Use of pyloroplasty (Y-U) to treat presumed delayed gastric emptying in a cheetah (Acinonyx jubatus).

A 4-yr-old cheetah (Acinonyx jubatus) with a 2-yr history of chronic intermittent vomiting and spiral bacteria-associated gastritis presented with dramatically increased vomiting frequency and marked intermittent abdominal distention. Physical examination revealed loss of muscle mass and poor fur coat quality. Contrast radiography was consistent with delayed gastric emptying due to presumed gastric outlet obstruction. Both Y-U pyloroplasty and incisional gastropexy were performed, and no subsequent vomiting has been observed for 3 yr with the exception of three episodes during the immediate postoperative period. The cause of delayed gastric emptying was not determined, although a gastric motility disorder associated with gastric bacterial infection and elevated gastrin levels was suspected.     

Gastric emptying of nondigestible radiopaque markers after circumcostal gastropexy in clinically normal dogs and dogs with gastric dilatation-volvulus.

Using radiopaque particles mixed with food, gastric emptying was assessed in healthy dogs not subjected to surgery, in healthy dogs 9 to 35 days after circumcostal gastropexy, and, in dogs 1 to 54 months after surgical treatment and recovery from gastric dilatation-volvulus (GDV). Circumcostal gastropexy surgery did not alter the 90% gastric emptying time for radiopaque particles in healthy dogs. However, 90% gastric emptying time was significantly (P less than 0.05) increased after circumcostal gastropexy in dogs with GDV, compared with healthy dogs after the same surgical procedure and recovery period. These results imply that dogs with GDV have delayed gastric emptying of solid particles. Whether delayed gastric emptying of markers detected in affected dogs after surgical treatment and recovery was the result or the cause of GDV was not determined. Results indicate that circumcostal gastropexy could be recommended as a prophylactic procedure for GDV in large breeds with deep thorax, because delayed gastric emptying of markers secondary to the surgical procedure is unlikely.     

Diagnosis and treatment of gastric motility disorders.

A disorder of gastric motility should be suspected in patients with chronic vomiting. Imaging studies are used to confirm delayed gastric emptying, the most common form of a gastric motility disorder. Other causes of chronic vomiting, for example, metabolic or endocrine disorders, other abdominal disorders, mechanical causes of gastric obstruction, and lower gastrointestinal tract disease, are then ruled out. If no underlying cause is determined, a functional disorder of gastric emptying is presumptively diagnosed. Treatment consists of dietary management and gastric prokinetic agents. Cisapride is the drug of choice for treating delayed gastric emptying followed by erythromycin and ranitidine or nizatidine.     

Gastric emptying of a radionuclide-labeled test meal after surgical correction of gastric dilatation-volvulus in dogs

Gastric emptying of a radionuclide-labeled test meal was studied in 10 dogs that had been treated surgically for gastric dilatation-volvulus and in 10 clinically normal (control) dogs. There were no significant differences between the gastric emptying rates and patterns in treated and in control dogs. Thus, there are no indications that gastric emptying is delayed in dogs that have recovered from gastric dilatation-volvulus, and there is no reason for pyloric surgery in dogs with this condition.     

Quantitative detection of atropine-delayed gastric emptying in the horse by the 13C-octanoic acid breath test

The 13C-octanoic acid breath test has been correlated significantly to radioscintigraphy for measurement of gastric emptying indices in healthy horses. The objective of this study was to investigate the validity of the test for measurement of equine delayed gastric emptying, prior to its potential clinical application for this purpose. A model of atropine-induced gastroparesis was used. Gastric emptying rate was measured twice in 8 horses using concurrent radioscintigraphy and/or breath test after treatment i.v. with either atropine (0.035 mg/kg bwt) or saline in randomised order. Analysis of both data sets demonstrated that the atropine treatment had caused a significant delay in gastric emptying rate. Paired breath test data showed an atropine-induced delay in gastric half-emptying time (t 1/2), with no overlap in the 99% CI range (P < 0.001). Significant correlations were found between scintigraphy and 13C-octanoic acid breath test for calculation of both t 1/2 (P < 0.01) and lag phase duration (P < 0.05) in the atropine-delayed emptying results. The mean (s.d.) bias in breath test t 1/2 when compared with scintigraphy was 1.78 (0.58) h. The results demonstrated that the 13C-octanoic acid breath test was an effective diagnostic modality for the measurement of equine delayed gastric emptying. The technique offers advantages to existing methods for clinical investigation, as it is noninvasive, not radioactive, quantitative and requires minimal equipment or training to perform.     

