THE USE OF A BARIUM MEAL TO EVALUATE TOTAL GASTRIC EMPTYING TIME IN THE DOG JOANNE BURNS,DVM, STEVENM. Fox, DVM, MS
Total gastric emptying time was determinedin nine mongreldogs using a barium meal contrast procedure. Within the group, total gastric emptying time ranged from 7.0-15.0 hours. Comparison of the population mean showed a statistical difference (p = 0.01) from previously published values. Individual dogs showed consistent total gastric emptying time over three trials. The technique can be used to test the effect of a procedure on total gastric emptying time when a normal value has been established for the dog. Due to the wide range of normal values observed, evaluationof clinical patients could be difficult unless there is a gross abnormalityin function. VeterinaryRudiology, V O ~27, . NO. 6, 1986;p p 169- 172. Key words: dog, gastric emptying, barium contrast.
G
is a complex event governed by neural and hormonal mechanisms. In dogs, the rate of gastric emptying is directly influenced by pressure differences and the degree of resistance at the gastroduodenal junction.' Alterations from normal gastric emptying times can indicate significant pathologic abnormalities, including pyloric outlet obstruction, hypertrophic gastritis,* protruding neoplasia, or nerve dysfunction. Pyloric sphincter dysfunction has been implicated as a contributing factor in gastic dilatationvolvulus.3-~ Total gastric emptying time with liquid barium upper gastrointestinal studies in the normal dog is between 1-4 hours.6~~ Liquids are separated from solids in the stomach and emptied at a faster rate, while solids are retained for further digestion and emptied at a linear-exponential rate.8,9Recently, interest has been shown in developing a reliable, practical method to evaluate the rate of gastric emptying and total gastric emptying time in dogs consuming a semisolid meal. Radioisotope studies have been used to evaluate the rate of gastric emptying,9J0 and barium-food mixtures have been used to evaluate total gastric emptying time." These studies have been directed toward establishing normal values as an aid in the diagnosis of gastric motility disorders and pyloric dysfunction. The objectives of this project were to evaluate total gastric emptying time in a group of normal mongrel dogs using a barium-food mixture, to compare these values to previously published data on a small group of purebreed beagles," and to evaluate the practicality of this technique to detect alterations in total gastric emptying time in clinical situations.
MATERIALS AND METHODS
ASTRIC EMPTYING
From the College of Veterinary Medicine, Mississippi State. Funded by College of Veterinary Medicine grant 330-85-1.6. Address correspondenceand Reprint requests to Dr. Joanne Bums, College of Veterinary Medicine, Drawer V, Mississippi State, MS 39762.
Experimental Animals Four male and five female, adult, mixed breed dogs with weights ranging from 14.5-20.5 kg were used for the study. All dogs were housed in the Animal Health Center at Mississippi State University, College of Veterinary Medicine. Prior to being admitted to the study, each dog had a normal physical exam, CBC, and serum biochemical profile. Modified Knott's test and fecal flotation were negative. A liquid barium sulfate gastrointestinalexamination was performed on each dog prior to being admitted to this study, and was normal in all dogs. At least 1 week prior to the normal meal studies, laporatomies were done to place radiopaque markers at the pylorus. Two stainless steel sutures were placed approximately 3 cm cranial and caudal to the pylorus. The sturctures were placed with minimal seromuscular purchase in both the mesenteric and antimesenteric borders, so as to be of benign influence to normal physiologic function.
Test Meals Dogs were preconditioned with a diet of ground kibble* passed through a feed mill to create a particle size of less then 1 mm. No palatability problems were observed. The contrast meal consisted of 7 ml per kg body weight barium sulfate? mixed with 8 gm per kg body weight ground kibble.
*Purina Field 'n Farm Dog Food, Ralston Purina Company, St. Louis, MO 63155. TNovapaque, 60%w/v barium sulfate suspension,Picker Corporation, Cleveland, OH 44101.
