had a forefoot lameness of unknown aetiology (Group C). Seven basic shapes of distal nutrient foramina were identified from these radiographs. A scoring system was then developed based on these different types of distal nutrient foramina. When this scoring system was applied to the radiographs of the 258 horses examined significant differences were found between the mean navicular scores of the horses in Groups A, B and C. It is considered that this navicular scoring system could be very useful for comparing radiographs of the navicular bones of different horses and recording serial radiographs of navicular bones of the same horse.
Review of large intestinal motility and mechanisms of impaction in the horse
Authors: SELLERS A. F. , LOWE J. E.
Published: April 2010

The large intestine has distinct motility patterns which include non‐rhythmic haustral kneading of ingesta and stronger rhythmic retropulsive and propulsive contractions which move ingesta along the tract. A variable site electrical pacemaker exists at the pelvic flexure where the strong rhythmic contractions begin. The large intestine can contract adequately with only the intrinsic nerve supply intact. Neurotransmitters have profound effects on large intestinal activity.
Incidence, diagnosis and treatment of postoperative complications in colic cases
Authors: HUNT JUDITH M. , EDWARDS G. B. , CLARKE KATHY W.
Published: April 2010

A survey of 259 surgical colic cases revealed that over 50 per cent of fatalities occurred in the postoperative period. Post‐operative ileus and circulatory/endotoxaemic shock accounted for 70 per cent of these deaths. Other less important complications were salmonellosis, long bone fracture, adhesions, haemorrhage, laminitis, wound infection and ischaemic muscle damage. Close monitoring of postoperative progress is necessary to enable early diagnosis and treatment. Recent developments in understanding of the pathophysiology of endotoxic shock and ileus may lead to more successful treatment regimes. The possibilities include the use of cyclo‐oxygenase inhibitors, anti‐endotoxin hyperimmune serum and dopamine antagonists.
Haemostatic abnormalities in horses with colic — Their prognostic value
Authors: JOHNSTONE I. B. , CRANE S.
Published: April 2010

The incidence and nature of coagulation abnormalities in horses presented with colic and the possible prognostic value of these abnormalities was investigated. A coagulogram was performed on each of 24 adult Thoroughbred or Standardbred horses. A coagulogram consisted of measurements of eight parameters; platelet count, plasma fibrinogen, plasma antithrombin III (AT), partial thromboplastin time (PTT), prothrombin time (PT), thrombin clotting time (TCT), soluble fibrin monomer (SFM) and fibrin‐fibrinogen degradation products (FDP). Retrospective determination of the cause of the colic and outcome (survival vs non‐survival) was carried out. All patients examined had at least one abnormal parameter with the frequency being: Increased SFM 67 per cent; prolonged PTT 63 per cent; prolonged TCT 50 per cent; elevated plasma fibrinogen 46 per cent; reduced platelet count 29 per cent; reduced plasma AT 29 per cent; prolonged PT 25 per cent; and elevated serum FDP 21 per cent. When survivor and non‐survivor groups were compared there was little difference in the frequency of abnormalities such as elevated SFM, elevated fibrinogen and prolonged PTT. The abnormalities which had the greatest frequency difference between non‐survivors and survivors, and therefore the greatest prognostic value, were decreased AT > prolonged TCT = prolonged PT > elevated FDP > reduced platelet count. The frequency of these abnormalities in non‐survivors compared to survivors was 8.6:1, 7.1:1, 5.7:1 and 3.6:1, respectively. The average number of abnormal parameters in non‐survivors (five) was significantly greater than in survivors (two).
Colitis: Differential diagnosis and treatment
Authors: WHITLOCK R. H.
Published: April 2010

Equine colitis characterised by diarrhoea and/or pain may be caused by a wide variety of bacterial, viral, protozoal agents and toxins. The causative agent of Potomac horse fever,Ehrlichia risticii, is the most recently recognised cause of colitis. Salmonella, the agent typically associated with colitis, also causes abdominal pain (colic) of variable intensity. Acute colitis is also caused by colitis X, various antibiotics, endotoxic shock and peritonitis caused by arterial infarction. The principles of therapy for each of these, together with means of differential diagnosis, are presented.
Gastric ulceration in mature Thoroughbred horses
Authors: HAMMOND C. J. , MASON D. K. , WATKINS K. L.
Published: April 2010

