bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress response to chronic inflammation in the horse
Authors: MILLS P. C. , NG J. C. , KRAMER H. , AUER D. E. 
Published: April 2010

SummaryFive clinically healthy Thoroughbred geldings were injected with Freund's adjuvant 3 times to induce a chronic inflammatory response. Blood was collected at various times before and after adjuvant administration. Clinical responses (rectal temperature and general demeanour) were also monitored. Adjuvant injection induced increases in rectal temperature and plasma fibrinogen concentration (maximum levels measured were mean ± s.d. 39.7 ± 0.5°C and 8.2 ± 03 g/l, respectively), indicative of an inflammatory response. A mild clinical depression was also observed in the horses for 24 h after the first injection of adjuvant only. Plasma Cortisol levels decreased significantly from control levels of mean ± s.d. 187.7 ± 24.3 nmol/l to a minimum of 80.2 ± 22.1 nmol/l (P<0.01) 9 days after the first injection of adjuvant. Conversely, plasma insulin levels increased after the first injection of adjuvant to a maximum (96.7 ± 15.2 iu/ml; P<0.01) 12 days later, while plasma glucose concentrations tended to decline. A control group of horses to rule out contemporary environmental influences on the physiological and biochemical indices measured was not included in this study. The results show that chronic inflammation in the horse depressed resting plasma Cortisol concentrations.
Enostosis‐like lesions in the long bones of 10 horses: scintigraphic and radiographic features
Authors: BASSAGE L. H. , ROSS M. W. 
Published: April 2010

SummaryTen horses admitted for lameness evaluation including bone scintigraphy had enostosis‐like lesions, described scintigraphically as focal or multifocal areas of intense increased radioisotope uptake within the medullary cavity of one or more long bones, and radiographically as one or multiple round to irregularly shaped radiopacities within the medullary cavity, often in close proximity to the nutrient foramen. There were 6 Thoroughbreds, one male, one female and 4 geldings, 3 Standardbreds, all geldings and one Appaloosa gelding; age 3–10 years. Enostosis‐like lesions were seen in the tibia (5 horses), radius (3 horses), humerus (one horse) and third metatarsal bone (MT‐III) (4 horses). The number of affected bones in each horse was 1–3. Of 16 affected limbs, there were 9 hindlimbs and 7 forelimbs. Enostosis‐like lesions were considered a possible cause of lameness in 5 horses, but were considered incidental findings in the other horses. Lesions thought to cause lameness were seen in the tibia (2 horses), MT‐III (one horse) and in the radius (4 horses). Lameness resolved after horses were rested (2–6 months) and given nonsteroidal anti‐inflammatory drugs (4 horses). Follow‐up scintigraphic examination in 3 horses (2, 6 and 9 months later, respectively) revealed normal radioisotope uptake in the affected areas.
Quantification of exercise‐induced pulmonary haemorrhage with bronchoalveolar lavage
Authors: MEYER T. S. , FEDDE M. R. , GAUGHAN E. M. , LANGSETMO I. , ERICKSON H. H. 
Published: April 2010

SummaryExercise‐induced pulmonary haemorrhage (EIPH) causes serious economic losses in the horse racing industry. Endoscopic examination indicates that 40–90% of horses exhibit EIPH following sprint exercise, but the limitations of the endoscope prevent diagnosis in many horses. Bronchoalveolar lavage (BAL) was utilised to detect red blood cells (RBCs) in the terminal airways in 6 horses. Two lavages were performed at weekly intervals prior to exercise, one within 90 min after exercise, and 5 at weekly intervals after exercise. The horses were exercised strenuously at 12.5–14.6 m/s on a treadmill (3 degree incline). Heart rates ranged from 192–207 beats/min, and mean pulmonary arterial pressures (mPAP) ranged from 80–102 mmHg. Neither epistaxis nor endoscopic evidence of EIPH was seen in any of the 6 horses following exercise. However, the number of RBCs in the lavage fluid increased significantly over control values immediately after exercise in all horses but returned to control values by one week after exercise.Haemosiderophages in the BAL fluid did not increase until one week after exercise and remained elevated for 3 weeks after exercise. Twenty per cent of the total population of alveolar macrophages contained haemosiderin. A positive relationship occurred between the number of RBCs in the lavage fluid and mPAP; the amount of haemorrhage increased as the mPAP exceeded 80 to 90 mmHg. The results with BAL used as the diagnostic tool, suggest that all strenuously exercised horses may exhibit EIPH; the amount of haemorrhage appears to be associated with the magnitude of the high pulmonary arterial pressure.
Absence of detectable pharmacological effects after oral administration of isoxsuprine
Authors: HARKINS J. D. , MUNDY G. D. , STANLEY S. , WOODS W. E. , SAMS R. A. , RICHARDSON D. R. , GRAMBOW S. C. , TOBIN T. 
Published: April 2010

