Assessment of gastrointestinal health in racing Alaskan sled dogs using capsule endoscopy and inflammatory cytokines.

OBJECTIVES: Exercise-induced gastrointestinal syndrome occurs in dogs and people and might compromise athlete performance by increasing intestinal permeability and causing gastrointestinal erosions. Racing sled dogs often receive acid suppressant prophylaxis which decreases the incidence of gastric erosions induced by exercise. The objectives were to quantify intestinal injury by measuring serum pro-inflammatory cytokine concentrations before and after exercise and to evaluate gastrointestinal mucosa using video capsule endoscopy after exercise. MATERIALS AND METHODS: Prospective study of 12 racing Alaskan sled dogs receiving approximately 1 mg/kg omeprazole once daily from the day before the race until race completion. Blood was drawn before and 8 to 10 hours after an endurance race for the quantification of cytokines. Gastrointestinal tract mucosa was assessed with video capsule endoscopy immediately post-race. RESULTS: Eight of nine dogs (89%; 95% confidence interval 52 to 100%) had gastric erosions; all dogs (100%, 95% confidence interval 63 to 100%) had small intestinal erosions. Most of the dogs (seven of nine) had straw or foreign material present. Cytokine levels were not different from before to after the race. CLINICAL SIGNIFICANCE: Video capsule endoscopy identified gastrointestinal tract mucosal erosions after exercise in all dogs receiving once-daily omeprazole treatment, though other causes for the lesions besides exercise are possible.

Gastrointestinal angiodysplasias diagnosed using video capsule endoscopy in 15 dogs.

BACKGROUND: Angiodysplasia (AGD) is rarely diagnosed in dogs with gastrointestinal bleeding (GIB) and is reported in case reports in dogs. OBJECTIVE: Describe signalment, clinical and diagnostic features of dogs with gastrointestinal (GI) AGD diagnosed by video capsule endoscopy (VCE). ANIMALS: Dogs with overt or suspected GIB which underwent VCE. METHODS: Dogs for which a VCE was submitted for overt or suspected GIB from 2016 to 2021 were selected retrospectively. Medical records and full-length VCE recordings where AGDs were initially detected, were reviewed by 2 trained internists. AGD was considered definitive if 2 readers detected it. Signalment, clinical signs, blood work, medications, concurrent diseases, findings of previous conventional endoscopy, and surgical exploration (if applicable) of dogs with AGD were recorded. RESULTS: Definitive AGD was diagnosed in 15 of 291 (5%) dogs (12 males, 3 females). Twelve (80%) had overt GIB, 11 (73%) had hematochezia, and 6 (40%) had microcytic and hypochromic anemia. AGD was missed by conventional endoscopy in 9/9 dogs and exploratory surgery in 3/3 dogs. Thirteen capsules were administered by mouth (1 incomplete study), and 2 via endoscopy directly into the duodenum. AGD was visualized in the stomach of 3 dogs, in the small intestine of 4, and in the colon of 13 dogs. CONCLUSION AND CLINICAL IMPORTANCE: Although rare, AGD should be considered in dogs with suspected GIB after a negative conventional endoscopy or surgical exporation. Video capsuel endoscopy appears to be a sensitive test to identify AGD within the GI tract.

Feasibility, complications, and quality of visualization using video capsule endoscopy in 40 dogs with overt or questionable gastrointestinal bleeding.