Routine post mortem examination of 195 Thoroughbreds in Hong Kong revealed that 66 per cent suffered from gastric ulceration. Racehorses killed straight out of training suffered a significantly greater incidence of ulceration (80 per cent) than those having been retired for a month or more (52 per cent). The macroscopic findings post mortem enabled a classification of equine gastric ulceration to be suggested (Types 1, 2, 3), according to severity. Severe lesions (Types 2 and 3) were present in 45 per cent of horses put down from training and 5 per cent of retired horses. This difference was significant. Lesions appeared to be chronically progressive during training, but to regress during retirement. The observed difference of gastric ulceration between the two groups of horses was similar for different age groups.
Gastric rupture in horses: A review of 54 cases
Authors: TODHUNTER R. J. , ERB HOLLIS N. , ROTH LOIS
Published: April 2010

The historical, clinical, laboratory, surgical and necropsy findings in 54 cases of gastric rupture in horses are described. Eleven per cent of the deaths of horses undergoing exploratory coeliotomy for colic during the period of the study were a result of gastric rupture. Comparison with all horses which had exploratory coeliotomies for colic over an eight year period did not show that horses with gastric rupture were different from these reference horses regarding age, breed or season. There were fewer stallions than expected in the gastric rupture group. Horses with histories of both acute and chronic (more than 36 h) colic were susceptible to gastric rupture. Primary and idiopathic causes of gastric dilation and rupture accounted for about one‐third of the horses. All but one of these cases resulting from secondary causes fell into three aetiologically‐related groups: obstructive, peritoneal and enteric, with approximately equal numbers of horses in each group. Most of the ruptures occurred along the greater curvature of the stomach. At least six horses ruptured their stomachs post‐operatively in the presence of an indwelling nasogastric tube. The presence or absence of gastric reflux following nasogastric intubation was not a reliable indicator, on its own, of gastric dilation. Horses that later died from gastric rupture had markedly elevated heart rate, hypochloraemia, peritoneal exudative effusion (particularly with evidence of sepsis), pre‐and/or postoperative gastric reflux and small or large intestinal disease. However, no distinctive feature of these horses was shown to place them at risk of gastric rupture.
Gastroduodenal ulceration in foals
Authors: BECHT J. L. , BYARS T. DOUGLAS
Published: April 2010

Gastroduodenal ulceration is becoming recognised as an important disease ***in ***foals during the first few months of life. Aetiopathogenesis is presumed to be similar to peptic disease in humans associated with back diffusion of hydrogen ions into the mucosa. Many factors have been incriminated as predisposing foals to ulceration but few have been proven. To date, use of non‐steroidal anti‐inflammatory agents has been the only documented cause of gastroduodenal ulceration in foals. The clustering of affected foals on certain farms suggests an infectious aetiology but attempts to identify a causative organism have been unsuccessful. Four clinical syndromes defined for foals with gastroduodenal ulceration include: (1) silent ulcers, which occur most often in the non‐glandular stomach along the margo plicatus and are identified as incidental findings at necropsy; (2) active ulcers which are often manifested by abdominal pain, excessive salivation and bruxism; (3) perforating ulcers which usually result in a severe, diffuse peritonitis; and (4) pyloric or duodenal obstruction from a healing ulcer. General approaches to therapy of a foal with active ulceration consist of reduction of gastric acidity and enhancement of mucosal protection. Antacids and type 2 histamine receptor antagonists are used most often to neutralise or decrease acid secretion, respectively. Sucralfate, a locally active sulphated sucrose preparation, is commonly used as a cytoprotective agent. The efficacy and safety of many products used have not been evaluated adequately in foals. Perforating ulcers are usually associated with death or humane destruction of the foal because of fulminating peritonitis. Surgical intervention and bypass procedures are indicated in foals that develop pyloric or duodenal obstructions from healing ulcers.
Surgical management of intussusception in the horse
Authors: EDWARDS G. B.
Published: April 2010

During a 14 year period, 27 of 310 horses undergoing laparotomy because of abdominal pain were found to have an intussusception involving the small intestine (16 cases) or caecum (11 cases). The clinical signs, operative findings and techniques adopted to overcome the obstruction are described. An evaluation of possible predisposing factors provided further evidence of the important role of the tapewormAnoplocephala perfoliatain initiating intussusception involving the ileum and caecum.
Resection and anastomosis of small intestine: Current methods applicable to the horse
Authors: EDWARDS G. B.
Published: April 2010

Intraoperative techniques for assessing the viability of ischaemic bowel are discussed. Intravenous administration of sodium fluorescein appears useful but further investigation of the method is required. Methods of resection and anastomosis of small intestine are described and illustrated, including the use of automatic stapling instruments.
Observations on the long term effects of Brucella abortus infection in the horse, including effects during pregnancy and lactation
Authors: MACMILLAN A. P. , COCKREM D. S.
Published: April 2010

