[Glyphosate detection in the duodenal fluid of horses with gastric ulcer syndrome]. / Glyphosatnachweis in der Duoden­alflüssigkeit bei Pferden mit Magenulzerasyndrom.

INTRODUCTION: The hay producing plants, concentrate, straw and meadows could be contaminated by the aerosols of glyphosate based herbicide during spraying process of crops and pre-harvest desiccation treatment of cereals. The aim of this study is to investigate the concentration of glyphosate in the duodenal fluid of horses with gastric ulcer syndrome. The stomach and duodenum of referred untreated horse patients (n=92) with colic, weight loss, diarrhoea, anemia or performance intolerance were endoscopically examined right after the admission. Duodenal fluid (40 ml) was collected from the duodenal region where the papilla duodeni major is located. Hematology and clinical chemistry data were examined. The concentration of glyphosate in serum and duodenal fluid samples were analysed using a competitive ELISA and control analysis had also been done with HPLC. Statistical differences between groups were determined by the non-parametric Mann-Whitney-test using a significant level of p≤0,05. Glyphosate was detected in all duodenal fluid (median 12,2 ng/ml; 1st quartile 4,0 ng/ml; 3rd quartile 19,3 ng/ml; min 0,6 ng/ml; max. 192,9 ng/ml) and blood samples (1,79 ng/ml; 1,0 ng/ml; 2,8 ng/ml; 0,2 ng/ml; 3,7 ng/ml) of all horses. Glyphosate concentrations of duodenal fluid samples are significantly higher than in blood samples (Mann Whitney U-test, p≤0,05). The concentration of glyphosate in the duodenal fluid was significantly higher in horses with squamous gastric disease (grade 4/4; n=11/92) compared to horses with normal squamous mucosa (grade 0/4, n=10/92) (median: 19,8 ng/ml versus 8,4 ng/ml). Horses with glandular gastric disease and a grade 4/4 (n=9/92) had higher concentrations of glyphosate in the duodenal fluid than horses with normal glandular mucosa (grade 0/4; n=9/92) (median: 19,2 versus 11,1). The Gamma-Glutamyltransferase (GGT) enzyme activity is significantly higher in the group of horses with lower concentration of glyphosate in the duodenal fluid (≤12,2 ng/ml) compared with the group with higher concentration of glyphosate (>12,2 ng/ml) (median 279,5 versus 101,9 U/L). During autumn the horses had higher concentrations of glyphosate in duodenal fluid (n=18; median 14,3) compared with lower concentrations in spring time (n=34; median 8,1 ng/ml). Horses kept around big cities had significantly higher concentrations of glyphosate in the duodenal fluid in comparison to horses living in the countryside (medians 17,8 ng/ml versus 7,5 ng/ml).