SummaryIsoxsuprine is reported to be a peripheral vasodilator used in human and veterinary medicine to treat ischaemic vascular disease. In horses, it is generally administered orally to treat navicular disease and other lower limb problems. To define the scope and duration of its pharmacological responses after oral administration, 6 horses were dosed with isoxsuprine HCl (1.2 mg/kg bwt) q. 12 h for 8 days and then tested to assess the duration and extent of pharmacological actions. There was no significant difference between isoxsuprine and control treatment values for heart rate, spontaneous activity, sweat production, anal muscle tone, core and skin temperatures, and cutaneous blood flow. The lack of pharmacological effect following oral administration was in sharp contrast to the marked response following i.v. dosing reported in earlier experiments.
Effect of intravenous lidocaine on halothane minimum alveolar concentration in ponies
Authors: DOHERTY T. J. , FRAZIER DONITA L. 
Published: April 2010

SummaryThis study investigated the effect of lidocaine i.v. on halothane minimum alveolar concentration (MAC) in ponies. Six ponies were anaesthetised with thiopentone and succinylcholine, intubated and anaesthesia maintained with halothane. Ventilation was controlled and blood pressure maintained within clinically acceptable limits. Following a 2 h equilibration period, baseline halothane MAC was determined. The ponies were then given a loading dose of lidocaine (2.5 or 5 mg/kg bwt) or saline over 5 min, followed by a constant infusion of lidocaine (50 or 100 μg/kg/min, or saline, respectively). The halothane MAC was redetermined after a 60 min infusion of lidocaine or saline. The baseline halothane MAC for the control group was mean ± s.d. 0.94 ± 0.03%, and no significant decrease occurred following saline infusion. Lidocaine decreased halothane MAC in a dose‐dependent fashion (r = 0.86; P<0.0003). The results indicate that i.v. lidocaine may have a role in equine anaesthesia.
Water and electrolyte intake and output in conditioned Thoroughbred horses transported by road
Authors: van den BERG J. S. , GUTHRIE A. J. , MEINTJES R. A. , NURTON J. P. , ADAMSON D. A. , TRAVERS C. W. , LUND R. J. , MOSTERT H. J. 
Published: April 2010

SummaryThe objectives of this trial were to measure the water and electrolyte intake and loss, of horses during road transportation in relatively hot environmental conditions. Six mature, Thoroughbred horses in full training were used in a balanced crossover design. The horses were conditioned on a treadmill for 6 weeks before the start of the trial in order to simulate the type of horse that is transported most often over long distances in South Africa. The horses were assigned randomly to one of 2 treatment groups. On a particular day 3 horses were transported, while the other horses served as controls. One month was allowed before the crossover. Horses in the ‘transport group’ were transported by tarred road in a circular route over 600 km. This allowed the standardisation of measurements and use of the same instruments in both groups. Data were collected in each treatment group during transportation that lasted for 8 h (transport phase) and for 6 h after travelling (recovery phase). The following data were collected or calculated: Water and electrolyte (sodium, potassium and chloride) intake and output, changes in bodyweight and feed consumption. Although water was always available, the transport group failed to drink during transit. Based on bodyweight, the transported horses were 3% dehydrated at the end of transit. This bodyweight loss was corrected within one hour after their return due to a significantly higher water intake compared to control horses. The feed intake in the transported horses was unaffected during travelling, but was decreased for 6 h following transportation. Urinary water loss was similar in the 2 treatment groups during and following transportation. The faecal water loss decreased in the transported horses and remained lower than the control group for 6 h following transit. Total sodium and chloride intake were unaffected, while the potassium intake was decreased during transportation. Sodium and potassium loss via the faeces and urine during the transport period were similar in the 2 treatment groups, whereas potassium output in the transport group was significantly decreased during the recovery period of the study. It was concluded that transportation by road affected the water and electrolyte balance of conditioned horses for a period up to 6 h after travelling.
Serum gentamicin concentrations in compromised neonatal foals
Authors: RAISIS A. L. , HODGSON J. L. , HODGSON D. R. 
Published: April 2010