Five mares and a stallion were studied from three to 30 months after experimental infection with Brucella abortus strain 544. The mares bred normally. No organisms were recovered from horses or from pregnant Friesian heifer contacts. Titres of serum antibody in the antiglobulin (Coombs) and complement fixation tests fell more slowly than those assessed by other tests. The serum of one foal yielded maternal antibody. An intradermal test was positive in infected adults only, and negative in all foals.
Elastase‐producing microorganisms in horse lungs: Their possible role in the pathogenesis of chronic pulmonary disease in the horse
Authors: GRÜNIG GABRIELE , VON FELLENBERG R. , MAIER R. , CORBOZ L.
Published: April 2010

Seventeen out of 21 horses had pulmonary microbial organisms which reached considerable numbers in seven cases. Elastase‐producing microorganisms from the environment (Streptomycesspecies and to a lesser extentBacillusspecies) constituted 22 per cent to 99 per cent (mean 79 per cent) of the total growth. There was a considerable number of microorganisms within vitro‐produced elastases which were not or only slightly affected by horse serum. There was no correlation between numbers of organisms and pulmonary histopathological findings thus the significance of these microorganisms in the pathogenesis of alveolar emphysema is unknown. The growth of a strain ofStreptomyces collinus/diastatochromogusisolated from the lungs was suppressed by fresh horse serum but not by decomplemented horse serum. Complement activation in response to this organism could contribute to airway inflammation through the production of mediators.
Pulmonary changes associated with flotation techniques in the treatment of skeletal injuries in the horse
Authors: McCLINTOCK S. A. , HUTCHINS D. R. , LAING E. A. , BROWNLOW M. A.
Published: April 2010

Six adult horses with normal blood gas values, normal thoracic radiographs and free from overt signs of respiratory disease were confined in flotation tanks for periods from one to seven weeks. With one exception, they all coughed, had a variable amount of nasal discharge and, at autopsy, showed cranio‐ventral alterations to their lungs which were characterised by patchy irregular areas of absorption atelectasis with or without an inflammatory reaction and an accompanying alveolar emphysema.
Glycogen depletion patterns in the muscle of Standardbred Trotters after exercise of varying intensities and durations
Authors: VALBERG STEPHANIE
Published: April 2010

The glycogen depletion patterns in the gluteus muscle of Standardbred horses were studied under different trotting intensities. After racing significant glycogen depletion was found in all Type I and IIA fibres and in a varying percentage of Type IIB fibres, depending on the individual horse. When horses performed exercise over a short distance (5 to 8 km) at three different speeds, glycogen depletion was difficult to detect for the faster speeds (10 and 8 m/sec) but notably involved a major proportion of Type I fibres at the slowest speed (6 m/sec). When exercise was prolonged over a greater distance a larger proportion of Type IIA fibres were depleted at faster speeds (8 m/sec) than at slower speeds over the same distance. However, when slow trotting was continued over even greater distances, a gradual increase in the percentage of glycogen‐depleted Type IIA fibres was noticed. Very significant glycogen depletion in all three fibre types was seen in all horses where a near maximal exercise tolerance test was performed 3 h after the longest and slowest exercise run. In a further study of glycogen depletion, during a near maximal exercise tolerance test on a graded treadmill with consecutively increasing velocity, depletion was seen in a proportion of all three fibre types with the highest proportion being Type I and the lowest Type IIB.
Effects of propranolol on cardiopulmonary function in the pony during submaximal exercise
Authors: SEXTON W. L. , ERICKSON H. H.
Published: April 2010

Cardiopulmonary responses of four ponies were monitored during standard exercise tests (SET), before and after β‐adrenergic receptor blockade with propranolol. The SET consisted of four 5 min increments of increasing speed from 1.0 to 2.8 m/sec on a treadmill at a 7° incline. Data were collected at rest, throughout the SET and recovery. Administration of propranolol to ponies at rest had no effect on cardiopulmonary function. During the SET, increases in heart rate, mean pulmonary artery flow velocity (an index of cardiac output) and right ventricular dP/dt (an index of myocardial contractility) were progressively attenuated as running speed increased. Body temperature and mean pulmonary artery and right ventricular pressures were significantly elevated over normal. Propranolol treatment had no effect on the responses of mean arterial pressure, haematocrit, haemoglobin, blood lactate and arterial blood gases and pH to the SET. These results suggest that in the pony there is no sympathetic activity to the heart at rest and that during exercise there is pulmonary vasodilation mediated by β‐adrenergic receptors.
Low dose flunixin meglumine: Effects on eicosanoid production and clinical signs induced by experimental endotoxaemia in horses
Authors: SEMRAD SUSAN D. , HARDEE G. E. , HARDEE MARILYN M. , MOORE J. N.
Published: April 2010

