bluuebunny/crossref_metadata_2025_split huggingface dataset:
An immunoperoxidase method applied to the diagnosis of equine herpesvirus abortion, using conventional and rapid microwave techniques
Authors: WHITWELL KATHERINE E. , GOWER SUSAN M. , SMITH K. C. 
Published: April 2010

SummaryAn indirect immunoperoxidase (IMP) technique was applied to cryostat and paraffin sections of liver from ten aborted equine foetuses. Equid herpesvirus type 1 (EHV‐1) had been isolated from seven of them and EHV‐4 from one: the remaining two were virologically negative and were not used as controls. In the eight virus‐infected cases the immunostaining revealed foci of cells exhibiting a distinct brown cytoplasmic and inclusion body pigmentation. No specific signal was present in the non‐infected controls. The method also was adapted for incubation in a microwave oven, which allowed the total length of the procedure to be reduced to a minimum of 35 mins for cryostat sections, without significant loss of signal.
Pathological findings in horses dying during an outbreak of the paralytic form of Equid herpesvirus type 1 (EHV‐1) infection
Authors: WHITWELL KATHERINE E. , BLUNDEN A. S. 
Published: April 2010

SummaryIn 1988 an outbreak of the paralytic form of Equid herpesvirus type 1 (EHV‐1) infection occurred on a stud farm and several animals died. This provided an opportunity to perform detailed pathological investigations to gain insights into the pathogenesis of this spontaneous disease. Two paretic mares, three foals, an aborted foetus and its non‐paretic dam were examined. The endotheliotropism of the virus was clearly demonstrated by the use of an indirect immunoperoxidase (IP) stain. At autopsy, evidence of viral infection was widespread in the foetus and foals, but limited or absent in the mares, probably reflecting differences in their immune status. Vascular lesions were present in the central nervous system (CNS) of the foals as well as the adults; they resulted in minimal neural lesions in the foals. Severe changes in the upper and lower respiratory tracts were a particular feature in the foals, two of which exhibited extensive vasculitis and thrombosis in the lungs. The IP technique was of great value in locating antigen‐containing cells in the CNS of one mare when virus isolation was negative. It also revealed the presence of virus in less well documented sites such as the pancreas, gut, thyroid, uveal tract and the skin of the nares.
Cardiovascular effects and fatalities associated with intravenous administration of doxycycline to horses and ponies
Authors: RIOND J.‐L , RIVIERE J. E. , DUCKETT W. M. , ATKINS C. E. , JERNIGAN A. D. , RIKIHISA Y. , SPURLOCK S. L. 
Published: April 2010

SummaryIntravenous use of doxycycline in horses is associated with deleterious side effects on the cardiovascular system which may result in fatalities. At dosages and infusion rates used in these studies, supraventricular tachycardia, systemic arterial hypertension, clinical signs of discomfort, collapse and death were observed. Results of the present study suggest that the intravenous use of doxycycline should be avoided in horses.
Effects of induced alkalosis on performance in Thoroughbreds during a 1,600‐m race
Authors: HARKINS J. D. , KAMERLING S. G. 
Published: April 2010

SummaryThere is considerable debate regarding the ergogenic effects of sodium bicarbonate (NaHCO3) on racing performance in horses. Anecdotal evidence suggests that NaHCO3 improves performance by increasing the buffering capacity of the blood and delaying the onset of hydrogen ion‐induced fatigue. In a cross‐over study, 16 Thoroughbred racehorses were given an aqueous solution of NaHCO3 (0.4 g/kg in 1 litre H2O) or a control treatment (1 litre H2O) before a 1600‐m race. Treatments were administered 3 h before the race, which was the time to peak buffering capacity (2.5‐3.0 h) determined in a separate study. Before the race, there was a significant increase in venous HCO3− and pH in the NaHCO3‐treated horses. After the race, there was a significant increase in venous blood pH and lactate in the NaHCO3‐treated horses. Collectively, the data suggest an improved buffering capacity of the blood after NaHCO3 treatment. However, there was no change in race times or venous partial pressure of carbon dioxide. Therefore, the administration of NaHCO3 provided no ergogenic benefit to horses competing in a 1,600‐m race.
Inhibition of interleukin‐1 activity by equine synovial fluid
Authors: MAY S. A. , HOOKE REBECCA E. , LEES P. 
Published: April 2010