INTRODUCTION: L'herbicide glyphosate, y compris le surfactant, est utilisé contre les mauvaises herbes dans l'agriculture, les maisons, les jardins et les parcs, les bords de route ainsi que sur les remblais des voies ferrées. La pulvérisation de cet herbicide engendre sa dispersion et donc la contamination des champs, des prairies et des pâturages et, par conséquent, des céréales, du foin, de la paille et du haylage, entraînant ainsi une ingestion orale chez les chevaux. Afin de déterminer l'étendue de l'utilisation du glyphosate dans la région du centre de l'Allemagne et d'identifier un éventuel facteur de risque pour le déclenchement du syndrome de l'ulcère gastrique, le liquide duodénal a été testé par rapport au glyphosate chez des patients équins. Les chevaux référés et non traités (n=92) présentant des antécédents de colique, d>amaigrissement, de diarrhée, d>anémie ou de baisse de performance ont été soumis à une gastroduodénoscopie le jour de leur admission. La graduation des lésions des muqueuses de l'estomac et du duodénum a été effectuée, 40 ml de liquide duodénal ont été aspirés et 20 ml de sang ont été prélevés en parallèle. Des analyses hématologiques et chimiques du sang ainsi que des analyses chimiques du liquide duodénal ont été effectuées. Le glyphosate a été détecté dans le sérum et le liquide duodénal à l'aide d'un test ELISA direct et compétitif et, parallèlement, d'une chromatographie liquide haute performance. Le glyphosate a été détecté dans le liquide duodénal (médiane 12,2 ng/ml, 1er quartile 4,0 ng/ml ; 3e quartile 19,3 ng/ml ; min 0,6 ng/ml ; max 192,9 ng/ml) et dans le sang (1,79 ng/ml ; 1,0 ng/ml ; 2,8 ng/ml ; 0,2 ng/ml ; 3,7 ng/ml) de tous les chevaux étudiés. La concentration de glyphosate dans le liquide duodénal est significativement plus élevée que dans le sang (test U de Mann Whitney, p≤0,05). Les chevaux présentant des lésions cutanées (n=11/92) ou glandulaires (n=9/92) de la muqueuse gastrique de grade 4/4 présentaient des concentrations de glyphosate dans le liquide duodénal significativement plus élevées ou plus élevées que ceux de grade 0/4 (n=10 et 9 respectivement) (médiane : 19,8 ng/ml versus 8,4 ng/ml ou 19,2 ng/ml versus 11,1 ng/ml). L'activité de la gamma-glutamyltransférase (GGT) dans le liquide duodénal était significativement plus élevée (médiane de 279,5 U/L) dans le groupe de chevaux présentant une faible concentration de glyphosate (≤12,2 ng/ml) que dans le groupe de chevaux présentant une concentration plus élevée de glyphosate (>12,2 ng/ml) (médiane de 101,9 U/L). La concentration de glyphosate était plus élevée pendant l'automne (n=18 ; médiane 14,3 ng/ml) et plus faible au printemps (n=34 ; médiane 8,1 ng/ml). Des concentrations significativement plus élevées de glyphosate dans le liquide duodénal ont été mesurées chez les chevaux détenus autour des grandes villes (17,8 ng/ml) par rapport aux chevaux vivant dans les zones rurales (7,5 ng/ml).

[Reference ranges of insulin, insulin like growth factor-1 and adrenocorticotropic hormone in ponies]. / Referenzbereiche von Insulin, insulinähnlichem Wachstumsfaktor 1 (IGF-1) und adrenokortikotropem Hormon bei Ponys.

OBJECTIVES: The aim of this study was to validate a chemiluminescence immunometric assay using the IMMULITE 2000® for the determination of adrenocorticotropic hormone (ACTH), insulin and insulin-like growth factor-1 (IGF-1) from which reference ranges were calculated for ponies. MATERIAL AND METHODS: Blood samples of 130 ponies aged 3-32 years were collected in the afternoon. The reference ranges were calculated according to the Guideline EP28-A3C of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) from 2010. RESULTS: The determined intraday precision for insulin was 3.28%, for ACTH 3.35% and for IGF-1 1.84%. The interday precision (insulin: 3.45%; IGF-1: 2.89%; ACTH: 9.77%) was determined on three consecutive days, where the samples were stored at 4   °C. There was no significant loss of insulin activity nor of ACTH or IGF-1 concentration during this time. The reference ranges of insulin and IGF-1 (2.0-21.2 mU/l and 50.2-357.2 mU/l, respectively) were age independent, whereas for ACTH, an age-dependent reference range was established. Ponies aged 3-12 years had a significantly lower reference range (4.2-19.8 pg/ml) than ponies aged 13-32 years (5.0-22.6 pg/ml). CONCLUSION: The method used is suitable for the determination of ACTH, IGF-1 and insulin in serum of ponies, but the lowest detection limit for insulin is 2.0 mU/l. CLINICAL RELEVANCE: The calculated reference ranges of insulin and ACTH are helpful for the diagnosis and clinical monitoring of equine metabolic syndrome and pituitary pars intermedia dysfunction (PPID).

Hypoglycin A Content in Blood and Urine Discriminates Horses with Atypical Myopathy from Clinically Normal Horses Grazing on the Same Pasture.

