bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clostridial myonecrosis in horses (37 cases 1985–2000)
Authors: PEEK S. F. , SEMRAD S. D. , PERKINS G. A. 
Published: April 2007

SummaryReasons for performing study: Previous reports of clostridial myonecrosis have either focused on individual case reports or have been small retrospective studies reporting very high mortality rates.Objectives: The objective of this study was to describe the outcome of cases of clostridial myonecrosis submitted to 2 referral equine hospitals in the United States over a 15 year period.Methods: A retrospective study of case material selected on the basis of positiveClostridiumspp. culture or the identification ofClostridiumspp. by specific fluorescent antibody testing from soft tissue wounds was performed at Cornell and Wisconsin.Results: 37 cases of clostridial myonecrosis were documented. Twenty‐seven horses survived, 8 were subjected to euthanasia and 2 died during treatment for an overall survival rate of 73%. Twenty‐five cases (68%) were associated withClostridium perfringensalone, 6 cases (16%) withCl. septicumalone, 4 cases with mixed clostridial infections (11%), 1 case withCl. sporogenesand 1 with an unspeciatedClostridiumspp. The highest survival rate of 81% was docum ented for those cases from whichCl. perfringensalone was isolated. The most common antecedent condition prior to referral was colic. The myonecrotic lesion occurred within 6–72 h of a soft tissue injection in 34 cases but was associated with a wound or laceration in the remaining 3 cases. Of the 34 cases associated with recent injections, 24 were associated with i.m. injections in the cervical region, 4 in thesemimembranosus/semitendinosusregion, 3 in the gluteal region, 2 with perivascular leakage of drugs administered into the jugular vein and 1 case developed simultaneously in the gluteal and neck region following injections at both sites.Conclusions: Clostridial myonecrosis can occur following the i.m. or inadvertent perivascular administration of a wide variety of commonly administered drugs. It is most common in the neck musculature. Aggressive treatment can be associated with survival rates of up to 81% for cases due toCl. perfringensalone. Survival rates for otherClostridialspp. tend to be lower.Potential relevance: A combination of high dose i.v. antibiotic therapy and surgical fenestration/debridement is the best approach to cases of clostridial myonecrosis. With rapid diagnosis and therapeutic intervention, horses may have up to an 81% chance of survival.
Pharmacokinetics of fentanyl following intravenous and transdermal administration in horses
Authors: MAXWELL L. K. , THOMASY S. M. , SLOVIS N. , KOLLIAS‐BAKER C. 
Published: April 2007

SummaryReasons for performing study: Although fentanyl has been reported to cause CNS excitation in horses, a transdermal therapeutic system (TTS) containing this mu agonist has recently been used empirically in equine medicine to treat moderate to severe pain. A better understanding of the disposition of fentanyl following transdermal administration would facilitate the clinical use of TTS fentanyl to obtain analgesia in horses.Objectives: To determine the pharmacokinetics of fentanyl following i.v. and TTS patch administration in healthy, mature horses and to evaluate the tolerance of horses to TTS fentanyl administration.Methods: The pharmacokinetics of fentanyl in serum were assessed following a single i.v. dose, a single TTS dose, and multiple TTS doses in 6 healthy horses. Physical examinations, haematology and serum biochemistry analyses during transdermal fentanyl application were then performed to determine tolerance of continuous fentanyl administration.Results: Fentanyl was very rapidly and completely absorbed following a single TTS dose. Mean serum fentanyl concentrations consistent with analgesia in other species were reached by 1 h and maintained until 32 h after patch application. Similar steady state serum concentrations were obtained when multiple doses of TTS fentanyl were administered every 48 or 72 h over 8 or 9 days, with less fluctuation in serum concentrations during the 48 h dosing interval. Three horses exhibited brief (<12 h) episodes of increased body temperature; however, transdermal fentanyl administrations were not associated with other significant changes in haematology and biochemistry panels or physical examination findings.Conclusions and potential relevance: Although the pharmacodynamics of fentanyl have not been investigated fully in horses, transdermally‐administered fentanyl exhibited a favourable pharmacokinetic profile without clinically relevant side effects and may be a useful analgesic in equine patients.
Airway inflammation and mucus in two age groups of asymptomatic well‐performing sport horses
Authors: GERBER V. , ROBINSON N. E. , LUETHI S. , MARTI E. , WAMPFLER B. , STRAUB R. 
Published: April 2007

