ULTRASONOGRAPHY OF THE NORMAL CANINE GASTROINTESTINAL TRACT

The normal sonographic appearance of stomach, small bowel, and colon was determined in normal dogs of small, medium, and large breeds. In all dogs studied, the stomach wall ranged from 3 mm to 5 mm in thickness, and the small and large bowel wall ranged from 2 mm to 3 mm in thickness. Peristalsis was routinely observed in the stomach and small bowel, but not in the colon. Ultrasonic identification of five gastrointestinal wall layers corresponding to the mucosal surface, mucosa, submucosa, muscularis propria, and subserosa/serosa was possible. Specific segments of the gastrointestinal (GI) tract were isolated and scanned in a water bath. In one dog, ultrasonic and histologic findings were compared and confirmed the anatomical identification found with ultrasound. Similarities and differences between the ultrasonic appearance of the GI tract of humans and small animals are discussed.     

NORMAL CANINE PEDIATRIC GASTROINTESTINAL ULTRASONOGRAPHY

The normal sonographic appearance of the adult canine gastrointestinal tract has been described. Interpretation of abdominal ultrasonographic findings in puppies is difficult due to the lack of information on normal ultrasonographic findings. The gastrointestinal tract, jejunal lymph node size and the presence and appearance of abdominal fluid were investigated in 23 normal, 7–12-week-old Beagle puppies. The duodenal wall thickness was greater than in other parts of the gastrointestinal tract (mean 3.8 ± standard deviation [SD] 5 mm, range 3.2–4.8 mm). The mean stomach wall thickness was 2.7 ± SD 0.4 mm (range 2.2–3.7 mm), the mean jejunal wall thickness was 2.5 ± SD 0.5 mm (range 1.2–3.4 mm), and the mean colonic wall thickness was 1.3 ± SD 0.3 mm (range 0.7–2.0 mm). In addition, mean duodenal and jejunal mucosal layer thicknesses measured 2.7 ± SD 0.5 mm (range 2.0–3.8 mm) and 1.5 ± SD 0.4 mm (range 0.6–2.5 mm), respectively. Homogenous, hypoechoic jejunal lymph nodes were easily found and the mean thickness was 7.1 ± SD 2.2 mm (range 1.5–12.5 mm). A mild amount of anechoic free peritoneal fluid was present in all puppies.     

THE NORMAL UPPER GASTROINTESTINAL EXAMINATION IN THE FERRET

Upper gastrointestinal examinations were performed in 11 unsedated ferrets and 4 ferrets sedated with ketamine and diazepam. Each animal received a 8-13 mL/kg body weight dosage of barium liquid (30% weight:volume). Radiographs were made immediately and at 5, 10, 20, 40, 60, 90, 120 and 150 min (mins) after the barium was administered. Gastric emptying began immediately. Mean total gastric emptying was longer in sedated ferrets (130 +/- 40 min versus 75 +/- 54 min); however, this difference was not statistically significant (p = 0.18). Small intestinal transit time was less than 2 h in all ferrets. The barium-filled small bowel was best visualized on the 20- and 40-min radiographs and did not exceed 5-7 mm in width. Flocculation of barium in the small intestine and adherence of barium to the stomach mucosa was seen in almost all animals. The longitudinal colonic mucosal folds in the colon were well visualized in the normal upper gastrointestinal study and aided in distinguishing small intestine from large intestine. The use of ketamine and diazepam sedation did not significantly affect the parameters evaluated in the upper gastrointestinal study series.     

Reference Values and Repeatability of Transabdominal Ultrasonographic Gastrointestinal Tract Thickness and Motility in Healthy Donkeys (Equus asinus)