Hypoglycin A (HGA) in seeds of Acer spp. is suspected to cause seasonal pasture myopathy in North America and equine atypical myopathy (AM) in Europe, fatal diseases in horses on pasture. In previous studies, this suspicion was substantiated by the correlation of seed HGA content with the concentrations of toxic metabolites in urine and serum (MCPA-conjugates) of affected horses. However, seed sampling was conducted after rather than during an outbreak of the disease. The aim of this study was to further confirm the causality between HGA occurrence and disease outbreak by seed sampling during an outbreak and the determination of i) HGA in seeds and of ii) HGA and MCPA-conjugates in urine and serum of diseased horses. Furthermore, cograzing healthy horses, which were present on AM affected pastures, were also investigated. AM-pastures in Germany were visited to identify seeds of Acer pseudoplatanus and serum (n = 8) as well as urine (n = 6) from a total of 16 diseased horses were analyzed for amino acid composition by LC-ESI-MS/MS, with a special focus on the content of HGA. Additionally, the content of its toxic metabolite was measured in its conjugated form in body fluids (UPLC-MS/MS). The seeds contained 1.7-319.8 µg HGA/g seed. The content of HGA in serum of affected horses ranged from 387.8-8493.8 µg/L (controls < 10 µg/L), and in urine from 143.8-926.4 µg/L (controls < 10 µg/L), respectively. Healthy cograzing horses on AM-pastures showed higher serum (108.8 ± 83.76 µg/L) and urine concentrations (26.9 ± 7.39 µg/L) compared to control horses, but lower concentrations compared to diseased horses. The range of MCPA-carnitine and creatinine concentrations found in diseased horses in serum and urine were 0.17-0.65 mmol/L (controls < 0.01), and 0.34-2.05 µmol/mmoL (controls < 0.001), respectively. MCPA-glycine levels in urine of cograzing horses were higher compared to controls. Thus, the causal link between HGA intoxication and disease outbreak could be further substantiated, and the early detection of HGA in cograzing horses, which are clinically normal, might be a promising step in prophylaxis.

Histological study of the external, middle and inner ear of horses.

Clinical, anatomical and histological aspects of the equine acoustic organ have been poorly investigated and illustrated in literature so far. It is understood that an intact acoustic organ and hearing function are of vital importance for the well-being of flight animals like horses. The knowledge of the acoustic organ is usually transferred analogously from other mammals to horses. The purpose of this study was to provide a detailed and complete histological description of the healthy equine auditory organ, and to determine its congruity to other mammalians. Anatomical dissections and histological preparations were carried out on ten cadaver heads. Specimens of various parts of the equine acoustic organ were taken and evaluated histologically. The histological composition of external, middle and inner ear structures are predominantly congruent to those of other mammals, especially to human beings. Unique inwardly directed rete pegs within the osseous ear canal and the prominent tensor tympani muscle are described for the first time. Results obtained in this study can be employed as references for further research on the equine acoustic organ and improve the understanding of the clinical development of hearing loss, otitis externa/media/interna or tympanosclerosis.

[Diagnostic assessment of peritoneal fluid cytology in horses with abdominal neoplasia]. / Diagnostische Aussagekraft der Zytologie von Bauchpunktaten bei abdominalen Tumoren des Pferdes.

OBJECTIVE: To evaluate the diagnostic value of peritoneal fluid (PF) cytology for clinical diagnosis of abdominal neoplasia in horses. MATERIAL AND METHODS: Ten horses with histopathologically confirmed abdominal neoplasia, in which a PF analysis was performed, were included in this retrospective study. PF was analyzed for total protein concentration and a nucleated cell count was performed. Using cytological criteria of malignancy, the PF samples were evaluated regarding their probability of malignancy. RESULTS: Cytologic classification of cells according to criteria of malignancy allowed a positive cytologic diagnosis of neoplasia in 5 out of 10 peritoneal fluid samples. Malignant lymphoma was the most commonly diagnosed neoplasia (3/10) and could be identified by cytology in 2/3 cases. In 1/2 horses with plasma cell myeloma neoplastic cells were similarly found. Malignant melanoma (2/10) was diagnosed using cytology in one case (presence of melanin-containing cells). Cytological diagnosis of malignant neoplasia was established in the only horse with gastric squamous cell carcinoma, but the morphology of the identified tumour cells did not allow a specific diagnosis. Thus, a definitive diagnosis was achieved in 4/5 horses with proven abdominal neoplasia. The horses with adenocarcinoma (1/10) and haemangiosarcoma (1/10) had no evidence of neoplasia based on cytological findings. No relationship between total protein concentration or the nucleated cell count with the histolopathological diagnosis of abdominal neoplasia was found. Abnormal mitotic figures were considered of greater diagnostic value than the overall mitotic rate. CONCLUSION: The implementation of nuclear criteria of malignancy in the cytologic evaluation of PF samples allows the identification of neoplastic cells to an acceptable degree. For this purpose, the knowledge of the highly variable morphological features of mesothelial cells is essential. The absence of malignant cells does not rule out abdominal neoplasia. CLINICAL RELEVANCE: PF cytology should be considered as a valuable, minimally invasive, simple, and rapid diagnostic technique in horses with suspected abdominal neoplasia.