SummaryTwenty‐one compromised neonatal foals hospitalised at the Rural Veterinary Centre (RVC) during 1993 were studied to determine i) serum gentamicin concentrations obtained when gentamicin was administered at 3.3 mg/kg bwt twice daily i.m.; ii) factors which contributed to inter‐foal variation in serum gentamicin concentrations achieved and iii) clinical efficacy of gentamicin therapy in foals with confirmed septicaemia. Septicaemia was confirmed in 7 foals with positive blood cultures and suspected in 8 foals with a sepsis score >11. Peak serum concentrations (Ps) were >6 μg/ml in all foals and >8 μg/ml in 60% of foals. Trough serum concentrations (Ts) were <2 μg/ml in all foals. Factors found to produce inter‐foal variation in the Ps achieved included age (<24 h; decreased), bodyweight (<38 kg; decreased) and severity of dehydration (8–12% bodyweight; increased). Clinical response was not associated with achievement of Ps >8 μg/ml, but was negatively influenced by the severity of clinical signs of depression. None of the foals in this study developed septic arthritis or pneumonia during or after therapy. No serum biochemical evidence (i.e. elevated serum creatinine concentrations) of gentamicin‐induced nephrotoxicity was noted during therapy.
Effect of cisapride on gastric emptying in horses following endotoxin treatment
Authors: VALK N. , DOHERTY T. J. , BLACKFORD J. T. , ABRAHA T. W. , FRAZIER DONITA L. 
Published: April 2010

SummaryThe effect of cisapride pretreatment on gastric emptying in horses was determined by measuring serum concentrations of acetaminophen, a drug known to be readily absorbed in the small intestine but not in the stomach. The time to reach maximum serum acetaminophen concentrations (Tmax), the maximum serum concentrations (Cmax) and the area under the serum acetaminophen concentration vs. time curves (AUC) were compared among treatment groups. In the first part of the study, the effect of orally administered cisapride (0.1, 0.2 and 0.4 mg/kg bwt) on gastric emptying was examined in 6 normal fasted horses. In the second part of the study, gastric emptying in horses given endotoxin i.v. (n = 6) was compared to those that received cisaprideper osprior to administration of endotoxin (n = 6) and those that received neither compound (n = 6). Cisapride did not alter gastric emptying in normal horses. Endotoxin caused a profound delay in gastric emptying and pretreatment with cisapride significantly attenuated this effect. It is concluded that cisapride may be useful as a prophylactic measure when administered prior to the development of endotoxaemia.
Environmental control to maintain stabled COPD horses in clinical remission: effects on pulmonary function
Authors: VANDENPUT SANDRINE , DUVIVIER DOMINIQUE H. , VOTION DOMINIQUE , ART TATIANA , LEKEUX P. 
Published: April 2010

SummaryThe objective of this study was to test the hypothesis that stabled COPD horses can be maintained in clinical remission by replacing hay by grass silage and bedding made of wood shavings(Period B)and of wheat straw(Period C)during 6 weeks, respectively. At the end of these different periods, the pulmonary function of the horses was assessed by mechanics of breathing and arterial blood analyses. These results were compared to those measured in clinical remission obtained after 2 months in pasture(Period A).No significant difference was observed between these 3 periods neither to values obtained for healthy horses placed during 6 weeks in a hay environment. For all that, COPD horses placed in contact with hay in the same barn developed within mean ± s.d. 8 ± 3 days clinical signs of heaves and significant alterations of pulmonary function parameters.
Equine ulcerative keratomycosis: visual outcome and ocular survival in 39 cases (1987–1996)
Authors: ANDREW S. E. , BROOKS D. E. , SMITH P. J. , GELATT K. N. , CHMIELEWSKI N. T. , WHITTAKER C. J. G. 
Published: April 2010

