Tube gastrostomy in dogs

Tube gastrostomy was performed in 19 dogs over a period of 36 months. Indications for tube gastrostomy included non-oral feeding for the management of oesophageal injuries (nine cases) and dysphagia resulting from oral or pharyngeal trauma (two cases) and decompression and, or, gastropexy for gastric diseases including gastric dilatation volvulus (four cases), gastric outflow diseases (three cases) and gastric neoplasia (one case). All the tubes were placed surgically and left in situ for periods of up to 14 days. Feeding was by frequent bolus administration of a proprietary enteral food initially followed by homogenised commercial dog food. The tubes were readily managed and patency maintained in all cases. Gastric stomata granulated within three days of tube removal. Fourteen dogs recovered and returned to normal oral feeding while three died as the result of their presenting condition. A fourth was euthanased four months after surgery because of recurrence of a gastric malignancy. This review indicates that surgically placed tube gastrostomy is readily performed and is an effective means of providing non-oral alimentation and, or, gastric decompression.     

Multiple polyps of the gastric mucosa in two dogs

Multiple polyps of the gastric mucosa are described in a 6-year-old male Airedale and a 6-year-old male French Bulldog. The first dog suffered from chronic vomiting while the second vomited for only 5 days and exhibited signs of pyloric stenosis. Gastroscopic examination revealed broad, thick rolls in the Airedale's antral mucosa and radiographically the antral wall was rigid and normal peristalsis was absent. Radiographic examination of the French Bulldog revealed pyloric stenosis without passage of contrast material through the pyloric canal.
In biopsy specimens from the Airedale there were long thin foveolae and slight cellular infiltrations. Multiple polyps of the gastric mucosa were found throughout the antrum at necropsy. The resected antrum of the French Bulldog had a villous growth pattern with adenomatous formations and inflammation.     

Evaluation of the effect of ranitidine on gastroduodenal contractile activity and gastric emptying in horses

Objective-To determine the effect of ranitidine on gastric emptying in horses. Animals-11 adult horses. Procedures-In vitro, isolated muscle strips from the pyloric antrum and duodenum of 5 horses were suspended in baths and attached to isometric force transducers. Once stable spontaneous contractions were observed, ranitidine or diluent was added at cumulative increasing concentrations. Isometric stress responses were compared. In vivo, 6 horses were assigned to a group in a prospective randomized crossover study design with a wash-out period of 2 weeks between trials. Ranitidine (2.2 mg/kg) or saline (0.9% NaCl) solution was administered IV, and 15 minutes later, acetaminophen (20 mg/kg), diluted in 400 mL of water, was administered via nasogastric tube to evaluate the liquid phase of gastric emptying. Serum acetaminophen concentration was measured at several time points for 3 hours by use of liquid chromatography tandem mass spectrometry. Frequency of defecation was recorded during the 3 hours of the study. Results-Ranitidine increased the contractile activity of the pyloric antrum smooth muscle at a concentration of 10(4) M. No significant effect of ranitidine on plasma kinetics of acetaminophen was identified. Frequency of defecation did not differ between groups. Conclusions and Clinical Relevance-Ranitidine did increase gastric motility in vitro, but no effect on liquid phase gastric emptying was identified in healthy horses by use of the acetaminophen absorption model. Results do not support the use of ranitidine to promote gastric emptying.     

ULTRASONOGRAPHIC APPEARANCE OF CANINE GASTRIC POLYPS

Benign gastric polyps are uncommon in dogs and most are discovered incidentally. Polyps protruding into the pyloric antrum can cause gastric outflow obstruction. Clinical and ultrasonographic findings in seven dogs with histologically confirmed benign mucosal gastric polyps were reviewed. Sonographic findings such as shape, size, echogenicity, location, evidence of gastric wall thickening, wall layering, and size of regional lymph nodes were recorded. Five sessile and two pedunculated masses of different sizes (range 7–60 mm) and echogenicities were found. They primarily arose from the mucosal layer and protruded into the gastric lumen. Only one dog had a large inhomogeneous mass with a poorly visualized gastric wall layering. The polyps were all single, and were located in the pyloric antrum in six out of seven dogs. Although the ultrasonographic appearance allowed a presumptive diagnosis of mucosal gastric polyp, the final diagnosis was determined from histopathologic examination.     