BACKGROUND: Prospective studies describing video capsule endoscopy (VCE), its feasibility, and complications in dogs are limited. OBJECTIVE: To assess VCE, quality of visualization, complications, and risk factors for incomplete studies in dogs with overt or questionable gastrointestinal bleeding (GIB). ANIMALS: Forty dogs with overt or questionable GIB. METHODS: Prospective, multicenter, interventional study. From August 2017 to March 2020, dogs were examined by VCE (ALICAM) because of overt or questionable GIB. Reported outcomes included diagnostic results of VCE study, quality of visualization, and complications. Risk factors for incomplete studies were evaluated using logistic regression. RESULTS: In total, 40 dogs (13 overt, 27 questionable GIB) were included. The capsules were administered PO in 29 and endoscopically in 11 dogs (6 duodenum, 5 stomach). One capsule was not retrieved. In 24 of 39 recordings, bleeding lesions were identified (10 overt GIB, 14 questionable GIB). Overall, the quality of visualization was poor to limited in the stomach and colon, and adequate to good in the small intestine. The most common complication was an incomplete study in 15/39 studies, particularly after oral administration (13/28). Risk factors for incomplete study after oral administration included administration of simethicone or opioids, chronic enteropathy, and capsule gastric transit time >6 hours. CONCLUSIONS AND CLINICAL IMPORTANCE: Video capsule endoscopy can be used to diagnose a variety of lesions causing bleeding in the gastrointestinal tract of dogs with questionable GIB. Incomplete studies are the most common complications in dogs after oral administration of capsules.

A wireless endoscopy capsule suitable for imaging of the equine stomach and small intestine.

BACKGROUND: Capsule endoscopy offers a new method for visualization of the gastrointestinal mucosa in horses where other imaging technologies have diagnostic limitations. OBJECTIVES: To (1) test the feasibility of using this novel endoscopy capsule to visualize intestinal mucosa in horses, including an objective assessment of image quality, (2) assess how changes in preadministration preparation affect the transit time and the amount of gastrointestinal mucosa visualized, and (3) describe intestinal mucosa lesions in healthy horses. ANIMALS: Five healthy adult horses. METHODS: Three protocols were used in a crossover study design. Protocols varied in time fasted, amount of oral fluid administered, and exercise. Manure was radiographically inspected for capsule recovery. Percentage of visible gastrointestinal mucosa was objectively assessed. RESULTS: Detailed images of the gastrointestinal mucosa were recorded with all 3 protocols, including images of the pylorus, major duodenal papilla, individual villi, and ileocecal junction. Visualization of large intestinal mucosa was poor. Interobserver agreement on image quality was excellent. Capsule administration after feed withholding for 24 hours provided the greatest percentage of visible mucosa in the stomach and small intestine. Total transit time to capsule excretion was 6.5 (3-8.75) days. Of 15 capsules administered, 3 were not recovered. Lesions visualized included mucosal erosion, ulceration and hemorrhage, areas of thickened mucosa, and evidence of parasitism. CONCLUSIONS: This novel endoscopic capsule appears safe, practical, and noninvasive in horses; however, variability in capsule excretion time must be taken into account for clinical application.

Jejunal Lesion Identified at a Previous Anastomosis Site in a Dog Using Capsule Endoscopy.

A 3 yr old spayed female French bulldog was evaluated for a progressive regenerative anemia of unknown origin that was unresponsive to empiric immunosuppressive and gastroprotective therapy. The patient had a history of previous resection and anastomosis of a small intestinal diverticulum ∼2 yr prior to evaluation for her anemia. Capsule endoscopy revealed a focal abnormality in the distal jejunum at the site of a previous bowel resection and anastomosis. This lesion was suspected to be the cause of ongoing gastrointestinal bleeding and anemia. Exploratory laparotomy combined with endoscopy was performed to further investigate and localize the jejunal lesion. The lesion was resected, and a primary end-to-end jejunal anastomosis was performed. Histopathology of the specimen revealed jejunal suture granulomas with focal ulceration. The patient recovered well from surgery with significant improvement of the anemia and resolution of clinical signs at recheck examinations 1 and 2 wk postoperatively. Complete resolution of the anemia was noted at a 6 wk follow-up. The case report demonstrates how, in cases of unknown causes of anemia, capsule endoscopy is a noninvasive method of identifying the presence of gastrointestinal bleeding as a result of lesions that might otherwise not be detectable with abdominal ultrasound or conventional endoscopy. The report also documents a long-term complication to a resection and anastomosis surgery.