169
170
BURNSAND FOX
Experimental Methods Three studies were done on each dog to establish a mean total gastric emptying time for each individual. Studies were repeated at no less than 72-hour intervals. Dogs were fasted 24 hours prior to the study, and water was offered free choice. No additional food or water was offered during the course of the radiographic study. A preprandial radiograph was taken prior to feeding the meal to establish the presence of an empty stom-
FIG. 1. Dog #2899: ventrodorsal views of the abdomen. (A) The 15-minute radiograph shows a homogeneous pattern of the barium meal in the fundus of the stomach and the presence of contrast medium in the proximal small bowel. Wire sutures are present in the pyloric region to aid in localization of the pyloric sphincter. (B) At 3 hours, there is even distribution of the barium meal throughout the gastrointestinal tract. (C) The 7-hour study shows a small amount of contrast medium in the stomach and a partially empty duodenum and jejunum. (D) At 8 hours, the stomach, duodenum, and jejunum are empty. Contrast medium is still in the ileum.
1986
ach. Postprandial radiographs were made at 15 minutes, 1 hour, 3 hours, 6 hours, and 9 hours. Additional hourly radiographs were made when gastric emptying was thought to be nearly complete. Position of the dogs for radiographic exam was selected to reduce excitation and to maximize visualization ofthe stomach. Total gastric emptying time was defined as no contrast meal being present in the stomach, and examinations were stopped at that time (Fig. I).
VOL.27, No. 6
NORMAL GASTRIC EMPTYING TIME Results
TABLE1. Total Gastric Emptying Times. ~~
The total gastric emptying time for each trial and the mean total gastric emptying time of each dog were calculated using Data General Computer and SAS analysis (Table 1). A two sample t-test comparing the mean gastric emptying times between this study and that of Miyabayashi and Morgan" revealed a significant difference at the p = 0.0 1 level (Table 2).
Discussion Positioning of the animals was not critical until the last radiographs of each series. Ventrodorsal, dorsoventral, and right recumbent lateral views were used interchangably. The dorsoventral view was initially preferred, due to the gravitational pooling of contrast medium in the pylorus. However, problems arose in visualizing the pyloric area of deep-chested dogs due to the overlying barium-filled colon. Therefore, in the later stages of the study, the ventrodorsal view was used to evaluate total gastric emptying time. No sedation was used to position the dogs, and they were handled in a routine manner for abdominal radiography. The test meal was readily eaten by most of the dogs. One dog was slow to consume the meal and, during some trials, had to be force fed. The dog had an empty stomach on preprandial study, and was fed a meal mixture prepared in a uniform manner to other dogs being studied that day. Force feeding boluses seemed to change the appearance of the meal to a clumped rather than a homogeneous food pattern as seen in the other dogs (Fig. 2). Onset of gastric emptying was observed within 1 hour in all trials, indicating normal function of the distal stomach."
FIG.2. Dog #2783: ventrodorsal view of the abdomen. The I-hour study shows clumping of the contrast meal following force feeding. This pattern persisted throughout the study, but did not appear to effect total gastric emptying time. Wire sutures are present to aid in localization of the pyloric sphincter.
171
~~
~~
~
~~
~~
~~
Trial 2 (Hm)
Trial 3 (Hm)
Mean
Dog
Trial 1 (Hm)
2894 2857 2899 2783 2697 2873 2720 58 2576
14.0 8.0 8.0 15.0 12.0 12.0 12.0 11.0 13.5
13.5 7.0 7.0 14.5 12.5 9.0 11.5 11.0 13.0
13.0 7.5 9.0 13.5 10.0 8.0 9.0 10.0 10.0
13.5 7.5 8.0 14.3 11.5 9.6 10.8 10.6 12.1
SD*
(Hrs) 0.5 0.5
1.o
0.8 1.3 2.1 1.6 0.6 1.9
*SD = Standard Deviation TABLE2. Comparison of Mean Values for Total Gastric Emptying Time. Study Miyabayashi and Morgan Bums and Fox
Number of Dogs
Mean
SEM*
4
7.00 10.9
.74t .76
9
*SEM = Standard Error of the Mean. ?Value for SEM was incorrect in original publication. This value represents SEM recalculated by Miyabayashi.