SummaryReasons for performing study: Horses housed in conventional stable environments are exposed to high dust loads. Longterm exposure to inhaled dust may lead to subclinical airway disease.Hypotheses: Airway inflammation and mucus accumulation are 1) common in asymptomatic well‐performing sport horses, 2) increased in older compared to younger individuals and 3) correlated.Methods: Mucus quantity and quality (endoscopic scoring) and BALF differential cytology were assessed in 13 younger horses (mean age 5 years) and 13 older horses (mean age 15 years), which had no historical or clinical evidence of lower airway disease, were performing well and were housed permanently in a conventional stable environment.Results: 1) Airway inflammation and/or mucus accumulation were very common. All sport horses showed evidence of subclinical inflammatory airway disease (IAD). 2) Older horses, having been exposed for 10 more years to a conventional stable environment, did not show increased subclinical airway inflammation or mucus accumulation. The only differences between the age groups were increased BALF total and lymphocyte cell counts in the younger horses. 3) Mucus quantity and quality scores were not significantly correlated with each other or with BALF neutrophil percentages and absolute numbers.Conclusions: Although clinically healthy and performing well, all of the examined horses housed in a conventional stable environment showed evidence of IAD. The degree of IAD was not increased in older horses that had not developed clinical signs.Potential relevance: The effect of subclinical degrees of IAD on performance in dressage and show jumping should be investigated further to better understand the clinical significance of IAD in sport horses.
Comparison of hamster and pony challenge models for evaluation of effect of antigenic drift on cross protection afforded by equine influenza vaccines
Authors: DALY J. M. , YATES P. J. , BROWSE G. , SWANN Z. , NEWTON J. R. , JESSETT D. , DAVIS‐POYNTER N. , MUMFORD J. A. 
Published: April 2007

Summary Reasons for performing study: Vaccination and challenge studies in ponies are the most relevant experimental system for predicting whether strains included in equine influenza vaccines are relevant, but they are difficult to perform. Objectives: In order to investigate the feasibility of using a small animal model, results of a cross‐protection study in hamsters were compared with those from a previous pony challenge experiment. Methods: Animals were immunised with inactivated vaccines containing one of 4 strains of equine influenza A H3N8 subtype virus isolated over a 26 year period (1963 to 1989), then challenged with a 1989 strain. Results: Although there was no significant difference in titres of excreted virus between groups of vaccinated ponies, hamsters immunised with heterologous strains had significantly higher virus titres in the lung than hamsters vaccinated with the homologous strain. In both ponies and hamsters, the number of animals excreting virus was greater the earlier the isolation date of the vaccine strain, although this was only significant in the hamster study. Conclusions: Despite differences, the overall conclusion of both the pony and hamster models was that heterologous vaccines may be less effective than homologous vaccines at preventing virus excretion. Potential relevance: Further validation is required, but the hamstermodel shows potential for preliminary assessment of the effects of antigenic drift on vaccine efficacy.
The effects of local anaesthetic solution in the navicular bursa of horses with lameness caused by distal interphalangeal joint pain
Authors: SCHUMACHER JOHN , SCHUMACHER JIM , GILLETTE R. , DEGRAVES F. , SCHRAMME M. , SMITH R. , PERKINS J. , COKER M. 
Published: April 2007