The present study aimed to provide reference ranges for the wall thickness and motility pattern of the gastrointestinal tract from a sample of donkeys (Equus asinus) population using B-mode ultrasonography. In the present study, 30 clinically healthy donkeys (Equus asinus) (15 males and 15 females), aged 2–20 year old and weighed 100–280 kg were randomly selected for B-mode ultrasonographic scanning of the abdomen. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was assessed. Moreover, the motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was evaluated over a period of 3 minutes. Abdominal ultrasonographic scanning of the gastrointestinal tract of healthy donkeys explored that the stomach, duodenum, jejunum, left colon, right colon, and cecum could be visualized easily. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was 7.0 ± 0.9 mm, 3.3 ± 1.0 mm, 5.4 ± 0.6 mm, 5.1 ± 0.5 mm, 5.4 ± 0.5 mm, and 5.4 ± 0.6 mm, respectively. The thickest part of the gastrointestinal tract is the stomach, whereas the thinnest part is the duodenum. The motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was 7.7 ± 1.3 contractions/3 minutes, 6.9 ± 1.1 contractions/3 minutes, 4.1 ± 1.2 contractions/3 minutes, 5.5 ± 1.3 contractions/3 minutes, and 4.0 ± 0.8 contractions/3 minutes, respectively. Both the duodenum and jejunum contractions were significantly higher than that of the left colon, right colon, and cecum. This is the first study reporting the reference values for both the wall thickness and motility pattern of the gastrointestinal tract in healthy donkeys (Equus asinus) in Egypt. Good knowledge of these standard and reference values of the wall thickness and motility pattern of gastrointestinal tract structures represents a step in the early diagnosis of the gastrointestinal disorders, including colic in such animal species.     

Gastrointestinal Ultrasonography of Normal Standardbred Neonates and Frequency of Asymptomatic Intussusceptions

Background

Ultrasonographic appearance of the gastrointestinal (GI) tract of equine neonates has not been completely described.

Objectives

To describe (1) sonographic characteristics of the GI segments in normal nonsedated equine neonates, (2) intra‐ and interobserver variation in wall thickness, and (3) the sonographic appearance of asymptomatic intussusceptions, and (4) to compare age and sonographic findings of foals with and without asymptomatic intussusceptions.

Animals

Eighteen healthy Standardbred foals ≤5 days of age.

Methods

Prospective, cross‐sectional blinded study. Gastrointestinal sonograms were performed stall‐side. Intraobserver variability in wall thickness measurements was determined by calculating the coefficient of variation (CV). The Bland–Altman method was used to assess interobserver bias. Student''s t‐test and Fisher''s exact test were used to test the association among presence of intussusceptions, age, and selected sonographic findings.

Results

The reference ranges (95% predictive interval) for wall thickness were 1.6–3.6 mm for the stomach, 1.9–3.2 mm for the duodenum, 1.9–3.1 mm for the jejunum, 1.3–2.2 mm for the colon, and 0.8–2.7 mm for the cecum. Intraobserver wall thickness CV ranged from 8 to 21% for the 2 observers for 5 gastrointestinal segments. The interobserver bias for wall thickness measurements was not significant except for the stomach (0.14 mm, P < .05) and duodenum (0.29 mm, P < .05). Diagnostic images of mural blood flow could not be obtained. Asymptomatic intussusceptions were found in 10/18 neonates. Associations between sonographic variables or age and the presence of intussusceptions were not found.

Conclusions and Clinical Importance

Sonographic characteristics of the GI tract of normal Standardbred neonates can be useful in evaluating ill foals. Asymptomatic small intestinal intussusceptions occur in normal Standardbred neonates.     

ULTRASONOGRAPHIC APPEARANCE OF FELINE ALIMENTARY LYMPHOMA

Abdominal ultrasonography was performed in seven cats with intestinal lymphoma and four cats with gastric lymphoma. Ultrasonographic abnormalities included the presence of a hypoechoic mass associated with the gastrointestinal tract, focal or diffuse thickening of the gastric wall, symmetric thickening of the bowel wall, loss of the normal layered appearance of the gastrointestinal wall, and abdominal lymphadenopathy. The thickness of the stomach wall ranged from 8 to 22 mm in cats with gastric lymphoma, and the thickness of the bowel wall ranged from 5 to 20 mm in cats with intestinal lymphoma. Fine needle aspiration of a gastrointestinal lesion was performed without complication in six cats, and was diagnostic for lymphoma in five out of six. Results of this study indicate that ultrasonography is an effective noninvasive means of identifying lesions consistent with alimentary lymphoma in cats.     

Cecal impaction due to dysautonomia in a llama (Lama glama).

A llama (Lama glama) died after 1 wk of obstipation, lethargy, and rolling. Necropsy showed that the stomach and small intestine were distended with gas and fluid. The cecum was impacted with dry contents and the colon was empty. No gross lesions were found in the wall of the gastrointestinal tract or other organs. Histologic changes consisted of chromatolysis of neurons of autonomic ganglia, enteric plexi, and the accessory cuneate nucleus, consistent with lesions associated with dysautonomia in other domestic animals.     