Use of video capsule endoscopy to identify gastrointestinal lesions in dogs with microcytosis or gastrointestinal hemorrhage.

BACKGROUND: Video capsule endoscopy (VCE) is a noninvasive imaging modality that can identify mucosal lesions not detected with traditional endoscopy or abdominal sonography. In people, VCE is used in diagnostic and management protocols of various gastrointestinal (GI) disorders, particularly in GI bleeding of obscure origin or unexplained iron deficiency anemia (IDA). OBJECTIVE: To evaluate the utility of VCE in the identification of mucosal lesions in dogs with evidence of GI hemorrhage. ANIMALS: Sixteen client-owned dogs that underwent VCE. METHODS: Retrospective case-control study. Medical records were reviewed to include dogs with microcytosis, low normal mean corpuscular volume, or clinical GI bleeding that received VCE. RESULTS: Median age of dogs was 8.7 years (range, 8 months to 15 years) with a median weight of 21.7 kg (range, 6.9-62.5 kg). Abdominal ultrasound (16), abdominal radiography (4), and abdominal CT (1) did not identify a cause for GI blood loss. Gastric mucosal lesions were identified by VCE in 15 of 16 dogs and small intestinal lesions in 12 of 14 dogs, with 2 capsules remaining in the stomach. Endoscopy was performed in 2 dogs before VCE; 1 dog had additional small intestinal lesions identified through the use of VCE. CONCLUSIONS AND CLINICAL IMPORTANCE: Video capsule endoscopy is a minimally invasive diagnostic tool that can identify GI lesions in dogs presenting with microcytosis with or without GI hemorrhage when ultrasonography is inconclusive; however, the majority of lesions identified would have been apparent with conventional endoscopy.

Is there an application for wireless capsule endoscopy in horses?

This pilot study assessed wireless capsule endoscopy in horses. Image transmission was achieved with good image quality. Time to exit the stomach was variable and identified as one limitation, together with gaps in image transmission, capsule tumbling, and inability to accurately locate the capsule. Findings demonstrate usefulness and current limitations.

Existe-t-il une application pour l'endoscopie par capsule sans fil chez les chevaux? Cette étude pilote a évalué l'endoscopie par capsule chez les chevaux. La transmission d'images a permis d'obtenir une bonne qualité d'image. Le temps jusqu'à la sortie de l'estomac était variable et identifié comme une limitation, de même que les lacunes dans la transmission de l'image, le culbutage de la capsule et l'incapacité de situer l'emplacement exact de la capsule. Les résultats démontrent l'utilité et les limitations actuelles.(Traduit par Isabelle Vallières).

Effect of hospitalization on gastrointestinal motility and pH in dogs.

OBJECTIVE To determine the effect of hospitalization on gastrointestinal motility and pH in healthy dogs. DESIGN Experimental study. ANIMALS 12 healthy adult dogs. PROCEDURES A wireless motility capsule (WMC) that measured pressure, transit time, and pH within the gastrointestinal tract was administered orally to dogs in 2 phases. In the first phase, dogs received the WMC at the hospital and then returned to their home to follow their daily routine. In the second phase, dogs were hospitalized, housed individually, had abdominal radiography performed daily, and were leash exercised 4 to 6 times/d until the WMC passed in the feces. All dogs received the same diet twice per day in both phases. Data were compared between phases with the Wilcoxon signed rank test. RESULTS Data were collected from 11 dogs; 1 dog was excluded because the WMC failed to exit the stomach. Median gastric emptying time during hospitalization (71.8 hours; range, 10.7 to 163.0 hours) was significantly longer than at home (17.6 hours; range, 9.7 to 80.8 hours). Values of all other gastric, small bowel, and large bowel parameters (motility index, motility pattern, pH, and transit time) were similar between phases. No change in gastric pH was detected over the hospitalization period. High interdog variability was evident for all measured parameters. CONCLUSIONS AND CLINICAL RELEVANCE Hospitalization of dogs may result in a prolonged gastric emptying time, which could adversely affect gastric emptying of meals, transit of orally administered drugs, or assessments of underlying motility disorders.