SummaryReasons for performing study: Analgesia of the palmar digital (PD) nerves has been demonstrated to cause analgesia of the distal interphalangeal (DIP) joint as well as the sole. Because the PD nerves lie in close proximity to the navicular bursa, we suspected that that analgesia of the navicular bursa would anaesthetise the PD nerves, which would result in analgesia of the DIP joint.Objectives: To determine the response of horses with pain in the DIP joint to instillation of local anaesthetic solution into the navicular bursa.Methods: Lameness was induced in 6 horses by creating painful synovitis in the DIP joint of one forefoot by administering endotoxin into the joint. Horses were videorecorded while trotting, before and after induction of lameness, at three 10 min intervals after instilling 3.5 ml local anaesthetic solution into the navicular bursa and, finally, after instilling 6 ml solution into the DIP joint. Lameness scores were assigned by grading the videorecorded gaits subjectively.Results: At the 10 and 20 min observations, median lameness scores were not significantly different from those before administration of local anaesthetic solution into the navicular bursa (P≥0.05), although lameness scores of 3 of 6 horses improved during this period, and the 20 min observation scores tended toward significance (P = 0.07). At the 30 min observation, and after analgesia of the DIP joint, median lameness scores were significantly improved (P≤0.05).Conclusions: These results indicate that pain arising from the DIP joint can probably be excluded as a cause of lameness, when lameness is attenuated within 10 mins by analgesia of the navicular bursa.Potential relevance: Pain arising from the DIP joint cannot be excluded as a cause of lameness when lameness is attenuated after 20 mins after analgesia of the navicular bursa.
Homeostasis of intracellular Ca2+ in equine chondrocytes: response to hypotonic shock
Authors: WILKINS R. J. , AFAIRFAX T. P. , DAVIES M. E. , MUZYAMBA M. C. , GIBSON J. S. 
Published: April 2007

Summary Reasons for performing study: Ca2+ homeostasis in articular chondrocytes affects synthesis and degradation of the cartilage matrix, as well as other cellular functions, thereby contributing to joint integrity. Although it will be affected by mechanical loading, the sensitivity of intracellular Ca2+ concentration ([Ca2+]i) in equine articular chondrocytes to many stimuli remains unknown. Hypothesis: An improved understanding of Ca2+ homeostasis in equine articular chondrocytes, and how it is altered during joint loading and pathology, will be important in understanding how joints respond to mechanical loads. Methods: [Ca2+]i was determined using the fluorophore fura‐2. We examined the effects of hypotonic shock, a perturbation experienced in vivo during mechanical loading cycles. We used inhibitors of Ca2+ transporters to ascertain the important factors in Ca2+ homeostasis. Results: Under isotonic conditions, [Ca2+]i was 148 ± 23 nmol/l, increasing by 216 ± 66 nmol/l in response to reduction in extracellular osmolality of 50%. Resting [Ca2+]i, and the increase following hypotonic shock, were decreased by Ca2+ removal; they were both elevated when extracellular [Ca2+] ([Ca2+]o) was raised or following Na+ removal. The hypotonicity‐induced rise in [Ca2+]i was inhibited by exposure of cells to gadolinium (Gd3+; 10 μmol/l), an inhibitor of mechanosensitive channels. [Ca2+]i was also elevated following treatment of cells with thapsigargin (10 μmol/l), an inhibitor of the Ca2+ pump of intracellular stores. Conclusions: A model is presented which interprets these findings in relation to Ca2+ homeostasis in equine articular chondrocytes, including the presence of mechanosensitive channels allowing Ca2+ entry, a Na+/Ca2+ exchanger for removal of intracellular Ca2+ and intracellular stores sensitive to thapsigargin. Potential relevance: A more complete understanding of Ca2+ homeostasis in equine chondrocytes may allow development of future therapeutic regimes to ameliorate joint disease.
A survey of equine abortion, stillbirth and neonatal death in the UK from 1988 to 1997
Authors: SMITH K. C. , BLUNDEN A. S. , WHITWELL K. E. , DUNN K. A. , WALES A. D. 
Published: April 2007