The efficacy of low doses of flunixin meglumine in reducing eicosanoid generation and clinical signs in response to experimentally induced endotoxaemia was investigated. Thromboxane H2and 6‐keto‐prostaglandin F1αwere measured in serum and plasma by radioimmunoassay. Plasma flunixin concentrations were determined by high performance liquid chromatography and pharmacokinetic parameters derived non‐compartmentally. In horses administered flunixin meglumine before endotoxin challenge, a significant suppression in plasma thromboxane B2and 6‐keto‐prostaglandin F1αgeneration was observed. Elevations in blood lactate were significantly suppressed in horses pre‐treated with 0.25 mg/kg bodyweight flunixin meglumine. Reduction of the clinical signs of endotoxaemia by flunixin meglumine was dose dependent. Low doses of flunixin inhibited eicosanoid production without masking all of the physical manifestations of endotoxaemia necessary for accurate clinical evaluation of the horse's status.
Serum retinol, 25‐hydroxyvitamin D and α‐tocopherol of racing Trotters in Finland
Authors: MÄENPÄÄ P. H. , LAPPETELÄINEN RAILI , VIRKKUNEN J.
Published: April 2010

Serum levels of retinol, 25‐hydroxyvitamin D2, 25‐hydroxyvitamin D3 and α‐tocopherol were determined by high performance liquid chromatography from 142 Standardbred and Finnish Coldblooded Trotters aged three to 15 years. Blood samples were collected during January and July. Serum levels of retinol and α‐tocopherol were about a third of those in man, with summer values indicating an increase in most horses. The relatively low serum concentrations of 25‐hydroxyvitamin D and α‐tocopherol suggest that during the winter season a deficiency of these vitamins may occur in horses in northern countries such as Finland. Significant differences were observed between values of horses from different stables, especially for serum α‐tocopherol. The differences probably reflect differences in the quality of feeds and/or different feeding practices.
Immunohistochemical evaluation of the equine endometrium during the oestrous cycle
Authors: WAELCHLI R. O. , WINDER N. CHRISTINE
Published: April 2010

Endometrial biopsies were obtained from four mares during consecutive oestrous cycles on the first day of oestrus, on the day when ovulation was detected, and four and eight days after ovulation. Cycle stages were confirmed by means of rectal palpation, ultrasonography and plasma progesterone determination. Immunohistochemical evaluation of the formalin fixed biopsy specimens was performed using a peroxidase anti‐peroxidase technique. Immunoglobulin (Ig)A‐, IgM‐, IgG(Fc)‐ and IgG(T)‐containing cells were detected in all biopsies; with IgA‐ and IgG(Fc)‐containing cells generally predominating. There was no cyclical trend of Ig‐containing cell numbers for any isotype. Free immunoglobulins of the four classes evaluated were frequently seen in luminal epithelium, glandular epithelium and secretions, and interstitium. This study of endometrial biopsies from a limited number of cycling mares suggests the presence in the equine endometrium of free and intracellular immunoglobulins of the classes A. M., G(Fc) and G(T) without any apparent cyclical trend.
Surgical treatment of fractures of the olecranon in the horse: A comparative review of 25 cases
Authors: DENNY H. R. , BARR A. R. S. , WATERMAN A.
Published: April 2010

A series of 25 horses with olecranon fractures are reviewed. Twenty‐one cases were treated surgically by the application of a tension band plate to the caudal aspect of the ulna. Seventy six per cent of these regained full limb function. The results of treatment are compared with two other series of conservatively and surgically treated cases.
Observations on headshaking in the horse
Authors: LANE J. G. , MAIR T. S.
Published: April 2010

The clinical records of 100 cases of headshaking in horses were reviewed. Possible causes of the abnormal behaviour were identified in 11 animals; these included ear mite infestation, otitis interna, cranial nerve dysfunction, cervical injury, ocular disease, guttural pouch mycosis, dental periapical osteitis and suspected vasomotor rhinitis. However, in only two of these could it be shown that correction of the abnormality led to elimination of the headshaking. The additional clinical signs exhibited by the other idiopathic cases of headshaking included evidence of nasal irritation, sneezing and snorting, nasal discharge, coughing and excessive lacrimation. Many of these horses also showed a marked seasonal pattern with respect to the onset of the disease and the recurrence of signs in subsequent years. The clinical presentation of idiopathic headshakers and the seasonal incidence of the signs closely resemble allergic rhinitis in man.
Pathogenesis of degenerative joint disease
Authors: CLYNE M. J.
Published: April 2010