SummaryThe medical records of 39 horses treated for ulcerative keratomycosis over a 10 year period were reviewed. Records were evaluated to determine the medical and/or surgical treatment protocol, visual outcome, globe survival and whether the outcome was influenced by the fungal species isolated. Stromal abscesses and iris prolapses caused by fungi were not included. Twenty of the horses underwent medical treatment only, and 19 horses had combined medical and surgical treatment. Most horses had been treated with topical antibiotics (n = 32) and atropine sulphate (n = 23) prior to referral; topical antifungals had been employed less frequently (n = 14). Fungi were identified by cytology (n = 31), culture (n = 33) and/or surgical histopathology (n = 6).Aspergillus(n = 13) andFusarium(n = 10) were the most commonly isolated fungi. Miconazole (n = 35) was the most common topical antifungal medication utilised. Median duration of treatment was 48 days (range 31–192 days). Associated bacterial infection (n = 13) was frequently encountered. Visual outcome was favourable in 36/39 (92.3%) eyes. All eyes (20/20) retained vision following medical management only, and 16/19 (84%) retained vision following combined medical and surgical therapy. All medically treated horses (20/20), and 17/19 (89%) of those treated medically and surgically retained their globes. Overall ocular survival was favourable in 37/39 (94.9%) eyes.Aggressive therapy can result in successful results for equine ulcerative keratomycosis.
Measurement of cardiac function by transthoracic echocardiography: day to day variability and repeatability in normal Thoroughbred horses
Authors: YOUNG LESLEY E. , SCOTT G. R. 
Published: April 2010

SummaryIn order to assess the reliability and repeatability of transthoracic echocardiography for detecting serial changes in cardiac function in horses, day to day variability of a number of echocardiographic indices of ventricular function were studied. The variables investigated were, from 2‐dimensional (2‐D) and M‐mode echocardiography ‐ aortic diameter in systole (AoS), pulmonary artery diameter in systole (PaS), left ventricular internal diameter in systole (LLVIDS) and diastole (LLVIDd), and left ventricular fractional shortening (%FS) and estimated ejection fraction (EF). From pulsed Doppler echocardiography ‐ maximum velocity (Vmax) and acceleration (dv/dtmax) of aortic and pulmonary arterial blood flow, left and right ventricular velocity time integral (AoVTI and PAVTI) and estimated cardiac output (COLV, and CORV), left and right ventricular ejection time (LVET and RVET) and pre‐ejection period (LVPEP and RVPEP), and heart rate. Maximum velocity of early rapid right ventricular filling (ETV) and late right ventricular filling due to right atrial contraction (ATV) were measured. Maximum deceleration and time for deceleration of early rapid filling (dv/dtTVand dtTV) were also determined.Seven healthy mature Thoroughbred horses weighing 490–600 kg were studied. The horses' management regimes and environment were standardised and an echocardiographic examination was carried out on each horse at the same time every day for 6 consecutive days. Two statistical measures of repeatability were calculated for each variable: the intraclass correlation coefficient (rI) and the 95% confidence intervals for error free value of a single measurement.In general, the dimensions and indices of cardiac function derived from 2‐D and M‐mode echocardiography showed better repeatability for individual horses than did the indices derived from Doppler echocardiography. Overall the 95% confidence intervals for an error‐free value of all variables derived from Doppler echocardiography were wide. This must be appreciated when attributing serial measured changes of Doppler echocardiographic variables in an individual animal to effects of a treatment or disease.
Plasma 5‐hydroxytryptamine constricts equine digital blood vesselsin vitro: implications for pathogenesis of acute laminitis
Authors: BAILEY S. R. , ELLIOTT J. 
Published: April 2010

SummaryCumulative concentration response curves to 5‐hydroxytryptamine (5‐HT; 10‐10‐10‐4mol/l) were constructed using isolated rings of equine digital, facial, tail and coronary arteries (endothelium intact). 5‐HT was 17.7 and 41 times more potent as a vasoconstrictor of digital arteries than facial and tail arteries respectively. Removal of the endothelium increased the vasoconstrictor potency of 5‐HT in the facial artery by 3.7‐fold (P<0.05) but did not alter the sensitivity of digital arteries to 5‐HT. Coronary arteries failed to contract to 5‐HT. Coronary arteries pre‐contracted with U44069 showed concentration dependent relaxation to 5‐HT, a response which was partially dependent on the presence of the endothelium. No vasorelaxant effects were found in the digital or facial arteries. The concentration of 5‐HT in platelet poor and platelet rich equine plasma was found to be 6.70 ± 1.1 times 10‐8mol/l and 1.77 ± 0.36 times 10‐6mol/l (mean ± s.e.) respectively by high performance liquid chromatography (HPLC). Plasma which contained no detectable platelets had a 5‐HT concentration of 1.12 ± 0.48 times 10‐8mol/l. Isolated digital arteries constricted when exposed to dilutions of platelet poor and platelet depleted equine plasma. These plasma induced contractions were almost completely inhibited by 5‐HT receptor antagonists, ketanserin and methiothepin. The change in isometric tension in rings of equine digital arteryin vitrowas therefore used as a bioassay for plasma 5‐HT and the results obtained by this method showed an excellent correlation (r2= 97.2%, P<0.001) with the concentration estimated by HPLC. Circulating free concentrations of 5‐HT in normal horses may besufficient to constrict digital blood vessels partiallyin vivobut are well below the threshold for contraction of other peripheral blood vessels examined.
Scintigraphic and clinical findings in the Standardbred metatarsophalangeal joint: 114 cases (1993–1995)
Authors: ROSS M. W. 
Published: April 2010