Evaluation of capsule endoscopy to detect mucosal lesions associated with gastrointestinal bleeding in dogs.

OBJECTIVE: The objective of this study was to examine the utility of capsule endoscopy to detect mucosal abnormalities in dogs with gastrointestinal haemorrhage. METHODS: Capsules were administered to 2 healthy controls and 8 patients with gastrointestinal haemorrhage. Images were evaluated for quality, gastric emptying time, small intestinal transit time and presence of lesions. RESULTS: There were no adverse effects of capsule endoscopy in dogs weighing from 7·7 to 58 kg. The capsule traversed the entire gastrointestinal tract in 5 of 8 patients, with high quality images obtained in the stomach and small intestine. Gastric emptying time and small intestinal transit time ranged from 1 to 270 and 15 to 180 minutes, respectively. In 3 of 8 patients, the capsule remained in the stomach despite pro-kinetics. Gastric lesions included mild haemorrhage and pinpoint erosion (4 of 8), a mass (1) and thickened bleeding pyloric mucosa (2). Two of 3 dogs with capsule retention had gastric lesions. Intestinal lesions included a healing duodenal ulcer, abnormal villi, ileal ulceration and colonic bleeding. Lesions identified by capsule endoscopy were considered a significant source of haemorrhage in 4 of 7 dogs with active bleeding. The relevance of pinpoint gastric mucosal erosions to blood loss is unclear. CLINICAL SIGNIFICANCE: Capsule endoscopy can enable the non-invasive detection of gastric and small intestinal mucosal lesions in dogs presenting for evaluation of gastrointestinal bleeding.

Determination of anthelmintic efficacy against Toxocara canis in dogs by use of capsule endoscopy.

Industry guidelines for anthelmintic testing call for postmortem inspection of animals to verify treatment efficacy. A previous study showed that capsule endoscopy (CE) can be performed on dogs in vivo to quantify hookworms in the small intestine. Adoption of a minimally invasive procedure such as this could reduce the need for necropsy in efficacy trials. The present study employed CE to enumerate Toxocara canis in dogs, with two main goals: to determine if multiple capsule examinations improves the accuracy of worm counts compared to a single examination, and to establish if the efficacy of an anthelmintic compound is the same whether calculated using CE or necropsy data. To avoid needless animal sacrifice, the study was carried out on beagle dogs already in a product development trial with a planned terminal endpoint. Dogs were infected by oral inoculation with T. canis eggs. Untreated control dogs (n=8) were evaluated by CE three times while dogs treated with test compounds (3 groups of 4) were examined only once. Utilizing either the average count or just the last complete capsule examination, a robust correlation was found between CE and postmortem numbers (r=0.94, p<0.001). Calculated anthelmintic efficacy was essentially identical for the two enumeration methods, ranging from 94% to 100% for the three research compounds. CE may therefore be a viable alternative to necropsy for T. canis parasiticide trials.

Wireless ambulatory esophageal pH monitoring in dogs with clinical signs interpreted as gastroesophageal reflux.