Proteoglycan degradation is central to the development of degenerative joint disease. Proteoglycans may be degraded by lysosomal enzymes from chondrocytes, synoviocytes or leucocytes. Collagen and matrix degradation occurs either by direct damage or due to degrading enzymes released into synovial fluid. Once the pathological sequence has begun it continues in a cyclic manner unless arrested by the ability of chondrocytes to synthesise sufficient matrix components. Treatment should ideally be directed to this end.
Correlation between anion gap, blood L lactate concentration and survival in horses
Authors: GOSSETT K. A. , CLEGHORN BILDE , MARTIN G. S. , CHURCH GABIE E.
Published: April 2010

Blood L lactate concentration and anion gap were measured in 32 horses suspected of having metabolic acidosis. There was good linear correlation between these variables (r = 0,90791, P<0.0001) and both were good prognostic indicators. Anion gap was a good indicator of the presence but not the severity of L lactic acidosis and was a slightly better prognostic indicator. The ability to predict survival was not improved by the measurement of L lactate in addition to anion gap.
Antimicrobial selection and dosage in the treatment of equine bacterial infections
Authors: BAGGOT J. DESMOND , PRESCOTT J. F.
Published: April 2010

The success of antimicrobial therapy depends on administration of an agent to which the pathogenic microorganisms are susceptible at the concentrations attained at the site of infection. The route of administration, size of the dose and dosing interval must be appropriate for the drug preparation selected. With penicillins in particular, dosage can be tailored to the severity of the infection and quantitative susceptibility of the microorganism. This approach cannot be applied to aminoglycosides because their relatively narrow margin of safety limits the amount which can be administered. In severe infections it is important quickly to establish effective antimicrobial concentrations, which means that the choice of drug must be based on experience in treating the particular type of infection (empiric selection) and its dosage be adequate to produce a high peak concentration in the plasma. In treating septicaemic conditions of neonatal foals the deficit in serum immunoglobulins should be corrected, and it is advisable to administer antimicrobial agents or combinations that produce a bactericidal effect at dosages modified for immature physiological processes.
Treatment of radial fractures in adult horses: An analysis of 15 clinical cases
Authors: AUER J. A. , WATKINS J. P.
Published: April 2010

Fifteen cases of radial fractures in adult horses weighing more than 300 kg are discussed. Four of the horses were destroyed on humane grounds immediately because of a poor prognosis and expense of internal fixation; and two horses at five days and five weeks, respectively after treatment by cast application was initiated. Internal fixation was used in nine horses but of these only two horses recovered completely and resumed their former activities. In eight cases, two plates were applied, one lateral or medial and the other cranial. The internal fixation techniques of all nine horses were scrutinised and suggestions made for the future treatment of radial fractures. These suggestions are (1) the use of ASIF 5.5 mm cortical bone screws using the total width or thickness of the bone in each case. (2) Application of the dynamic condylar screw with its plate in distal or proximal fractures to allow more support. (3) Incorporation of a cancellous bone graft to the fracture. (4) Possible table recovery to prevent breakdown of the fixation during recovery. It is important that bone plates are applied over the total length of the bone. The fact that only two out of 15 horses survived and recovered completely underlines the problems associated with treatment of radial fractures in the adult horse.
Serological study of leptospiral infections and endogenous uveitis among horses and ponies in the United Kingdom
Authors: MATTHEWS A. G. , PALMER M. F.
Published: April 2010

The prevalence of antibody titres to a range of 20 leptospira antigens in the serum of horses and ponies with no ophthalmic abnormalities and with ophthalmoscopic evidence of endogenous uveal inflammatory disease was determined using a microscopic agglutination technique. Titres against leptospira antigens were observed in 13 out of 138 (9.1 per cent) animals with no ophthalmic abnormalities, and in three out of 27 (11.1 per cent) animals with anterior uveitis. Serovar sejroe was common to all seropositive animals with anterior uveitis. The results show that leptospira infection is not a major factor in the aetiology of equine anterior uveitis in the UK, but suggests that the organism may be associated with some cases of recurrent anterior uveitis.
Exercise‐induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. III. Subgross findings in lungs subjected to latex perfusions of the bronchial and pulmonary arteries
Authors: O'CALLAGHAN M. W. , PASCOE J. R. , TYLER W. S. , MASON D. K.
Published: April 2010

Latex was injected under pressure into bronchial and pulmonary arteries of the inflated lungs of Thoroughbreds and transverse sections taken to calculate the area of lesions resulting from exercise‐induced pulmonary haemorrhage. Extensive areas of dense brown haemosiderin varying from 0 to 45 per cent of total lung volume were identified, predominantly in the dorsocaudal lungfields. Bronchial arterial proliferation appeared to have replaced the pulmonary supply in affected areas of the lung. Closely associated with the staining and bronchial arterialisation, there was widespread small airway disease. The most severely affected bronchioles contained thick gelatinous or mucous exudate or mucoid plugs and had grossly thickened walls. These lesions suggest that the source of haemorrhage in exercise‐induced pulmonary haemorrhage is from alveolar capilliaries anomalously supplied by the bronchial arterial circulation through the development of pathological shunts. Small airway disease is suggested as being of major importance in the pathogenesis of the disease and may have led to the initial proliferation of the bronchial circulation.
Exercise‐induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. VI. Radiological/pathological correlations
Authors: O'CALLAGHAN M. W. , PASCOE J. R. , O'BRIEN T. R. , HORNOF W. J. , MASON D. K.
Published: April 2010