SummaryTo correlate scintigraphic and clinical findings of the metatarsophalangeal joint (MTPJ) in Standardbreds, radiographic findings in horses with confirmed MTPJ lameness, and determine if stress reaction and more advanced bone remodelling occurred in the MTPJ, medical records of 114 Standardbreds admitted between September 1993 and April 1995 in which bone scintigraphy included standing lateral and plantar views of the metatarsophalangeal joint (MTPJ) were reviewed. Images obtained using a large field of view gamma camera were evaluated visually for location, definition and intensity of increased radioisotope uptake (IRU), which was graded as mild, moderate, or intense. Clinical history and lameness examination findings were recorded and, in horses with documented MTPJ lameness, radiographic examination included the 30° (down‐angled) dorsolateral 45° plantaromedial view thought to be useful in evaluation of the plantarolateral condyle of the third metatarsal bone (MtIII).The most common abnormality, IRU of the plantarolateral aspect of MtIII, was seen in 67 horses, and horses were further classified according to scintigraphic and clinical findings. In 43 horses in which lameness was not localised to the MTPJ, mild (32 horses), moderate (10 horses), and intense (one horse) IRU of MtIII was found. In 24 horses with lameness localised to the MTPJ, moderate (18 horses) and intense (6 horses) IRU was found. Of 18 horses with moderate IRU of MtIII, 9 had radiographic evidence of abnormal bony remodelling of MtIII, whereas 5 of 6 horses with intense IRU had radiographic changes. In 12 horses with MTPJ lameness and radiographic evidence of bony remodelling without fracture, radiographic changes consisted of plantarolateral subchondral radiolucency and sclerosis (7 horses), radiolucency and osteochondrosis (one horse), and plantar MtIII sclerosis without radiolucency (4 horses). In 2 horses with moderate IRU and MTPJ lameness, radiographic evidence of radiolucency and MtIII fracture was found. Of 19 starters with MTPJ lameness and IRU of MtIII, 18 horses raced after diagnosis, but only 13 remained at the same racing class or improved.The results of this study suggest the most common scintigraphic abnormality of the MTPJ, IRU of the plantarolateral aspect of MtIII, may precede other stress‐related changes, and in some horses is associated with a continuum of stress‐related subchondral bone remodelling which results in lameness and later radiographic changes. Since 24 of 35 horses with moderate or intense IRU of MtIII had MTPJ lameness, and 5 of 7 horses with intense IRU of MtIII had lameness and radiographic evidence of abnormal remodelling, it was concluded that horses with advanced, scintigraphic findings are more likely to have lameness and radiographic evidence of subchondral bone damage.
Behavioural changes in stabled horses given nontherapeutic levels of virginiamycin
Authors: JOHNSON K. G. , TYRRELL J. , ROWE J. B. , PETHICK D. W. 
Published: April 2010

SummaryAbnormal behaviour commonly develops in intensively managed horses. A possible cause is the change in diet occurring when the horse is stabled. An experiment was performed to examine this possibility by manipulating the diet with the feed supplement virginiamycin, as Founderguard. During 4 weeks, 18 horses were fed diets ranging from hay alone to concentrate plus hay in the ratio of 3:1. The rations of half the horses given concentrate were supplemented with Founderguard. Horses eating high concentrate rations displayed abnormal oral behaviours at a higher frequency than those eating only hay. The incidence of these behaviours was reduced when diets were supplemented with Founderguard. The drop in faecal pH of animals on concentrate diets was also reduced by Founderguard. Animals on concentrate diets had an average of 21 kg less gut fill post mortem. Dietary supplementation with virginiamycin as Founderguard apparently lessens some behavioural problems associated with management of stabled horses and the intake of grain. It may allow concentrate to be fed at higher levels than customary without adverse behavioural side effects. The suggested mechanism for the improved behaviour due to Founderguard supplementation is reduced fermentative acidosis in the hindgut.