Investigation of scan delays for CT evaluation of inner wall layering and peak enhancement of the canine stomach and small intestine using a 20 second fixed-injection-duration and bolus tracking technique

Many gastrointestinal diseases affect the mucosal layer, suggesting that on computed tomography (CT) examination, detection of consistent inner wall layering of the gastrointestinal tract may aid in detection of disease. Changes in wall enhancement can also characterise specific diseases and provide prognostic information. The objectives of this mixed retrospective and prospective analytical study were therefore to identify the scan delays for peak detection of canine stomach and small intestinal inner wall layering and enhancement when using a 20 s fixed-injection-duration and bolus tracking technique. For each patient, 700 mg I/kg iohexol was administered intravenously. Bolus tracking was used to determine aortic arrival. Diagnostic scans were performed after a post-aortic arrival scan delay. Postcontrast CT series were grouped according to post-aortic arrival scan delay: 5 s (n = 17), 10 s (n = 18), 15 s (n = 23), 20 s (n = 10), 25 s (n = 6), 30 s (n = 14), 35 s (n = 17), 40 s (n = 24), and 180 s (n = 60). The stomach and small intestine were assessed for the presence of a contrast-enhancing inner wall layer and wall enhancement. Statistical modeling showed that the scan delays for peak inner wall layering and enhancement were 10 and 15 s for the small intestine, respectively, and 40 s for the stomach. For the injection protocol used in this study, assessment of the canine gastrointestinal tract may use scan delays of 10–15 s and 40 s.     

高原鼠兔和高原鼢鼠胃肠组织形态比较研究

为探究高原鼠兔(Ochotona curzoniae)与高原鼢鼠(Eospalax baileyi)胃肠道形态在高原恶劣环境中对食物资源和能量需求的适应对策,将捕获于青藏高原高寒草甸的高原鼠兔(8 ♀,7 ♂)和高原鼢鼠(9♀,6 ♂)解剖后,测定其胃肠道形态指标,采用独立样本t检验和协方差分析进行对比。结果显示,两种动物胃肠道形态在种内性别间差异表现为雄性高原鼠兔小肠长度、盲肠鲜重显著大于雌性(P＜0.05),雄性高原鼢鼠小肠和盲肠长度、大肠鲜重及胃和大肠净鲜重显著高于雌性(P＜0.05)。在种间水平上,高原鼠兔小肠和盲肠长度、盲肠净鲜重显著大于高原鼢鼠(P＜0.05),而其胃和大肠长度、大肠鲜重显著小于高原鼢鼠(P＜0.05)。研究表明,高原鼠兔和高原鼢鼠的前肠和后肠因其种间能量需求和食性的不同存在代偿性差异;同一物种雌、雄个体均通过改变小肠长度来适应性别间差异化的能量需求。     

Ultrasonographic intestinal muscularis thickening in dogs with histologically confirmed inflammatory bowel disease: 13 cases (2010–2021)

Ultrasonographic intestinal muscularis thickening has not been described as an imaging feature of canine inflammatory bowel disease. In this retrospective case series, patients were identified by searching sonographic reports for “muscularis” and/or “muscular layer.” Patients were included if small intestinal muscularis thickening was reported, and sonographic images and histopathological samples of the small intestine were available for review. Cases with small intestines nodules, masses, or complete loss of wall layering were excluded. Sonographic images were retrospectively evaluated for jejunal muscularis layer thickness, and ratios of intestinal layer measurements were performed. Histological samples were retrospectively reviewed. Thirteen dogs met inclusion criteria: all dogs had sonographic intestinal muscularis thickening relative to the submucosa (>1.0, range of 1.3–2.5), and most dogs had muscular layer thickness above normal published ranges (11/13; all 13/13 above the weight-specific mean). More than half of the patients had overall normal wall thickness (11/13) and several had normal mucosal echogenicity (6/13). Therefore, in some dogs, the only sonographic abnormality in the small intestine was muscularis thickening. No dogs had lymphadenomegaly. Endoscopic partial-thickness (n = 11, duodenum and/or ileum) or surgical full-thickness (n = 2) samples confirmed inflammatory bowel disease. Direct comparison between jejunum sonographic characteristics and histology features was limited due to both partial thickness biopsies and lack of direct comparison between anatomical locations of ultrasonographic assessment and biopsy site. However, no cases that met the inclusion criteria had normal small intestinal histology. Comparable to cats, dogs with ultrasonographic intestinal muscularis thickening may have inflammatory bowel disease, and further workup for enteropathy is indicated.     