Anatomy and anaesthesia of the equine external ear canal.

Anaesthesia of the external ear canal (external acoustic meatus) is usually performed by blocking both the great and internal auricular nerves by regional infiltration. However, exact landmarks for blocking the internal auricular nerve to accomplish effective anaesthesia have not been described yet. In this study, detailed anatomical dissection of the equine external ear canal and its nerve supply was carried out on fifteen cadaver heads. Tissue samples of the dissected nerves were taken from two cadaver heads processed and were evaluated microscopically. Prior to the dissection, the region of interest was evaluated ultrasonographically, and injection of a local anaesthetic was simulated with an injection of methylene blue on ten cadaver heads. The tympanic membranes of three cadaver heads were obtained by microdissection and processed for microscopic evaluation. The entrance point of the internal auricular nerve, which is a branch of the facial nerve, into the ear canal is formed by the styloid process of the auricular cartilage. Using ultrasound, the styloid process presented as a thin hyperechoic line 2.17-2.97 cm deep, based on the skin surface. Landmarks for performing a complete and reliable anaesthesia of the external ear canal were established, and the simulated anaesthesia with methylene blue injection was evaluated as successful in all ten cases. Additionally, the histological composition of the equine tympanic membrane is described and illustrated.

Effects of dermal dexamethasone application on ACTH and both basal and ACTH-stimulated cortisol concentration in normal horses.

There are no data available regarding the systemic (adverse) effects which might be induced by topical/dermal glucocorticoids (GCs) application in the horse. Besides their widespread use for the treatment of a variety of peripheral inflammatory disorders such as atopic dermatitis, eczemas or arthritis in the horse, their surreptitious application has become a concern in doping cases in competition/performance horses. Assessing both basal and ACTH-stimulated plasma cortisol as well as basal ACTH concentrations following application of dexamethsone-containing dermal ointment is necessary to determine influences on hypothalamus-pituitary-adrenal (HPA) axis. Ten clinically healthy adult standardbred horses (6 mares, 4 geldings) were rubbed twice daily each with 50 g dexamethasone-containing ointment on a defined skin area (30 x 50 cm) for 10 days. RIA and chemiluminescent enzyme immuno-metric assay were used to determine resting and ACTH-stimulated plasma cortisol and basal ACTH concentrations, respectively. HPA feedback sensitivity and adrenal function were measured by a standard ACTH stimulation test. Dermal dexamethasone suppressed significantly the resting plasma cortisol level (to 75-98%) below baseline (P < 0.001) within the first 2 days and decreased further until day 10. ACTH stimulation test showed a markedly reduced rise in plasma cortisol concentrations (P < 0.001 vs. baseline). Plasma ACTH level decreased also during topical dexamethasone application. The number of total lymphocytes and eosinophil granulocytes was reduced, whereas the number of neutrophils increased. No significant change of serum biochemical parameters was noted. Dermal dexamethasone application has the potential to cause an almost complete and transient HPA axis suppression and altered leukocyte distribution in normal horses. The effects on HPA axis function should be considered in relation to the inability of animals to resist stress situations. The data further implicate that percutaneously absorbed dexamethasone (GCs) may cause systemic effects relevant to 'doping'.

Effect of hydroxyethyl starch solution in normal horses and horses with colic or acute colitis.