This study was initiated to determine if the extent and intensity of lung lesions associated with exercise‐induced pulmonary haemorrhage (EIPH) in horses could be predicted from thoracic radiographs. Sets of thoracic radiographs from 24 horses with varied histories of EIPH were subjectively coded for radiographic quality, and perceived extent and intensity of diffuse interstitial opacity by three radiologists who had no knowledge of the corresponding autopsy results. Codes assigned from radiographs for the chosen parameters were compared with coded estimates of lung surface staining assigned at post mortem and volume measurements of haemosiderin deposits and bronchial arterial neovascularisation recorded from lung slices in separate studies. The non‐parametric Spearman rank correlation test was used to test for statistical significance. All radiographically coded estimates of lesion severity were positively correlated with post mortem measurements of actual lesion involvement, but only the correlation between coded estimates of lesion opacity versus haemosiderin deposits and bronchial artery neovascularisation were statistically significant (P <0.05). Correlations between radiographic codes for lesion extent versus haemosiderin deposits and neovascularisation were just beyond the level of significance (P >0.05<0.1). These findings indicate that there are graded, radiographically discernible increases in interstitial opacity related to actual lesion severity. However, under the conditions of the study, accurate prediction of lung pathology in individual cases based on radiographic criteria was precluded by the wide variance of the coded values. The authors believe that with good radiographic technique and careful criteria selection, satisfactory prediction of lesion severity in EIPH cases could be achieved.
Exercise‐induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. VIII. Conclusions and implications
Authors: O'CALLAGHAN M. W. , PASCOE J. R. , TYLER W. S. , MASON D. K.
Published: April 2010

This paper reviews a series of clinical, post mortem and imaging studies on exercise‐induced pulmonary haemorrhage (EIPH) performed on 26 Thoroughbred racehorses. Post mortem techniques included routine gross, subgross and histological examination; coloured latex perfusions of pulmonary and bronchial circulations; and microradiography and computerised tomography scans of lungs with contrast injected vasculature. The major lesions were multiple, separate and coalescing foci of moderately proliferative small airway disease accompanied by intense neovascularisation of the bronchial circulation. As a result of bronchial artery angiogenesis, the systemic circulation dominated the vascular supply of the air exchange structures in affected areas, producing an apparent left to right shunt. Extensive areas of sequestered haemosiderophages indicated previous haemorrhage from vessels apparently supplied by the bronchial arteries. Diffuse and focal parenchymal destruction and connective tissue reactions in affected areas were considered to be secondary to localised haemorrhage and macrophage‐induced damage. The aetiology of EIPH was not determined, but the multifocal, small airway‐centred lesions indicated that low grade bronchiolitis, possibly of viral origin, was a factor. Gravitational effects also appear to contribute to dorsal distribution of the lesions. The mild focal and subclinical lesions confined to secondary lobules are thought to evolve into the serious lung pathology observed in EIPH cases through the effects of localised hypoxia induced by maximal exercise and partial airway obstruction. Once initiated, a vicious cycle of increasing inflammatory damage and further local bleeding is set in motion.
A review of environmental and host factors in relation to equine respiratory disease
Authors: CLARKE A. F.
Published: April 2010

This paper reviews the environmental and host factors which interact to affect the incidence and severity of episodes of respiratory disease in stabled horses. The folly of accepting housing criteria and management practices for the horse, based on direct extrapolations from intensive housing of meat producing animals, is discussed. The factors which affect air hygiene and physical environment of stables are considered in terms of short‐term athletic performance and long‐term welfare.
Cellular content of secretions obtained by lavage from different levels of the equine respiratory tract
Authors: MAIR T. S. , STOKES C. R. , BOURNE F. J.
Published: April 2010