SummaryReasons for performing study: A detailed review of laboratory records for equine abortion is fundamental in establishing current disease trends and suggesting problems important for further research.Objectives: To review the causes of abortion and neonatal death in equine diagnostic submissions to the Animal Health Trust over a 10 year period.Methods: The diagnoses in 1252 equine fetuses and neonatal foals were reviewed and analysed into categories.Results: Problems associated with the umbilical cord, comprising umbilical cord torsion and the long cord/cervical pole ischaemia disorder, were the most common diagnoses (38.8%: 35.7% umbilical cord torsion and 3.1% long cord/cervical pole ischaemia disorder). Other noninfective causes of abortion or neonatal death included twinning (6.0%),intrapartumstillbirth (13.7%) and placentitis, associated with infection (9.8%).E. coliandStreptococcus zooepidemicuswere the most common bacteria isolated. Neonatal infections not associated with placentitis accounted for 3.2% of incidents; and infections with EHV‐1 or EHV‐4 for 6.5%.Conclusions: Definitive diagnosis of equine abortion is possible in the majority of cases where the whole fetus and placenta are submitted for examination.Potential relevance: Given the high incidence of umbilical cord torsion and related problems as causes of abortion in UK broodmares, more research on factors determining umbilical cord length and risk of torsion is essential.
Evaluation of Carolina Rinse solution as a treatment for ischaemia reperfusion of the equine jejunum
Authors: Dabareiner R. M. , II N. A. White , Donaldson L. 
Published: April 2007

SummaryReasons for performing study: Ileus and peritoneal adhesions are the most common complications following surgery for small intestinal obstruction. Carolina Rinse (CR) has been shown to decrease reperfusion injury in intestine and other organs.Hypothesis: CR decreases intestinal inflammation and subsequent scarring associated with reperfusion injury.Methods: CR was infused intra‐arterially and applied topically just prior to reperfusion in jejunum exposed to experimental ischemia. Vascular permeability, neutrophil accumulation and serosal scarring were compared in treated and untreated intestine.Resultls: CR maintained a normal osmotic reflection coefficient and decreased migration of neutrophils into the serosa during reperfusion. After 10 days, treated intestine was normal in appearance with a trend toward less serosal scarring and fibroblast proliferation. There was a significant decrease in fibroplasia at biopsy sites in treated intestine.Conclusions: Arterial perfusion combined with topical application of CR during jejunal ischaemia decreases immediate reperfusion injury and limits post operative scarring.Potential relevance: CR should be used as a local perfusate rather than a systemic treatment; it may best be applied topically and intraluminally to avoid damaging mesenteric arteries. CR should be considered an adjunct treatment as part of overall surgical management and post operative care.
Long‐term survey of laryngoplasty and ventriculocordectomy in an older, mixed‐breed population of 200 horses. Part 1: Maintenance of surgical arytenoid abduction and complications of surgery
Authors: DIXON P. M. , McGORUM B. C. , RAILTON D. I. , HAWE C. , TREMAINE W. H. , DACRE K. , McCANN J. 
Published: April 2007

SummaryReasons for performing study: Laryngoplasty (LP) is currently the most common surgical treatment for equine laryngeal paralysis, however, there have been no reports quantifying the degree of retention of arytenoid abduction following L P. ADitionally, the complications of LP have been poorly documented.Objectives: To record the degree of arytenoid abduction retention following LP and to accurately document all complications of surgery.Methods: A study (1986–1998) of 200 horses of mixed breed and workload, median age 6 years (prospective 136 cases and retrospective 64 cases) undergoing LP (using 2 stainless steel wires) and combined ventriculocordectomy was undertaken; 198 owners completed questionnaires, a median of 19 months following surgery. The degree of arytenoid abduction achieved was endoscopically, semi‐quantitatively evaluated using a 5‐grade system, at 1 day, 7 days, and 6 weeks after surgery.Results: On the day following LP, 62% of horses had good (mediangrade2) arytenoid abduction, 10% had excessive (grade1), and 5% had minimal (grade4) abduction (overall ‐ mediangrade2). Due to progressive loss of abduction, moderate (mediangrade3, range 1–5) abduction was present overall at 1 and 6 weeks after LP. Further surgery was required to re‐tighten prostheses in 10% of cases with excessive loss of abduction, or to loosen prostheses in 7% of horses which had continuing high levels of LP abduction and significant post operative dysphagia. LP wound problems (mainly seromas and suture abscesses) were reported to last <2 weeks in 9% of cases, <4 weeks in 4% and >4 weeks in 4%. The (partially sutured) laryngotomy wounds discharged post operatively for <2 weeks in 22% of cases, <4 weeks in 7% and for >4 weeks in 2%. Coughing occurred at some stage post operatively in 43% of cases and its presence correlated significantly with the degree of surgical arytenoid abduction. This coughing occurred during eating in 24% of cases and was not associated with eating (or dysphagia) in the other 19% of cases. Chronic (>6 months duration) coughing occurred in 14% of cases, but appeared to be due to intercurrent pulmonary disease in half of these horses.Conclusions: Suturing the cricotracheal membrane allows most laryngotomy wounds to heal quickly. Laryngoplasty wound problems were of little long‐term consequence when stainless steel wire prostheses were used.Potential relevance: A significant loss of LP abduction occurs in most horses in the 6 weeks following surgery and efforts should be made to find ways to prevent such loss. However, excessive LP abduction is associated with post operative dysphagia and coughing.
The application of a scintigraphic grading system to equine tibial stress fractures: 42 cases
Authors: RAMZAN P. H. L. , NEWTON J. R. , SHEPHERD M. C. , HEAD M. J. 
Published: April 2007