SummaryThe presence, in equine synovial fluid, of inhibitors of interleukin‐1 (IL‐1) activity has been investigated by means of an assay involving IL‐1‐mediated production of PGE2 by synovial cells. Inhibitors of IL‐1α and IL‐1β were identified in normal synovial fluid and synovial fluid from two horses with early joint disease. Inhibitors of IL‐1α were also present in synovial fluid from two horses with long‐standing joint disease. However, IL‐1β inhibitory activity was not present in fluid from the horses with more chronic joint disease. The effect appeared to be specific for IL‐1, and not a direct action on PGE2 production, as synovial fluid had no effect on lipopolysaccharide‐mediated PGE2 production. It is suggested that the inhibitory activity may be involved physiologically in the control of IL‐1 activity in the joint, and the loss of IL‐1 inhibition may be at least as important biologically as increased production of IL‐1.
Aerosol pirbuterol: bronchodilator activity and side effects in ponies with recurrent airway obstruction (heaves)
Authors: DERKSEN F. J. , ROBINSON N. E. , BERNEY C. E. 
Published: April 2010

SummaryThe dose of aerosol pirbuterol that could be administered safely to ponies (weight approximately 200 kg) was determined by observation for sweating, trembling and excitement and measurement of heart and respiratory rates during cumulative administration of the drug. Sweating, trembling and excitement were first observed following a dose of 2,400 μg and became more severe at 3,200 μg. These effects were accompanied by an increase in heart rate but not a change in respiratory rate. When 3200 μg was administered without prior administration of lower doses, side effects were trivial. This dose was therefore tested for its bronchodilator activity. Pulmonary function was evaluated in ponies that developed airway obstruction (‘heaves’) when housed in a barn and fed hay. Measurements were made when ponies were in clinical remission (Period A) and during an acute attack of airway obstruction (Period B). At Period A, pirbuterol had no effect on pulmonary function. Barn housing increased pulmonary resistance and decreased dynamic compliance. At Measurement Period B, pirbuterol administration significantly reduced pulmonary resistance and increased dynamic compliance and minute ventilation. These changes were significant 5 min after drug administration and lasted for the 30 min duration of the study. Vehicle administration had no effect on pulmonary function. It was concluded that aerosol pirbuterol has few undesirable side effects and is an effective bronchodilator in ponies with recurrent airway obstruction.
Spontaneous echocardiographic contrast in the Thoroughbred: high prevalence in racehorses and a characteristic abnormality in bleeders
Authors: MAHONY CHERYL , RANTANEN N. W. , DeMICHAEL J. A. , KINCAID B. 
Published: April 2010

SummarySpontaneous echocardiographic contrast is the term used by ultrasonographers to describe particulate material visible in intracardiac blood by ultrasound. The purpose of the present study was to determine the prevalence of spontaneous contrast in a farm population of Thoroughbreds and in the farm's racehorses. The results showed that spontaneous echocardiographic contrast is common in Thoroughbreds, and that the prevalence of contrast is affected by age, male gender, racing and pregnancy. The amount of right‐sided cardiac contrast was quantitated by videodensitometry and was increased in horses with a history of exercise‐induced pulmonary haemorrhage, in comparison with racehorses without a history of bleeding. Since circulating platelet aggregates are known to produce pulmonary haemorrhage in experimental animals and their presence has been associated with echocardiographic contrast, additional studies evaluating platelet aggregates as the aetiologic agent for exercise‐induced pulmonary haemorrhage are warranted.
Hoof and distal limb surface temperature in the normal pony under constant and changing ambient temperatures
Authors: MOGG KARIN C. , POLLITT C. C. 
Published: April 2010