BACKGROUND: Although gastroesophageal reflux (GER) often is assumed to be causative for upper gastrointestinal and respiratory signs in dogs, no attempts have been made to verify this assumption. OBJECTIVES: To monitor esophageal pH with the Bravo pH system in healthy dogs and client-owned dogs displaying signs commonly attributed to GER. ANIMALS: Seven healthy and 22 client-owned dogs. METHODS: After routine esophagogastroduodenoscopy, radiotelemetric pH capsules were placed in distal esophagus for continuous pH recording. Reflux was defined as single pH measurement <4. At discharge, owners were instructed to press individually predefined clinical sign-buttons on the receiver whenever indicated. Results between groups were compared using Mann-Whitney U-test. RESULTS: The median (range) number of refluxes in client-owned and healthy dogs, respectively, was 17 (1-205) and 10 (1-65), the number of refluxes >5 minutes in duration was 1 (0-14), and 1 (0-4), duration of longest reflux (min) was 10 (0-65) and 8 (0-27), and fractional time pH <4 (%) was 0.76% (0.01-6.28), and 0.3% (0-3.1). No differences were found between groups. The median of 7 (1-35) clinical sign-button pushes were recorded in 21 dogs. Median of 12.5% (2.8% [1/35]-50% [2/4]) reflux-positive clinical sign-button pushes was found in 10 dogs with reflux-positive pushes. Five (22.7%) dogs had increased esophageal acid exposure, and mild esophagitis was noted in 1 dog. CONCLUSION AND CLINICAL IMPORTANCE: Despite evidence of increased GER in some dogs, the clinical sign-reflux association remained poor. Future investigation should focus on dogs with esophagitis.

The effect of macrogol administration on the quality of macroscopic images and transit time in canine capsule endoscopy.

The present experiment evaluated the quality of macroscopic images and the mean time of capsule passage through different sections of the gastrointestinal tract in dogs subjected to different preparation protocols before capsule endoscopy. In the first examination, the colonoscopy prepara- tion protocol was applied, and in the second examination, the animals were administered macrogol. The study revealed that macrogol administration before capsule endoscopy significantly improved the quality of macroscopic images. The colonoscopy preparation protocol may not support accurate visualization of the large bowel mucosa and, in selected patients, also the small bowel mucosa. Macrogol administration had no effect on capsule transit time through the alimentary canal. Capsules used in endoscopic evaluations of the small bowel in humans may have limited applications in macro- scopic examinations of large bowel mucosa in dogs.

Utility of capsule endoscopy for evaluating anthelmintic efficacy in fully conscious dogs.

The current accepted standard for evaluating the efficacy of gastrointestinal anthelmintic drugs is necropsy of infected animals followed by a comparison of worm counts between treated and non-treated groups. In this study capsule endoscopy, a minimally invasive method of imaging the small intestine of humans, is evaluated as a possible alternative to necropsy for the purposes of worm quantification in dogs. Eighteen Beagle dogs were included in this study. These dogs were part of a separate trial intended to determine the efficacy of various candidate parasiticides against Ancylostoma caninum via the necropsy standard. Dogs were inoculated with A. caninum L3s 4 weeks prior to treatment with one of the candidate compounds; a control group (n=8) received no treatment. Capsule endoscopy was performed 6-14 days post-treatment, followed by necropsy the following day. Seventeen dogs had complete examinations, i.e. the capsule traversed the small intestine and reached the colon within the battery life of the capsule. A strong correlation (r(s)=0.87, P<0.0001) was observed between the worm counts acquired by capsule endoscopy and necropsy. There was no clear relationship between the ability of the capsule endoscope to detect hookworms and either visibility of the intestinal lumen or small intestinal transit time. Generation of a virtual spatial record of hookworm location from the capsule endoscopy data revealed a temporal trend, with the majority of worms present in the proximal small intestine in the morning versus the central to distal small intestine in the afternoon. Worm distribution as determined by capsule endoscopy closely resembled post-mortem findings. In conclusion, capsule endoscopy shows promise as an alternative to necropsy for the enumeration of A. caninum in the canine small intestine, although further work is required to improve completion rates and optimise intestinal examination.

Assessment of the relationship between body weight and gastrointestinal transit times measured by use of a wireless motility capsule system in dogs.