Summary Reasons for performing study: Tibial stress fractures are an important cause of lameness in the Thoroughbred racehorse. While it is recognised that these injuries can vary in clinical presentation and radiographic or scintigraphic appearance, little has been done to quantify lesion severity. By contrast the scintigraphic grading of tibial stress fractures in human athletes is widely reported and assists in the selection of appropriate management regimes. Objectives: To determine the relationship between scintigraphic grade, clinical severity and radiographic appearance of tibial stress fractures. Methods: The current study involved the retrospective analysis of records from 42 Thoroughbreds with abnormal tibial scintigraphic activity. Results: There was a significant association between lesion site and scintigraphic grade and good correlation of scintigraphic scoring between investigators. No significant association was found between scintigraphic grade and either radiographic grade or degree of lameness. Conclusions: The study confirmed that radiographic appearance is an unreliable measure of clinical severity or stage of progression of lesions. The scintigraphic grading system used in the study was not of use in defining stress fracture severity in the equine tibia. Potential relevance: Despite this finding, there is clearly a need for prospective investigations to explore the potential for targeted management regimes for tibial injuries based on lesion site or clinical criteria.
Efficacy of trilostane for the treatment of equine Cushing's syndrome
Authors: McGOWAN C. M. , NEIGER R. 
Published: April 2007

SummaryReasons for performing study: Trilostane, a competitive 3‐beta hydroxysteroid dehydrogenase inhibitor, has been used successfully to control clinical signs and cortisol excess in canine pituitary dependent hyperadrenocorticismObjectives: Trilostane was evaluated for its efficacy in resolving clinical and clinicopathological abnormalities of equine Cushing's syndrome (ECS) and to assess its safety.Methods: Twenty horses (mean age 21 years) diagnosed with ECS were followed for 1 or 2 years. Affected horses received 0.4–1 mg/kg (mean 0.5 mg/kg) trilostane once daily.Results: Clinical signs assessed over 1 or 2 years, showed a reduction in lethargy in all horses post treatment. Polyuria and/or polydipsia, present in 11 horses, was reduced in all after treatment. Recurrent or chronic laminitis, present in 16 horses, improved in 13/16 (81%) of cases. There were no side effects reported. Combined dexamethasone suppression and thyrotropin releasing hormone (TRH) stimulation tests were significantly different before and 30 days following therapy. There was a significant reduction (P = 0.01) of cortisol following TRH administration before (160 ± 53.0 nmol/l) and after (130 ± 46.1 nmol/l) trilostane.Conclusions: Trilostane caused improvement in clinical signs in horses, without side effects, and a corresponding decrease in cortisol response to TRH administration.Potential relevance: Trilostane may be a useful therapy for the treatment of ECS. Further work comparing the effects of trilostane and pergolide is warranted.