SummaryForelimb surface temperatures were continuously monitored in four clinically normal ponies exposed to: (i) constant ambient temperature; (ii) a biphasic change in ambient temperature; and (iii) an incremental increase in ambient temperature. Limb surface temperatures were recorded at the hoof, metacarpus and forearm, and rectal temperature was also measured. Under constant ambient temperature, limb surface temperatures remained relatively constant. A pyrexic episode occurred in one pony under constant ambient temperature conditions and was characterised by an onset phase in which rectal temperature gradually increased while limb surface temperatures concurrently decreased; a plateau phase in which rectal temperature was elevated but essentially constant although limb surface temperatures rose dramatically; and a febrilytic phase in which limb surface temperatures remained elevated while rectal temperature gradually decreased. A biphasic change in ambient temperature produced corresponding changes in limb surface temperature, but limb surface temperatures were less stable at the lower ambient temperatures. Surface temperature responses to incremental increases in ambient temperature were dependent on the baseline ambient temperature (before increase), and dramatic, spontaneous increases in limb surface temperatures were observed. Rectal temperatures in the normal animals remained relatively constant under all three ambient temperature regimens.It was concluded that clinical interpretation of limb surface temperatures in ponies required an awareness of ambient temperature conditions. For evaluation of vasodilator agents, constant ambient temperatures of at least less than 18°C are suggested, and constant ambient temperatures exceeding 20°C are recommended for the evaluation of vasoconstrictor agents.
Factors associated with the risk of developing sarcoid tumours in horses
Authors: MOHAMMED H. O. , REBHUN W. C. , ANTCZAK D. F. 
Published: April 2010

SummaryA retrospective case‐control study was conducted to identify risk factors in horses associated with the development of the common skin tumours known as sarcoids. The study involved 503 sarcoid cases diagnosed (January 1980‐December 1989) at New York State College of Veterinary Medicine and a similar number of controls (non‐sarcoid cases). Data on age, breed and sex of cases and controls were obtained from computerised records. Multiple logistic regression analysis was used to identify risk factors. Separate data were obtained for the same 10‐year period from the Veterinary Medical Data Program to determine the proportional morbidity rate at different veterinary colleges in North America. Appaloosa, Arabian and Quarter horses were at a higher risk of developing sarcoid tumours than were Thoroughbred horses. Standardbred horses had a lower risk of developing sarcoids. Geldings were at a higher risk of developing sarcoids in comparison with stallions. There was no significant difference in the risk of developing sarcoids between stallions and mares. The risk of developing sarcoid increased with age up to 15 years and then declined. The proportional morbidity rate of sarcoids among the veterinary colleges ranged between 0 and 14 per 1,000 cases, with an average of 6 per 1,000.
Improved insulin sensitivity in hyperinsulinaemic ponies through physical conditioning and controlled feed intake
Authors: FREESTONE J. F. , BEADLE R. , SHOEMAKER K. , BESSIN R. T. , WOLFSHEIMER K. J. , CHURCH C. 
Published: April 2010

SummaryTen hyperinsulinaemic ponies divided into conditioned (N = 5) and rested (N = 5) groups were evaluated for their insulin and glucose response following oral glucose administration at Weeks 0, 2, 4, and 6. All ponies received a controlled intake of a pelleted ration during the study.In both groups body weight had decreased from baseline by Week 4 and remained low. After 2 weeks of exercise, ponies in the conditioned group had significantly decreased insulin and glucose indices, including peak insulin response, area under the insulin curve from 0 to 210 min (TIS), and the TIS value: area under the glucose curve from 0 to 210 min. By Week 4 of conditioning, although the insulin and glucose indices continued to decrease in the exercised ponies, there was no significant difference between the groups. Over the first 6 weeks of the study all ponies improved their insulin sensitivity accompanied by a loss of body weight.The conditioned ponies were further evaluated during deconditioning at Weeks 8, 10 and 12. The improved insulin sensitivity was maintained during deconditioning.
Inflammatory effects of platelet activating factor (PAF) in equine skin
Authors: FOSTER A. P. , CUNNINGHAM F. M. , LEES P. 
Published: April 2010