Lavage procedures were used to obtain samples of respiratory secretions from the nasal cavity, trachea, bronchi and bronchoalveolar level of apparently normal conscious horses, and the cellular composition of the lavage fluids was assessed. There was a progressive increase in total cell count of the secretions obtained from the upper to the lower respiratory tracts. Nasal lavage fluid was composed chiefly of epithelial cells, whereas tracheal, bronchial and bronchoalveolar fluids contained higher proportions of macrophages, lymphocytes and neutrophils. Eosinophils and mast cells were identified in small numbers. The results of the differential cell counts were compared with previous published reports, which revealed some major differences between studies. It is suggested that these differences may relate to variations in the collection technique, the cytological interpretation of cell types, the presence of subclinical airway disease, and the degree of exposure to airborne environmental contaminants.
Outcome of treatment in 35 cases of guttural pouch mycosis
Authors: GREET T. R. C.
Published: April 2010

This paper describes the outcome of treatment of 30 cases of guttural pouch mycosis by ligation of the internal carotid artery on the cardiac side of the lesion and lavage of the affected pouch with natamycin. Twenty‐three horses recovered fully following this treatment while laryngeal hemiplegia persisted in one case and slight dysphagia caused by pharyngeal hemiplegia in another. The remaining five horses died or were destroyed. Five horses with guttural pouch mycosis, which had shown no epistaxis but had pharyngeal hemiplegia, were treated by topical natamycin alone. Only two of these survived, of which one remained slightly dysphagic. Ligation of the internal carotid artery of the cardiac side of the lesion is an effective means of reducing the chance of fatal epistaxis in cases of guttural pouch mycosis. Some cases of pharyngeal hemiplegia can make a complete recovery althouhh it may take 12 to 18 months.
Vascular malformations and angiomatous lesions in horses: A review of 10 cases
Authors: PLATT H.
Published: April 2010

Vascular malformations and angiomas are rather uncommon in horses and the literature concerning these lesions is reviewed. The pathology is described in 10 additional cases. These lesions were classified as arteriovenous malformation (one case), haemangiomas (six cases), ‘proliferative angiomas’ (two cases) and lymphangioma (one case). The haemangiomas and lymphangioma were probably hamartomatous in origin. Both cases of ‘proliferative angioma’ developed in aged animals and their pathogenesis was uncertain. More information is needed on the natural history and behaviour of lesions of this type.
Observations on equine strongyle control in southern temperate USA
Authors: REINEMEYER R. , HENTON J. E.
Published: April 2010

A program of rotational anthelmintic treatments at eight‐week intervals had failed to provide satisfactory equine strongyle control at a stable in southern USA. Anthelmintic resistance had rendered benzimidazoles ineffective, and intervals between treatments with other drugs were too great to prevent environmental contamination with ova. Ivermectin treatments at eight week intervals or pyrantel pamoate treatments at four week intervals successfully reduced egg counts for the majority of the summer grazing period. In southern temperate USA, translation of strongyle ova to larvae was most efficient during autumn and winter. Minimal larval translation occurred during summer when meteorological conditions limited pasture infectivity as effectively as anthelmintic treatments.
Ventilation‐perfusion relationships in the standing horse: An inert gas elimination study
Authors: HEDENSTIERNA G. , NYMAN GÖREL , KVART C. , FUNKQUIST BERIT
Published: April 2010

The multiple inert gas elimination technique was adapted for use in the conscious standing horse. The modifications included increased infusion rate of the inert gases (30 ml/min), extended infusion time (60 mins) in order to reach steady state, and construction of a nose mask mixing box system for collection of expired gas. Eight adult horses with a mean weight of 454 kg and a mean age of 6.1 years were studied while standing under resting conditions. Ventilation was 65.2 litres/min and cardiac output measured by thermodilution 40.2 litres/min. Systemic and pulmonary artery mean pressures were 114 and 26 mmHg, respectively. Three horses showed a unimodal V̇A/Q̇ distribution centred upon a mean V̇A/Q̇ of one. Five horses had a bimodal distribution with an additional high V̇A/Q̇ mode comprising 2 to 18 per cent of ventilation. The mean logarithmic standard deviation of perfusion was 0.41. There was no perfusion of Mow' V̇A/Q̇ regions, but minor shunting on an average of 1 per cent was noted. Inert gas dead space (minus apparatus dead space) averaged 38 per cent of total ventilation. Arterial oxygen tension varied from 11 to 14 kPa and the mean arterial CO2 tension was 5.7 kPa. It is concluded that the standing horse in general has a good match between ventilation and perfusion but that some individuals display high V̇A/Q̇ regions, possibly explained by poor perfusion of upper lung regions.
Exploratory celiotomy for gastrointestinal disease in neonatal foals: A review of 20 cases
Authors: ADAMS RAGAN , KOTERBA ANNE M. , BROWN M. P. , CUDD T. C. , BAKER W. A.
Published: April 2010