Gastric emptying of solid, non-digestible, radiopaque markers in ponies

The gastric emptying of different forms of ingesta occurs by a variety of mechanisms and dysfunction may selectively affect different components of the gastric contents. A technique for assessing gastric emptying of solid, indigestible, radiopaque markers was developed. Emptying of these markers in four ponies was variable in both pattern and rate (half emptying time ranged from less than one hour to more than 24 hours). However, whereas in man physically similar markers appear to empty relatively rapidly when fasting but are delayed by a meal, no such delay was evident in these ponies. The horse does not interrupt cyclical motility when fed ad libitum. The data, therefore, suggest that the mechanism of emptying of non-digestible markers differs between man and the pony.     

Evaluation of acetaminophen absorption in horses with experimentally induced delayed gastric emptying

OBJECTIVE: To evaluate the correlation between the half-time of liquid-phase gastric emptying (T50) determined by use of nuclear scintigraphy, using technetiumTc 99m pentetate, and absorption variables of orally administered acetaminophen in horses with experimentally delayed gastric emptying. ANIMALS: 6 mature horses. PROCEDURE: Delayed gastric emptying was induced by IV injection of atropine sulfate. Twenty minutes later, acetaminophen and technetium Tc 99m pentetate were administered simultaneously via nasogastric tube. Serial lateral images of the stomach region were obtained, using a gamma camera. Power exponential curves were used for estimation of T50 and modified R2 values for estimation of goodness-of-fit of the data. Serial serum samples were obtained, and acetaminophen concentration was determined, using fluorescence polarization immunoassay. Maximum serum concentration (Cmax), time to reach maximum serum concentration (Tmax), area under the curve for 480 minutes, and the appearance rate constant were determined, using a parameter estimation program. Correlations were calculated, using a Spearman rank correlation coefficient. RESULTS: A significant correlation was detected between T50 determined by use of scintigraphy and Tmax determined by use of acetaminophen absorption. Correlation between T50 and other absorption variables of acetaminophen was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: The acetaminophen absorption method was a valid technique in this model of delayed gastric emptying in horses. The method may be a valuable tool for use in research as well as in clinical evaluation of gastric emptying in horses.     

THE EFFECT OF INTRAVENOUS DIAZEPAM ON SOLID PHASE GASTRIC EMPTYING IN NORMAL CATS

Intravenous diazepam has been advocated as an appetite stimulant in anorexic cats. Diazepam has also been used to stimulate the intake of radiographic contrast medium-food mixture to determine the gastric emptying time of a solid meal. Diazepam has been suspected to delay gastric emptying in cats. One study found diazepam combined with Valium to have little effect on gastric transit times in cats while diazepam alone accelerates gastric emptying in humans. The purpose of this study was to determine if diazepam influences gastric emptying times in normal cats. The gastric emptying half-time of solid food in normal, non-diazepam treated cats has been previously determined using a scintigraphic technique using ^99mTc-sulfur colloid to radiolabel solid dry food. The median gastric emptying half-time was 2.3 hours and the mean meal size was 16.1 grams. Gastric emptying half-times were determined in this study using diazepam as an appetite stimulant. The median gastric emptying half-times of diazepam tratment groups given both a 16.1 gram meal and a large meal were both significantly longer than the normal non-treated group (P c 0.05). Solid phase gastric emptying is therefore significantly delayed when diazepam is used as an appetite stimulant, irrespective of the volume of the meal.     

Gastrojejunostomy as a treatment for gastric outflow disorders in four adult horses

Four adult horses with histories of moderate abdominal pain and inappetence were diagnosed with delayed gastric emptying and gastric impaction attributed to pyloroduodenal obstruction (three cases) or duodenitis (one case). A stapled side-to-side gastrojejunostomy was performed on all horses. Two horses returned to work and survived ≥3 years. One horse was euthanased 6 months post-surgery due to recurrent abdominal pain, and one was found dead 5 months postsurgery after an unattended foaling.     