SONOGRAPHIC INVESTIGATIONS OF THE GASTROINTESTINAL TRACT OF GRANIVOROUS BIRDS

This article describes the sonographic examination of the normal gastrointestinal tract of granivorous birds. Preliminary tests with dead birds were performed to get an idea of the sonographic echotexture of the avian gastrointestinal tract. Later, clinically healthy seedeaters of different weights were examined sonographically. As equipment a convex microcurved scanner with a particularly small coupling surface and an adjustable frequency from 5.5-7.5 MHz was used. For the investigation of the gastrointestinal tract, six sonographic approaches are described. After a starving time of 18 hours in the granivorous birds and water input, the best sonographic image quality could be obtained. Using this method, the crop, ventriculus, intestines, and cloaca could be demonstrated sonographically; whereas, it was not possible to visualize the normal proventriculus in granivorous birds. In contrast to mammals, the different layers of the wall of the gastrointestinal tract could not be visualized with the equipment used. Motility of individual parts of the gastrointestinal tract (GI tract), however, could be well demonstrated.     

Ultrasonography of the gastrointestinal tract of toco toucans (Ramphastos toco)

Baseline data for wall thickness in healthy toucans can be used to diagnose disease in sick individuals. This study aimed to evaluate the use of ultrasonography for the examination of the gastrointestinal tract of healthy toco toucans (Ramphastos toco). Ten non-anaesthetized healthy adult toco toucans were evaluated. Food was withheld for 3 h prior to the ultrasound examination. Longitudinal and transverse images of the gastrointestinal tract were obtained using ventromedian cranial and ventromedian caudal approaches to evaluate the morphology and stratification. The wall thickness of the sections was measured: proventriculus and ventriculus, duodenum, jejunum/ileum, and cloaca. Additionally, the thickness of the mucosal layer of the duodenum and jejunum/ileum was also measured. Subsequently, the ratios of the duodenal wall thickness to the duodenal mucosa layer and the total wall thickness of the jejunum/ileum to the jejunum/ileum layer mucosa were stablished. The wall thickness of the proventriculus was significantly higher than the wall thickness of ventriculus. The wall thickness of the duodenum was significantly higher than the wall thickness of jejunum/ileum. The mean ratios of the duodenal wall thickness to the duodenal mucosa layer and the wall thickness of the jejunum/ileum to the jejunum/ileum layer were 83.15% and 80.07%, respectively. In conclusion, it was possible to assess the stomach and intestines using ultrasound examination in healthy toco toucans, due to their medium body size and no interference by surrounding air sacs.     

COMPARATIVE ULTRASONOGRAPHIC INVESTIGATIONS OF THE GASTROINTESTINAL TRACT AND THE LIVER IN HEALTHY AND DISEASED PIGEONS

The use of ultrasound as a diagnostic tool in birds has been documented for cardiac, urogenital, and liver disease. However, its use in gastrointestinal tract disease is not defined. Therefore, the purpose of this study was to compare the ultrasonographic findings of the intestine and liver of six healthy racing pigeons with those of six racing pigeons with gastrointestinal disease. The echogenicity of the liver was significantly different between the two groups. Pigeons with gastrointestinal disease had less homogeneous liver echogenicity with focal heterogeneous areas and the hepatic blood vessels were visible and dilated. The duodenum was visualized and its mean diameter of 7.2 +/- 0.3 mm in the diseased pigeons was significantly wider (P < or = 0.001) than the 5.7 +/- 0.2 mm in healthy birds. The thickness of the duodenal wall in healthy and diseased pigeons was 1.6 +/- 0.1 and 2.4 +/- 0.1 mm, respectively, and they were significantly different (P < or = 0.001). We defined baseline measurements for the duodenal loop in pigeons and provided evidence that ultrasound can be a useful diagnostic tool for investigating intestinal disease in pigeons.     