Hydroxyethyl starch (HES) solution is an effective colloidal infusion solution in humans for treatment of hypovolaemic shock, but it has not been compared with fluids currently available for use in horses. On the basis of plasma-expanding effect of HES in normal horses, a 10% medium-molecular 200/0.5 solution of HES was subsequently tested in hypovolaemic horses. Six normal horses were given five protocols of a single infusion of HES at varying dosage rates (5, 10, 15 ml HES/kg), as well as isotonic saline (15 ml/kg) and hypertonic saline (4 ml/kg b.w.). Dehydrated horses suffering from acute colitis or those which had been treated surgically for ileus of the small or large intestine were given an i.v. infusion of 10 ml HES/kg in combination with 10 ml saline/kg. Clinical data and blood samples for testing were taken before the infusion, and then 10 min, 1 h, 2, 4, 6, 8, 10, 12 and 24 h after infusion (a.i.). A significant decrease in haematocrit was observed in protocol 1-5 for a period of up to 4, 4, 10 h, 10 min and up to 10 min; in group of colitis, during the entire 24-h testing period, and in groups of ileus of small intestine and of large intestine, up to 4 and 10 h a.i. HES decreases better and longer-lasting haematocrit and total protein than either isotonic or hypertonic saline. Half-life of HES increases due to higher dosage (5.83, 7.63 and 11.48 h) and distribution is exclusively intravascular. In normal horses of protocol 1-3 using HES aPTT, sodium and potassium were within the physiological range. Serum amylase activity is increased in horses using HES. On the basis of this clinical study, the decreasing effect of urea and creatinine in colic patients after surgery and fewer instances of postoperative ileus a dosage of 10 ml HES/kg could be recommended.

Dexamethasone-induced increase in lymphocyte beta-adrenergic receptor density and cAMP formation in vivo.

The influence of dexamethasone on the density of beta(2)-adrenergic receptors (beta(2)-adrenergic receptors (beta(2)AR) and on the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) response was studied in equine lymphocytes in vivo. Dexamethasone (0.1 mg/kg/day, 1-5 days) raised the number of beta(2)AR - B(max) as assessed by (-)-[(125)I]iodocyanopindolol binding (ICYP) - to 2.5- to 3.5-fold as compared with control values. The increase in beta(2)AR number was fast (342 +/- 49 vs. 960 +/- 103 binding sites/lymphocyte after 24 h), reaching a maximum between 48 and 96 h (342 +/- 49 vs. 1,289 +/- 150 and 1,106 +/- 68 binding sites/lymphocyte, respectively). The isoprenaline-induced cAMP accumulation (measured by a [(3)H]-cAMP radioimmunoassay system) was concomitantly enhanced by dexamethasone (1.5- to 2.4-fold). Both parameters were reversible to a similar rate at dexamethasone withdrawal. The changes in the functional responsiveness of lymphocytes were not reflected by changes in the binding affinity for ICYP of beta(2)AR. These results demonstrate the in vivo glucocorticoid-mediated regulation of beta(2)AR in equine lymphocytes which has already been suggested on the basis of in vitro observations in other tissues.

Muscle thickness and neuron density in the caecum of horses with chronic recurrent caecal impaction.

In this study, the hypothesis that caecal smooth muscle layers would be thinner and the linear neuron density of myenteric plexus greater was tested in normal horses compared to those with chronic recurrent caecal impaction. Four normal horses and 18 horses with chronic recurrent caecal impaction were subjected to euthanasia and 7 tissue samples were collected from each horse at different regions of the caecum (apex, dorsal body, cranial base, dorsal base, caudal base, caudal body, ventral body). Twelve horses with chronic recurrent caecal impaction were treated surgically. Only one tissue sample of the cranial part of the caecal base close to the caecocolic orifice was taken during surgery. The thickness of the circular muscle layer of all caecal regions measured in killed horses with chronic recurrent caecal impaction was significantly increased compared to the equivalent caecal region of normal horses. On the other hand, the longitudinal muscle layer was significantly thicker only in the cranial and caudal caecal base and in the dorsal region of the caecal body. The linear neuron densities of all caecal base areas and 2 caecal body regions, the caudal body region and of the apex, of killed horses with chronic recurrent caecal impaction were significantly lower compared with those in clinically normal horses. The circular muscle layer of all caecal regions was thickened (hypertrophied) probably as a consequence of chronic uncoordinated hypercontractility due to neuron deficit in the myenteric plexus of the caecal base.

Factors associated with gastric lesions in thoroughbred racehorses.