Effects of indwelling nasogastric intubation on gastric emptying of a liquid marker in horses

OBJECTIVE: To determine the effects of indwelling nasogastric intubation on the gastric emptying rate of liquid in horses. ANIMALS: 6 healthy horses. PROCEDURES: Horses were assigned to treatment and control groups in a prospective randomized crossover study with a washout period of at least 4 weeks between trials. Acetaminophen (20 mg/kg) diluted in 1 L of distilled water was administered via nasogastric tube at time points of 0, 12, 30, 48, and 72 hours to evaluate the liquid-phase gastric emptying rate. In control horses, nasogastric tubes were removed after administration of acetaminophen. In horses receiving treatment, the tube was left indwelling and maintained for 72 hours. A 10-mL sample of blood was collected from a jugular vein immediately before and 20, 40, 60, 80, 100, 120, and 180 minutes after acetaminophen administration. Serum acetaminophen concentrations were measured by use of a colorimetric method. RESULTS: Peak serum acetaminophen concentration was significantly higher in the control group (38.11 microg/mL) than in the treatment group (29.09 microg/mL), and the time required to reach peak serum acetaminophen concentration was significantly shorter in the control group (22.79 minutes) than in the treatment group (35.95 minutes). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that indwelling nasogastric intubation has a delaying effect on the gastric emptying rate of liquids. Veterinarians should consider the potential for delayed gastric emptying when placing and maintaining an indwelling nasogastric tube for an extended period of time after surgery. Repeated nasogastric intubation may be better than maintenance of an indwelling tube in horses with ileus.     

GASTRIC LYMPHOSARCOMA IN A DOG: A CASE REPORT

A 9-year-old female spayed mixed-breed dog was presented with a ten-week history of vomiting. A survey abdominal radiograph showed a soft tissue mass on the lesser curvature of the stomach and an adjacent thickened greater curvature. A barium contrast study confirmed the presence of this mass. The radiographic diagnosis was gastric tumor. Radiographic signs of gastric neoplasia include soft tissue masses or thickening of the stomach wall, delayed gastric emptying, immobility of portions of the stomach wall, and residual stomach-wall staining by barium. Necropsy revealed a gastric lymphosarcoma that had infiltrated the entire circumference of the pyloric antrum. The most common gastric malignancy in the dog is adenocarcinoma. Gastric lymphosarcoma is considered rare.     

Gastric emptying of liquids in the dog: serial test meal and modified emptying-time techniques

A serial test meal technique was used in the dog to evaluate the gastric emptying of a liquid test meal. On separate days, a phenol red test meal was placed in the stomach and completely aspirated at different times. A composite representation of the gastric emptying pattern was obtained for each dog, and a set of normative data was generated. Three emptying determinants (emptying time, half-life, and starting index) were calculated. The basic pattern of canine gastric emptying was linear and declined exponentially or as a function of the square root of the gastric volume. A modified emptying-time technique (METT) correlated well with the serial test meal and a set of normative values was determined. The METT was performed by aspirating test meal from the stomach 30 minutes after instillation. The METT was a simple and inexpensive technique that could be performed in 1 short testing period. With the METT, the half-life of gastric emptying was calculated, using the log of the percentage of retention of test meal; gastric emptying time was calculated, using the square root of the percentage of retention of test meal. Acetylpromazine was shown not to alter gastric emptying of a liquid test meal.     

Nonsteroidal anti-inflammatory drugs induce hypermotilinemia and disturbance of interdigestive migrating contractions in instrumented dogs

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric ulcers due to inhibition of prostaglandin production. Prostaglandins have an influence on physiological gastrointestinal motility, but the relationships between NSAID-induced gastric ulcer, gastrointestinal motility and motilin are unknown. Fifteen dogs were allocated randomly to three groups in which either gelatin, meloxicam or indomethacin was administered. Fecal occult blood and gastrointestinal motility were monitored continuously for 6 days. In addition, analyses of the plasma motilin concentration, gastrointestinal endoscopy and gastric emptying, and detection of motilin cells were performed. Gastrointestinal motility was disturbed in the indomethacin group, presenting as disappearance of interdigestive migrating contractions (IMCs) 3 days before gastric ulcers were detected. Delayed gastric emptying and hypermotilinemia were observed significantly more often in the indomethacin group compared with the other groups. Motilin cell-crypt/villi ratio in the indomethacin group significantly decreased in the duodenum and jejunum, compared with the other groups. No significant changes in any tests were observed in the meloxicam group, when compared with the gelatin group. These findings suggest that the disturbance of IMCs caused by hypermotilinemia, with changes in motilin cell distribution, and delayed gastric emptying induced by indomethacin may contribute to the development of gastric ulcers.     