SummaryIntradermal administration of PAF (0.001 −1 μg/site), but not lyso‐PAF (10 μg/site), in the horse caused an increase in cutaneous vascular permeability which was maximal by 32 min. Responses to PAF and histamine were reduced by coadministration of the histamine 1 receptor antagonist chlorpheniramine, although only the inhibition of histamine‐induced responses was dose‐related and statistically significant. The cyclo‐oxygenase inhibitor indomethacin was without effect on PAF‐induced increases in vascular permeability. These findings suggest that the actions of PAF on equine skin microvasculature may be partly due to histamine release but not to prostanoid formation. Coadministration of prostaglandin (PG) E2 enhanced the oedematous responses to both PAF and histamine, although PGE2 failed to exert direct permeability‐increasing activity. In addition, and in contrast to PAF and histamine, PGE2 increased cutaneous blood flow and skin surface temperature. PAF, but not lyso‐PAF, also caused neutrophil infiltration into the skin which was maximal at 2 h. No significant effects on eosinophil or mononuclear cell numbers were apparent up to 24 h after injection of PAF. These results are consistent with the concept that PAF may be a mediator of inflammatory disorders of the skin in the horse.
Microwave thermography: a non‐invasive technique for investigation of injury of the superficial digital flexor tendon in the horse
Authors: MARR CELIA M. 
Published: April 2010

SummaryMicrowave thermographs were recorded from 77 normal horses. In 51% the lowest temperature was recorded in the mid‐metacarpal region, and in 41% it was in the distal metacarpal region. The mean temperature of the normal limbs rangesd from 25.04 to .37.4°C. Maximum temperature differences between symmetrical points in both forelimbs ranged from 0 to 5.33°C and differences in mean limb temperatures between both forelimbs ranged from 0 to 2.91°C.In 48 horses with acute (<4 weeks' duration) injury of the superficial digital flexor tendon (SDFT) (36 unilateral, 12 bilateral) and 12 horses with acute injury of the soft tissues of the palmar metacarpal region other than the SDFT (all unilateral) 66% of forelimbs had acute SDFT injury, and 50% of those with other soft tissue injuries, had elevations of the temperature in the mid‐ or distal metacarpal region. Abnormal values for mean limb temperature, difference in mean limb temperature and maximum temperature difference between locations in opposite forelimbs were detected in 75% of the horses with SDFT injury and in only 16% of the horses with other soft tissue injury. The sensitivity of microwave thermography for the detection of SDFT injury was 81% and the specificity 74%.When 30 horses in National Hunt training were examined weekly for 5 weeks, 2 horses sustained SDFT injury during that period. The microwave thermographs recorded from these 2 horses, at 1 and 2 weeks before the onset of clinical signs, were abnormal. However, 16 horses which did not develop tendon injury also displayed thermographic abnormalities.
Videoendoscopic evaluation of the mare's uterus: I. Findings in normal fertile mares
Authors: BRACHER VERENA , ALLEN W. R. 
Published: April 2010

SummaryThe new generation of videoendoscopes uses an electronic, instead of an optical, system for image transmission. Advantages over conventional fibre‐optic endoscopes include increased image quality, handling robustness and direct display of the image on a TV monitor for multiple simultaneous viewing. In the present study, hysteroscopy was performed on 14 normal fertile Welsh Pony and Thoroughbred mares at various times during the annual and ovarian breeding cycles. Oestrus was characterised by an oedematous, relaxed cervix lying on the floor of the vagina, diffuse oedema of the endometrium and the occasional accumulation of small amounts of clear secretions in the uterine lumen. In dioestrus, the cervix appeared tight and pale and was located in the centre of the vaginal fornix. The endometrium appeared thinner due to the reduction in interstitial fluid, which allowed the underlying blood vessels to become visible, but it still had a glistening surface as a result of endometrial gland secretions. The appearance of the uterotubal papillae reflected the changes in the cervix, being relaxed, pinkish and oedematous during oestrus but remaining pale, tight and erect in dioestrus (between Days 7 and 12 after ovulation).A flexible polythene cannula was passed into the uterine lumen through the working channel of the endoscope for directed collection of uterine fluid for cytological and bacteriological examinations. Site‐directed biopsies of the endometrium were taken, with flexible forceps inserted through the working channel of the endoscope, or with rigid forceps passed through the cervix alongside the endoscope. Both methods enabled accurate visual selection of the sampling area but the rigid forceps were preferred due to the larger size of the piece of endometrium recovered.
Radiographic anatomy of soft tissue attachments in the equine metacarpophalangeal and proximal phalangeal region
Authors: WEAVER J. C. B. , STOVER SUSAN M. , O'BRIEN T. R. 
Published: April 2010