Gastroscopic examinations were performed on 67 Thoroughbred horses in training at a race track and repeat examinations performed in 35 horses, 2 to 3 months later. Horses were age 2-9 years and included 16 two-year-olds, 32 three-year-olds and 19 horses > or = 4-years-old. Forty-two of the 67 horses had raced within the 2 months before the initial examination and the remaining 25 horses were in training. Sixty-two of the 67 horses (93%) had one or more lesions present in the gastric mucosa and lesions were present in all of the 42 horses that had raced. Thirty-two of the 35 horses, examined twice (91%), had gastric lesions on the first examination and all had lesions on the second examination. Four sites of the gastric squamous epithelium were graded for lesion severity on a scale of 0 to 10 and the mean maximum squamous mucosal lesion score was significantly (P < 0.01) greater for the second examination (4.89) than for the first examination (3.63). Maximum lesion scores were greater in 24 horses, no different in 5 horses and less in 6 horses on the second examination. The difference in mean maximum lesion scores between examinations was greatest in horses age 2 years, increasing from 1.75 to 4.00 (P = 0.014). Lesions in the gastric glandular mucosa also were scored on a scale of 0 to 10 and there was no difference in mean lesion scores in the glandular mucosa between the first and second examinations (1.89 vs. 1.90). Lesion scores were compared for gender, racing history and medication with nonsteroidal anti-inflammatory drugs, systemic corticosteroid or ACTH, or frusemide within the previous 2 months. Except for racing history, there were no significant differences in mean lesion scores for squamous or glandular mucosa based on these comparisons, indicating that there was no effect of gender or medication history on ulcer severity in the horses of our study. Mean maximum gastric squamous mucosal lesion score was significantly (P < 0.01) greater in horses that had raced (4.51) than for horses that had not raced (2.36) in the 2 months before the endoscopic examination. There was no difference in mean glandular mucosal lesion scores between horses that had raced (1.93) compared to horses that had not raced (1.13).

Measurement of 24-h gastric pH using an indwelling pH electrode in horses unfed, fed and treated with ranitidine.

A glass combined pH-reference electrode was placed in the stomachs of 5 adult horses and pH was recorded every 6 mins for 24 h while (1) feed and all bedding materials were withheld for 24 h (unfed), (2) horses had free access to Timothy grass hay for 24 h (fed), and (3) horses had free access to Timothy grass hay and were treated with ranitidine, 6.6 mg/kg body weight, orally, every 8 h for 48 h (fed + ranitidine). There was a significant (P = 0.007) difference in median 24-h gastric pH amongst the 3 protocols, the value being 3.1 in fed horses and 1.55 in unfed horses (P = 0.05) and 4.6 in fed + ranitidine horses (P = 0.05 compared with fed horses). The percentage of pH readings < 2.0 was significantly greater (P = 0.05) in unfed (76%) than in fed (30%) horses, and in fed horses than in fed + ranitidine (9%) horses. The percentage of readings > 2.0, 3.0, 4.0, 5.0 and 6.0 were each significantly (P = 0.05) greater in fed + ranitidine horses than in fed horses, and in fed than in unfed horses. There was no difference (P = 0.13) between median gastric pH values from different times of day in unfed horses (00:00 to 06:00 h, 1.5; 06:00 to 12:00 h, 1.6; 12:00 to 18:00 h, 1.7; and 18:00 to 24:00 h, 1.5). We conclude that gastric acidity is greatest when horses do not have access to feed material and that ranitidine effectively suppresses gastric acidity in horses under conditions of free access to hay.

[Plasma gastrin levels in horses with colic]. / Plasmagastrinspiegel bei Pferden mit Kolik.

The plasma gastrin levels in fasted horses (21.1 +/- 15.6 pg/ml), in horses with spasmodic colic (7.3 +/- 5.4 pg/ml) and in horses with impaction of the left ventral large colon and/or pelvic flexure (11.4 +/- 3.1 pg/ml) were not significantly different. The plasma gastrin concentrations of horses with strangulation obstruction of the small intestine, large colon displacement or adynamic ileus, and which had no gastric reflux, were 12.9 +/- 8.7 pg/ml and did not differ from fasted gastrin levels. Horses which had 5-10 litres of stomach content reflux had a higher mean gastrin level (32.2 +/- 22.6 pg/ml) (range 8.7-83.0) than the fasted horses. The mean plasma gastrin level (69.0 +/- 32.2 pg/ml) (range 27.0-122.0 pg/ml) in horses which had gastric reflux and 11-20 litres of stomach content outflow through the nasogastric tube were significantly higher (P less than 0.0004) than in fasted horses or in horses with spasmodic colic, impaction of the left ventral large colon or in horses from which no gastric reflux could be obtained.