Comparison of the carbon 13-labeled octanoic acid breath test and ultrasonography for assessment of gastric emptying of a semisolid meal in dogs

OBJECTIVE: To compare the rate of gastric emptying of a semisolid meal by use of the carbon 13-labeled octanoic acid breath test (13C-OBT) and gastric emptying ultrasonography (GEU) in dogs. ANIMALS: 10 healthy dogs. PROCEDURE: Food was withheld from dogs for 12 hours before ingestion of a test meal (bread, egg, and skimmed milk) containing 13C-octanoic acid. The gastric antrum was visualized by use of a 6.5-MHz microconvex transducer, and the area of the ellipse defined by the craniocaudal and ventrodorsal diameters of the stomach was measured. Samples of expired air and antral images were obtained 30 minutes before ingestion of the test meal and then every 15 minutes for 4 hours and every 30 minutes for a further 2 hours. The half-dose recovery time with the 13C-OBT (t1/2[BT]) and the gastric half emtying time with GEU (t50%[GEU]) was calculated. RESULTS: Mean +/- SD values for the t1/2(BT) and t50%(GEU) were 3.44 +/- 0.48 hours and 1.89 +/- 0.78 hours, respectively. A significant correlation was detected between the t1/2(BT) and t50%(GEU), although there was a large (1.55 hours) mean difference between these indices. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that there was a correlation between the rate of solid-phase gastric emptying assessed by use of GEU and the 13C-OBT in dogs. Gastric emptying ultrasonography may be a useful, noninvasive method for assessment of the rate of solid-phase gastric emptying in dogs.     

Determination of solid- and liquid-phase gastric emptying half times in cats by use of nuclear scintigraphy

OBJECTIVE: To use nuclear scintigraphy to establish a range of gastric emptying half times (t1/2) following a liquid or solid meal in nonsedated cats. ANIMALS: 12 clinically normal 3-year-old domestic shorthair cats. PROCEDURE: A test meal of 75 g of scrambled eggs labeled with technetium Tc 99m tin colloid was fed to 10 of the cats, and solid-phase gastric emptying t1/2 were determined by use of nuclear scintigraphy. In a separate experiment, 8 of these cats plus an additional 2 cats were fed 18 ml (n = 5) or 36 ml (n = 5) of a nutrient liquid meal labeled with technetium Tc 99m pentetate. Liquid-phase gastric emptying t1/2 then were determined by use of scintigraphy. RESULTS: Solid-phase gastric emptying t1/2 were between 210 and 769 minutes (median, 330 minutes). Median liquid-phase gastric emptying t1/2 after ingestion of 18 or 36 ml of the test meal were 67 minutes (range, 60 to 96 minutes) and 117 minutes (range, 101 to 170 minutes), respectively. The median t1/2 determined for cats receiving 18 ml of the radiolabeled liquid was significantly less than that determined for cats receiving 36 ml of the test meal. CONCLUSIONS AND CLINICAL RELEVANCE: The protocol was tolerated by nonsedated cats. Solid-phase gastric emptying t1/2 were prolonged, compared with liquid-phase t1/2, and a major factor governing the emptying rate of liquids was the volume consumed. Nuclear scintigraphy may prove useful in assessing gastric motility disorders in cats.     

Paraesophageal hiatal hernia and pyloric obstruction in a dog

Paraesophageal hiatal herniation and pyloric obstruction were diagnosed in a pup with a history of vomiting. Findings of contrast radiography included esophageal reflux, delayed gastric emptying time, and paraesophageal herniation. Exploratory celiotomy revealed increased firmness of the pylorus and a primary defect in the esophageal hiatus, which allowed gastric herniation. Nissen fundoplication was performed following reconstruction of the esophageal hiatus, and pyloroplasty was performed to relieve the gastric outlet obstruction. Pyloric biopsy findings were consistent with a diagnosis of chronic gastritis. Recovery from surgery was initially unremarkable; however, the dog died suddenly 3 weeks after surgery. Necropsy revealed a large diaphragmatic hernia adjacent to the esophageal hiatus; the hernia had resulted in incarceration of the abdominal organs. The hiatal hernia reconstruction remained intact and was not the cause of the diaphragmatic disruption.     