THE SONOGRAPHIC APPEARANCE OF INTESTINAL MUCOSAL FIBROSIS IN CATS

The medical records of 11 cats with full‐thickness intestinal biopsies and histopathologic confirmation of segmental mucosal fibrosis were reviewed. All cats received an abdominal ultrasonographic evaluation. The sonographic feature of a small intestinal mucosal hyperechoic band paralleling the submucosa was present in all cats. Other intestinal sonographic findings included wall thickening, and altered wall layering (increased mucosal echogenicity, thickened submucosa, and/or muscularis layer). None of the cats had complete loss of wall stratification. All cats had clinical signs related to the gastrointestinal (GI) tract at the time of presentation. Three of the 11 cats had palpably thickened small intestinal loops, 3/11 abdominal pain, and 2/11 abdominal fluid. Histopathologically, mucosal fibrosis was associated with inflammatory cell infiltrates in all cats. In those cats with histopathologic evidence of mural fibrosis, all cats had a visible hyperechoic band through several intestinal segments. We speculate that the hyperechoic mucosal band represents the zone of mucosal fibrosis. Independently and prospectively, we reviewed the clinical presentation of 35 cats having this visible hyperechoic mucosal band on ultrasound. Twenty‐four of these 35 cats had clinical signs related to the digestive system at the time of record. Our study suggests that the hyperechoic mucosal band represents fibrosis, and in presence of concurrent GI signs, further diagnostic tests may be warranted.     

Immunohistochemical study on the distribution of endocrine cells in the gastrointestinal tract of the babirusa, Babyrousa babyrussa (Suidae)

The distribution and relative frequency of endocrine cells in the gastrointestinal tract of the babirusa were studied immunohistochemically using the avidin-biotin-peroxidase complex method. Thirteen types of gut endocrine cells were detected; they were immunoreactive for chromogranin, serotonin, somatostatin, gastrin, bovine pancreatic polypeptide (BPP), glucagon, secretin, cholecystokinin (CCK), methionine-enkephalin-Arg6-Gly7-Leu8 (MENK8), motilin, gastric inhibitory polypeptide (GIP) and peptide tyrosine tyrosine (PYY). Cells that were immunoreactive for chromogranin, serotonin, somatostatin and glucagon were found in all portions of the gastrointestinal tract. MENK8-immunoreactive cells were observed in the stomach and small intestine. Gastrin-immunoreactive cells were detected in the pyloric region and duodenum. PYY-immunoreactive cells were found in the small and large intestine. Cells immunoreactive for motilin, CCK, GIP, and secretin were observed in the proximal small intestine and those immunoreactive for neurotensin were found only in the ileum. Although the distribution pattern of endocrine cells in the gastrointestinal tract of babirusa was similar to those reported for pig, restricted distribution of several endocrine cells, gastrin, BPP, MENK8, motilin, CCK, GIP, secretin and neurotensin and wider distribution of glucagon and PYY were observed in the babirusa. The unexpected presence of MENK8 in all glandular regions of the stomach and PYY in the small intestine was also noted. The distribution of gut endocrine cells might be related to the regulatory characteristics of the babirusa digestive tract.     

麻雀消化道在繁殖期间形态变化及适应意义

对20只繁殖期前和20只繁殖期麻雀进行体尺测量和消化道各组织器官长度及重量测定,观察其胃、小肠、大肠在繁殖期前和繁殖期的长度、鲜重及干重变化情况。试验结果表明:繁殖期麻雀与繁殖期前相比,麻雀胃的长度、含内容物重、不含内容物重分别增加了12.66%、10.42%和4.76%,差异极显著(P<0.01);干重比繁殖期前增加了8.33%,差异显著(P<0.05)。小肠的长度、含内容物重、不含内容物重、干重分别增加了9.43%、68.18%、75.00%和83.33%,差异极显著(P<0.01)。大肠长度增加了2.48%,差异不显著(P>0.05);含内容物重、不含内容物重分别增加了23.53%和47.62%,差异极显著(P<0.01);干重增加了16.67%,差异显著(P<0.05)。     

Gastrointestinal volatile fatty acid concentrations and pH in cats

OBJECTIVE: To measure volatile fatty acid (VFA) concentrations and pH in the gastrointestinal tracts of healthy adult cats fed a commercial dry cat food. ANIMALS: 14 cats. PROCEDURE: The gastrointestinal tracts were excised immediately after euthanasia and divided into 6 sections (stomach, duodenum, jejunum, ileum, proximal portion of the colon, and distal portion of the colon). Luminal contents were collected from each segment, pH was measured, and contents were centrifuged. The supernatant was analyzed for acetate, proprionate, butyrate, isobutyrate, valerate, and isovalerate concentrations by use of gas chromatography. RESULTS: Mean total VFA concentrations were lowest in the stomach (20 mmol/L); increased through the duodenum, jejunum, and ileum (30, 29, and 41 mmol/L, respectively); and were greatest in the proximal and distal portions of the colon (109 and 131 mmol/L, respectively). Estimated mean total VFA amounts were low (<600 micromol) throughout all segments of the gastrointestinal tract; pH values increased from the stomach through the ileum and subsequently decreased in the colon. CONCLUSIONS AND CLINICAL RELEVANCE: Total VFA concentrations in the colon were comparable to values reported for the forestomach of ruminants and large intestines of monogastric animals, whereas values in the small intestine were higher than reported for other species. Total VFA amounts were low, consistent with the short, nonvoluminous gastrointestinal tract of carnivores. Luminal pH varied throughout the gastrointestinal tract in a pattern similar to other monogastric animals. Volatile fatty acids probably contribute minimal metabolic energy in cats but may be important in the maintenance of local mucosal health.     