The radiographic procedure followed the protocol of Miyabayashi and Morgan, with the hope of duplicating their data and enlarging the number of animals studied in this manner. Comparison between means of the two populations revealed a significant difference (p = .O l), which prevents combining the two populations. Several factors may have contributed to that difference. Morgan and Miyabayashi used a homogeneous population of four young Beagles and reported a more narrow range of
172
BURNSAND Fox
values (5 - 9 hours) using a ground kibble-barium mixture. The dogs in this population were approximately twice the weight of those used by Miyabayashi and Morgan, and were of mixed hound breeding. The dose ofthe barium meal was not adjusted for body weight, and could have resulted in longer total gastric emptying times. Laporatomies done 2 weeks prior to the baseline studies were necessary to mark the pyloris for later evaluation of the effect of pyloric surgery.12Although the sutures were placed to minimize the effect on pyloric function, it did result in a population of dogs which had undergone recent abdominal surgery. The contrast procedure is practical, and could be done in a practice setting. However, due to the wide range of normal
1986
values observed, accurate evaluation of clinical patients suspected of gastric abnormalities could be difficult unless there is gross abnormality in function. A day-to-day consistency in gastric emptying time within individual dogs has been r e p ~ r t e d . ~ Data J ~ J ~from this study supports that observation. The technique is useful to evaluate the effect of a procedure or drug on the total gastric emptying time once a control value has been established for that individual.12
ACKNOWLEDGEMENT The authors would like to acknowledgeCarolyn R. Boyle for statistical analysis and Monique Leckrone for coordinating animal care.
REFERENCES I . Kelly KA. Motility of the stomach andgastroduodenal junction. In: Johnson LR, ed. Physiology of the gastrointestinal tract. New York Raven Press, 1981: 393-410. 2. Happe RP, Van den Brom WE, Van der Gaay L. Duodenogastricreflux in the dog, a clinicopathologicalstudy. Res Vet Sci 1982; 33:280-6. 3. Wingfield WE, Betts CW, Rawlings CA. Pathophysiology associated with gastric dilation-volvulus in the dog. J Am An Hosp Assoc 1976;12:136-42. 4. Andrew AH. A study often cases ofgastric torsion in the Bloodhound. Vet Rec 1970; 86:689-93. 5. Funkquist B. Gastric torsion in the dog: nonsurgical reposition. J Small Anim Pract 1969; 10507- 1 1. 6. Funkquist B, Garmer L. Pathogeneticand therapeuticaspectsoftorsionof the canine stomach. J Small Anim Pract 1967; 8:523-32. 7. OBrien TR. Radiographic diagnosis of abdominal disorders in the dog and cat. Philadelphia: WB Saunders Co, 1978; 257.
8. Hinder RA, Kelly KA. Caninegastricemptying of solidsand liquids. Am J Physiol 1977; 233E335-40. 9. Theodorakis MC. External scintigraphy in measuringrate ofgastric emptying in beagles. Am J Physiol 1980; 239:G39-43. 10. Koblik PD, Hornoff WJ. Gastrointestinal nuclear medicine. Vet Rad 1985; 26:138-42. 1 1. Miyabayashi T, Morgan JP. Gastric emptying in the normal dog: a contrast radiographic technique. Vet Rad 1984; 25:187-91. 12. FoxS, BurnsJ.Theeffect ofpyloricsurgeryongastricemptyinginthedog: Comparison of three techniques. J Am An Hosp Assoc (in press). 13. Kelly KA, Code CF, Elveback LR. Patterns of canine gastric electrical activity. Am J Physiol 1969; 2 17:461-70. 14. Itoh Z, Aizawa I, Takeuchi S, et al. Diurnal changes in gastric motor activity in conscious dogs. Am J Dig Dis 1977; 22:117-24.