OBJECTIVE: To assess the relationship between body weight and gastrointestinal transit times measured by use of a wireless motility capsule (WMC) system in healthy dogs. ANIMALS: 31 healthy adult dogs that weighed between 19.6 and 81.2 kg. PROCEDURES: Food was withheld overnight. The following morning, a WMC was orally administered to each dog, and each dog was then fed a test meal that provided a fourth of the daily energy requirements. A vest was fitted on each dog to hold a receiver that collected and stored data from the WMC. Measurements were obtained with each dog in its home environment. Regression analysis was used to assess the relationship between body weight and gastrointestinal transit times. RESULTS: Gastric emptying time (GET) ranged from 405 to 897 minutes, small bowel transit time (SBTT) ranged from 96 to 224 minutes, large bowel transit time (LBTT) ranged from 427 to 2,573 minutes, and total transit time (TTT) ranged from 1,294 to 3,443 minutes. There was no positive relationship between body weight and gastrointestinal transit times. A nonlinear inverse relationship between body weight and GET and between body weight and SBTT best fit the data. The LBTT could not be explained by this model and likely influenced the poor fit for the TTT. CONCLUSIONS AND CLINICAL RELEVANCE: A positive relationship did not exist between body weight and gastrointestinal transit times. Dogs with the lowest body weight of the cohort appeared to have longer gastric and small intestinal transit times than did large- and giant-breed dogs.

Variability associated with repeated measurements of gastrointestinal tract motility in dogs obtained by use of a wireless motility capsule system and scintigraphy.

OBJECTIVE: To compare repeatability of measurements of gastrointestinal tract motility in healthy dogs obtained by use of a wireless motility capsule (WMC) and scintigraphy. ANIMALS: 6 healthy adult dogs (mean +/- SD body weight, 21.5 +/- 1.8 kg). PROCEDURES: A radiolabeled test meal was offered immediately after oral administration of a WMC. Serial static scintigraphic abdominal images were acquired for 270 minutes. A dedicated remote receiver was used for data collection from the WMC until the WMC was expelled in the feces. Each dog was evaluated 3 times at intervals of 1 to 2 weeks. RESULTS: Mean gastric emptying half-time measured by use of scintigraphy (T(1/2)-GES) for each dog ranged from 99.9 to 181.2 minutes. Mean gastric emptying time (GET) measured by use of the WMC (GET-WMC) in each dog ranged from 385.3 to 669.7 minutes. Mean coefficient of variation was 11.8% for T(1/2)-GES and 7.8% for GET-WMC. The intraclass correlation coefficient was 69% for T(1/2)-GES and 71% for GET-WMC. Results for a nested analysis of covariance suggested that both methods were comparable for the evaluation of gastric emptying. CONCLUSIONS AND CLINICAL RELEVANCE: Scintigraphy and a WMC system had similar variation for assessment of gastric emptying. Moderate intraindividual variability was detected for both methods and must be considered when interpreting test results for individual dogs. Repeatability of measurements obtained by use of the WMC was equivalent to that obtained by use of scintigraphy. The WMC system offers a nonradioactive, user-friendly method for assessment of gastric emptying in dogs.

Preliminary study of capsule endoscopy in the small intestine of horses.

OBJECTIVE: To evaluate the visibility of various portions of the small intestine in healthy horses using capsule endoscopy. PROCEDURE: Six healthy, conscious adult Thoroughbreds were restrained and an endoscopic capsule (PillCam SB capsule) was inserted into the oesophagus using an intranasal catheter aided by a guide wire. Water (500 mL) flushed the capsule down the gastrointestinal tract. Data were collected and stored in the recorder of the endoscopic system for 6 hours after capsule insertion and the images were evaluated using an image reader and scored using a visual analogue scale. RESULTS: Capsule endoscopy enabled observation of the distinct mucosal shape, colour, and villus structure of the intestinal lumen from the duodenum through the proximal jejunum. At 4 h after passing the pylorus, the endoscopic capsule started transmitting increasingly dark images in the distal jejunum as the lumen circumference increased. Means of the visual analogue scale in the duodenum, proximal jejunum, and distal jejunum were 93.8 +/- 1.3%, 86.2 +/- 2.5% and 48.8 +/- 6.3%, respectively. Differences among these values were statistically significant (P < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Capsule endoscopy enables observation of the distinct mucosal shape, colour and villus structure of the proximal and mid-small intestine in healthy horses.