Postoperative ultrasonographic appearance of uncomplicated enterotomy or enterectomy sites in dogs

The ultrasonographic findings in 20 dogs with 25 healing enterotomy and enterectomy sites resulting from the removal of foreign material or correction of intussusceptions are presented. In this prospective study, dogs had preoperative abdominal ultrasound examinations followed by sequential sonographic examinations on the first, third, sixth, and 10th days postenterotomy or enterectomy with an additional sonographic examination after 20 days postoperatively. Documented sonographic features included length and maximal intestinal wall thickness of the enterotomy or enterectomy sites, echogenicity of omental/mesenteric fat, amount of free gas and abdominal effusion, and gastrointestinal motility. Sonographically, 57% of enterotomies and 100% of enterectomies were visualized. Pneumoperitoneum, hyperechoic omental/mesenteric fat, and abdominal effusion did not appreciably hamper evaluation of the intestinal surgical site. Absent wall layering at the surgical site was noted in 96% of dogs at day 1 postoperatively. At the final sonographic examination, wall layering remained altered to absent in 100% of dogs and normal thickness was noted in only 20% of dogs. The median maximal wall thickness was 7 and 8 mm for enterotomies and enterectomies respectively, which occurred between days 1 and 3 and days 3 and 6 postoperatively. Effusion and increased echogenicity of omental/mesenteric fat localized to the surgical site were noted in 42% and 60% of dogs respectively at day 1 postoperatively, with resolution noted between days 3 and 10 postoperatively in 92% and 80% of dogs. Generalized abdominal effusion and pneumoperitoneum were seen in 100% of dogs immediately postoperatively and resolved in 80% by day 10.     

Computed tomographic findings of the gastrointestinal tract in rabbits

BackgroundGastrointestinal (GI) diseases are common in rabbits. Although diagnostic imaging studies can assist clinicians in selecting therapeutic approaches, there are few reports of advanced imaging findings in normal rabbits. Computed tomography (CT) is recognized as a useful tool in dogs and cats, but there are few reports of normal findings on multidetector computed tomography (MDTC) in rabbits. The goals of this study are to describe the CT anatomic imaging appearance of the GI tract and their normal variation in healthy pet rabbits and to obtain the normal wall thickness measurements of normal GI tract structures.MethodsTwenty-three rabbits were scanned under general anesthesia and the CT abdominal images were analyzed by two experienced radiologists. Location and size of the major GI organs and structures were determined, and wall thickness of the stomach, small and large intestines were measured, including the interobserver agreement. Statistical analysis of quantitative and qualitative variables was performed.ResultsWall thickness values were established for the different parts of the stomach (cardia: 3.4 ± 0.4mm; fundus: 1.4 ± 0.2mm; body: 1.4 ± 0.1mm; pylorus: 2.9 ± 0.5mm), small intestines (duodenum: 1.4 ± 0.1mm; jejunum: 1.2 ± 0.1mm; ileum: 1.4 ± 0.1mm), and large intestines (cecum: 1.2 ± 0.1mm; colon ascending: 1.4 ± 0.3 mm and descending: 1.3 ± 0.3mm). When distended the stomach did not extend beyond the caudal limits of the L2 vertebra. The cecum occupied the ventral abdominal region from T12/T13 to L7/S1, the sacculus rotundus was identified in 11 of the 23 rabbits. The sacculus rotundus and vermiform cecal appendix were identified only in rabbits with mild large intestinal distension.Conclusions and clinical relevanceIt was possible to use CT to evaluate the different portions of the GI tract that are not normally readily visible on radiographs and ultrasound (US). Normal wall thickness values of the different portion of the GI tract were stablished. These results provide new and important reference values for CT studies in normal pet rabbits and provide data for further studies in rabbits with GI diseases.