The medical records of 20 neonatal foals in which exploratory celiotomies were performed for gastrointestinal disease were reviewed. In all 20 foals, persistent pain and/or progressive abdominal distension were the primary clinical findings influencing the decision to operate. However, ancilliary laboratory data were important to the proper medical management of these foals during anaesthesia and following surgery. Surgical diagnoses of the 20 foals included ileus (nine foals; 45 per cent), small colon obstruction (five foals; 25 per cent), large colon displacement (three foals; 15 per cent), small intestinal displacement (two foals; 10 per cent), and perforated gastric ulcer (one foal; 5 per cent). Seventeen foals were recovered from anaesthesia, 13 of these were discharged from the hospital, seven were alive six months or more following discharge. Sepsis was the cause of death in six of the 10 foals that died following recovery.
The use of H(orse) INDEX: A method of analysing the ground reaction force patterns of lame and normal gaited horses at the walk
Authors: MERKENS H. W. , SCHAMHARDT H. C. , HARTMAN W. , KERSJES A. W.
Published: April 2010

The amplitudes, impulses and times of occurrence of a number of selected peaks in the ground reaction force tracings of 17 horses with various clinical histories were compared with those of 20 horses used to establish values for the ‘standard’ Dutch Warm blood horse. The resulting factors were combined, using different weighting factors, into indices characterising each limb. The symmetry between the loading of the forelimbs and the hindlimbs was used to calculate amplitude and peak‐time symmetry indices. Limb and symmetry indices were combined in one H(orse) INDEX. This method of quantifying the ground reaction force pattern, together with appropriate graphic display of the tracings, was useful in clinical evaluation of force plate measurements.
Body condition scoring and weight estimation of horses
Authors: CARROLL C. L. , HUNTINGTON P. J.
Published: April 2010

Three hundred and seventy two horses of varying breeds, height and fatness were weighed and measured for height at the withers. They were assessed for condition score by adaptation of a previously published method. The heart girth and length of 281 of the horses were also measured. Weight of horses was highly correlated (P < 0.001) with height (r2=0.62), condition score (r2=0.22) and girth2× length (r2=0.90). Nomograms were constructed to predict weight from height and condition score, and girth and length measurements. Weight can also be accurately estimated from the formula:‐

The average value of Y' in this experiment was 11900 and this estimated weight with more accuracy than some previously published values of ‘Y’. Racing Thoroughbred horses were found to be significantly lighter than non‐racing Thoroughbreds of the same height and condition score. The method of assessment of condition score was shown to be repeatable between different operators with varying degrees of experience.
Distribution and ultrastructure of mast cells in the equine respiratory tract
Authors: MAIR T. S. , STOKES C. R. , BOURNE F. J.
Published: April 2010

Mast cells in the equine respiratory mucosa were studied at both light — and transmission electron — microscope levels. Mast cells were identified at all levels of the tract, with the greatest cell density in the nasopharynx. The majority (57 to 94 per cent) of this cell population were located within the connective tissue of the lamina propria. Up to 20 per cent of these cells were associated with the mucosal glandular tissue, whilst small numbers were present within the surface epithelium and in association with nodular lymphoid tissue. In the peripheral lung tissue 20 per cent of the mast cell population was associated with the small airways, 25 per cent with the pleura, and 32 per cent with blood vessels. The fine and ultrastructural features of these mast cells resemble those described in other species, and their granules consist of two types which resemble human mast cells.
The effects of high intensity exercise on the plasma concentration of lactate, potassium and other electrolytes
Authors: HARRIS PATRICIA , SNOW D. H.
Published: April 2010

To study the effect of short term high intensity exercise on plasma lactate, potassium, sodium and chloride concentrations, five Thoroughbred horses were galloped on a treadmill at a 5° incline. Following a standardised warm‐up period, they were galloped at 8, 10, or 12 metres/sec for 2 mins. One horse also galloped at 14 metres/sec for 1.5 mins. Sequential arterial and/or venous blood samples were collected during exercise and recovery. At 12 metres/sec, the effect of different recovery modes, ie, standing, walking or trotting, on the electrolytes was also examined. There was a progressive rise in plasma potassium concentration during galloping, with peak values occurring at the end of the exercise bout. In some cases, values above 10 mmol/litre were recorded at the highest workloads. Plasma lactate concentrations peaked during early recovery, with values up to 32 mmol/litre. A high correlation existed between peak potassium and lactate concentrations (venous r=0.923, and arterial r=0.989). Following exercise there was a rapid return to baseline plasma potassium concentrations, but by 12 mins recovery there was still an elevated lactate concentration, the extent depending on the intensity of the exercise bout and the recovery mode. There was a small rise in plasma sodium but no significant change in plasma chloride concentrations during exercise. However, when adjusted for the decrease in plasma volume, as determined from total plasma protein concentration, there was a decrease in circulating amounts of both electrolytes.