COMPARISON OF THE EFFECT OF LAPAROSCOPIC AND CONVENTIONAL PYLORIC SURGERY ON GASTRIC EMPTYING IN DOGS

The effect of a laparoscopic approach and pyloric surgery on canine gastrointestinal activity, particularly gastric emptying time, is not well understood. The purpose of this study was to compare the effect of laparoscopic and conventional pyloric surgery, in Ramstedt pyloromyotomy and Heineke-Mikulicz pyloroplasty, on complete gastric emptying time in 20 clinically normal dogs. Dogs were divided into four groups of five animals: dogs with laparoscopic Ramstedt pyloromyotomy, conventional Ramstedt pyloromyotomy, or laparoscopic Heineke-Mikulicz pyloroplasty, and the conventional Heineke-Mikulicz pyloroplasty group. Gastric emptying time using barium sulfate mixed with dry kibble dog food was measured fluoroscopically before and 1 month after surgery. Gastric emptying of solids was significantly enhanced in the pyloroplasty groups in the postoperative period compared with preoperative emptying. Just as after conventional pyloromyotomy, gastric emptying time after laparoscopic pyloromyotomy was not statistically different as compared with preoperative values. This study indicates that the fluoroscopic test meal is a valuable tool for defining complete gastric emptying time in normal dogs. We conclude that pyloromyotomy was less effective in decreasing complete gastric emptying time than Heineke-Mikulicz pyloroplasty in normal dogs. The possibility of decreasing complete gastric emptying time by laparoscopic surgery suggests a potential clinical application for this technique in small animals.     

Gastrointestinal motility disorders and gastrointestinal prokinetic therapy.

Gastrointestinal motility disorders represent a diagnostic and therapeutic challenge. Disorders of gastrointestinal motility may result in accelerated transit, delayed transit, impaired relaxation, or inappropriate relaxation. The delayed transit disorders are the most important motility disorders of companion animals and may involve the esophagus (hypomotility and megaesophagus), stomach (delayed gastric emptying), small intestine (postoperative ileus and intestinal pseudo-obstruction), or colon (constipation and megacolon).     

Influence of dietary composition on gastric emptying and motility in dogs: potential involvement in acute gastric dilatation

Gastric dilatation-volvulus is a dramatic and life-threatening disease of large-breed dogs. The cause is unknown, but ingestion of dry cereal-based food is frequently incriminated as a predisposing factor. The purpose of this study was to examine the effect of commercial diets on gastric motility and emptying in the dog. Four large-breed dogs were fed 3 different diets (diet A = canned meat-based; B = cereal-based with 77% added water; and C = dry cereal-based) in a randomized block design. Each experiment was done in triplicate. Motility was assessed, using 5 AgAgCl electrodes and 2 strain gauges sutured along the serosa of the stomach and proximal duodenum. Dogs were fed at the same time each day and the time to change from the fed to the fasted pattern of gastrointestinal motility (changeover) was measured. Gastric emptying was assessed by recording gastric radioactivity. After feeding a meal mixed with 99mTc-labeled resin, the log of activity was plotted against time, and the half-time of gastric emptying (t1/2 GE) was calculated. Mean (+/- SEM) times from feeding to changeover for the 3 diets were: diet A, 9.7 +/- 0.9; B, 10.5 +/- 0.4; and C, 11.0 +/- 0.8 hours. Diet had minimal influence on the half time of gastric emptying (diet A, 2.2 +/- 0.3; B, 2.6 +/- 0.4; and C, 2.9 +/- 0.3 hours; P greater than 0.05). The data indicate that gastric motility and emptying in healthy large-breed dogs were not affected by dietary composition. Because most large dogs are fed cereal-based food for reasons of cost and ease of use, these diets may have been wrongly incriminated as a predisposing factor in gastric dilatation-volvulus.     

Effect of body size on gastric emptying using the 13C-octanoic acid breath test

The 13C-octanoic acid breath test (OABT) may be a useful non-invasive method for assessing the rate of gastric emptying in dogs. The aim of this study was to determine whether an association exists between body size and rate of gastric emptying in dogs. Fifty-five dogs ranging from 6 to 39 kg were recruited and rate of gastric emptying was assessed using the OABT. The time to peak 13CO2 excretion (tmax) and half-dose recovery time (t1/2) were calculated. The OABT was simple to perform and well tolerated by the dogs. Mean (sd) tmax was 2.67 hours (0.6) and mean t1/2 was 3.38 hours (0.79). Inter-individual variation in the rate of gastric emptying was 23.3 per cent for t1/2 and 22.5 per cent for tmax. No association was detected between the rate of gastric emptying and body surface area, mass, age, sex or test operator. The OABT may be a useful non-invasive and non-radioactive test for assessment of the rate of gastric emptying in dogs in clinical practice.