SummaryThe sites of bony attachment of the tendons, ligaments, and fibrous portion of the joint capsules of the equine metacarpophalangeal (fetlock) joint region were determined by gross dissection. These sites were transposed to standard radiographic views of the fetlock joint to yield illustrations that can be used as an aid in the diagnosis of soft tissue pathology from radiographs. Evidence of direct attachment of the common digital extensor tendon to the proximal phalanx was not found. Branches of the superficial digital flexor tendon were found to insert only on the middle phalanx. The recently described sites of insertion of the branches of the superficial digital flexor tendon to the proximal phalanx were found to be sites for attachment of the deep abaxial palmar ligaments of the proximal interphalangeal joint.
Plasma lipids, lipoproteins and post‐heparin lipases in ponies with hyperlipaemia
Authors: WATSON T. D. G. , BURNS L. , LOVE S. , PACKARD C. J. , SHEPHERD J. 
Published: April 2010

SummaryThe metabolic origins of equine hyperlipaemia were investigated by analysing the concentration and composition of plasma lipoproteins in 18 ponies with the condition. The mean concentrations of cholesterol, triglyceride and very low density lipoproteins (VLDL) were increased by 4‐, 52‐ and 19‐fold, respectively, compared with a control group of 18 healthy ponies. These increases were due to the appearance of a buoyant VLDL fraction (VLDL1) not present in healthy ponies. The mean diameter of VLDL1particles was 44% greater than control VLDL, and the particles were enriched in triglyceride and free cholesterol and depleted of cholesteryl esters, phospholipid and protein. The apolipoprotein (apo) B‐100 content of VLDL1was reduced and the ratio of apoB‐100 to apoB‐48 particles was 1:1, compared with 2:1 in control VLDL. The VLDL1was also enriched in apoE, but had normal complements of apoC‐II and apoC‐III. The conventional VLDL (called VLDL2), LDL and HDL fractions were moderately enriched with triglyceride, and HDL contained increased amounts of apoE, apoC‐II and apoC‐III. The activities of lipoprotein lipase and hepatic lipase, the enzymes responsible for the catabolism of VLDL and their remnants, were increased by 2‐ and 3‐fold, respectively, in response to the increased concentrations of their substrates. The composition of VLDL1suggested that the liver was maximising the secretion of triglyceride by producing larger number of VLDL particles that accommodated a greater mass of triglyceride by having apoB‐48 rather than apoB‐100 as their structural protein. Plasma free fatty acid (FFA) concentrations were elevated in 17 of the 18 ponies, suggesting that increased FFA flux might be the stimulus for hepatic triglyceride synthesis and VLDL secretion. We conclude that overproduction, rather than defective catabolism, of VLDL was the cause of the hyperlipidaemia and that lipid lowering agents which reduce VLDL synthesis, by decreasing adipose lipolysis and FFA flux, are candidates for the management of hyperlipaemia.
Increase in plasma progestagen concentrations in the mare after foetal injection with CRH, ACTH or betamethasone in late gestation
Authors: ROSSDALE P. D. , McGLADDERY A. J. , OUSEY JENNIFER C. , HOLDSTOCK NICHOLA , GRAINGER L. , HOUGHTON E. 
Published: April 2010

SummaryMaternal plasma progestagen concentrations increase about 20 days before parturition. The major contributors to the increase are reduced metabolites (ie 5α‐pregnanes). Precocious increases (ie < 310 days of gestation) in these metabolites may occur in abnormal pregnancies. The effects of CRH, ACTH or betamethasone administered to the foetus at gestational ages ranging from about 250 to 320 days were examined. Sixteen healthy pony mares were used for foetal injection employing aseptic techniques. Water or normal saline were used as controls. Maternal plasma progestagen concentrations were measured using a commercial radioimmunoassay (RIA) progesterone kit and results were confirmed using gas chromatography‐mass spectrometry (GC‐MS). Results demonstrated clearly that an increase in maternal plasma progestagen concentrations occurred after injection of ACTH, CRH or betamethasone to the foetus, irrespective of gestational age. A comparable increase was not observed in the control animals. Of the 16 mares in which the foetus was injected, 13 produced viable foals at gestational ages ranging from 307 to 339 days whereas 3 mares delivered non‐viable foals at 284 to 306 days gestation. The results support the hypothesis that the pre‐parturient rise in progestagens occurring in the mare is the result of foetal adrenocortical activity.