Surgical treatment of gastric leiomyoma in a dog

A 12-year-old entire male Maltese terrier was presented with a 1 month history of vomiting and haematemesis. Microcytic hypochromic anaemia was detected. Abdominal radiography, ultrasonography and gastric endoscopy identified a discrete intramural mass in the pyloric antrum. An ulcerated leiomyoma was removed by a partial-thickness intraluminal resection of the gastric wall. The dog recovered well and is free from clinical signs 20 months after surgery.     

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.     

SPONTANEOUS PNEUMOPERITONEUM SUBSEQUENT TO GASTRIC VOLVULUS IN TWO DOGS

In two dogs spontaneous pneumoperitoneum developed following gastric volvulus. The pneumoperitoneum resulted from splenic necrosis and Klebsiella pneumoniae peritonitis in one and from a gastric perforation near the gastroesophageal junction in the other. The first dog was successfully treated by splenectomy, abdominal lavage, and systemic antibiotic therapy; the other was treated by closure of the perforation, tube gastrostomy, abdominal lavage, and systemic antibiotic therapy. One dog was euthanized four weeks after surgery because of metastatic cancer, and the other was euthanized six weeks after surgery due to recurrence of abdominal distention and peritonitis.     

Gastropexy with an automatic stapling instrument for the treatment of gastric dilatation and volvulus in 20 dogs

Surgical stapling equipment was used to create a gastropexy in 20 dogs undergoing emergency surgery for gastric dilatation and volvulus (GDV). The technique involved creation of a tunnel between the seromuscular layer and the submucosa of the pyloric antrum, and a matching tunnel beneath the right m. transversus abdominis. The arms of a gastrointestinal anastomosis stapling device were introduced into the tunnels, and the device was fired to create the gastropexy. One dog died of systemic sequelae of GDV during the early postoperative period. None of the remaining 19 dogs developed a recurrence of GDV during follow-up periods ranging from 5 to 43 months. In 11 dogs, the integrity of the gastropexy was evaluated by abdominal ultrasonography and either negative contrast gastrography or double contrast gastrography; in these dogs, the radiographic and/or the ultrasonographic findings were suggestive of an intact gastropexy. There were no complications involving the gastropexy staple line. The results of this study indicate that an effective and consistent permanent gastropexy can be created, using surgical stapling equipment.     

GASTROGASTRIC INTUSSUSCEPTION IN A DOG

A three-year-old, intact male, Rottweiler is presented with a gastrogastric intussusception. This is one of only two known reports of gastrogastric intussusception in the dog. Lateral and ventrodorsal radiographs and ultrasound revealed a gastric mass, however the diagnosis of gastrogastric intussusception was made during surgery. The patient in this report had no associated tumor and the pyloric antrum was the intussusceptum. Cause of the intussusception is unknown.     

A case of canine gastrinoma

The dog of this case was a 10-year-old Shih Tzu with refractory vomiting, diarrhea and anorexia. Endoscopy revealed an unclear at gastric angle, a stenosis at pyloric antrum and congestion in duodenal mucosa. Since abnormal shadows of irregular echo-levels were disclosed by pancreas ultrasonography, serum gastrin level was determined with a suspect of gastrinoma. And an increase of serum gastrin was demonstrated. In addition, postmortem histological examination revealed that the pancreatic cells were positive for gastrin. Based on these findings, the dog was diagnosed as pancreatic gastrinoma.     

Congenital pyloric mucosal fold resulting in an antral valve outflow obstruction in a bull terrier

An under‐sized three‐month‐old female bull terrier was referred with a history of regurgitation since three days of age. Thoracic radiographs were unremarkable, while abdominal radiographs showed a distended stomach, despite a 12 hour fast. Abdominal ultrasonography revealed gastric outflow obstruction of unclear aetiology. Coeliotomy was performed, during which an excessive mucosal fold at the pyloric antrum was excised. Histopathology of the pyloric fold revealed mild oedema and fibrosis of the mucosal tissue. The dog made a complete recovery, with resolution of regurgitation and grew to within the expected breed size. In the authors’ opinion, this is the first canine report of congenital antral mucosal valve resulting in gastric outflow obstruction, and only the second report in any species.     

Metoclopramide Reversal of Decreased Gastrointestinal Myoelectric and Contractile Activity in a Model of Canine Postoperative Ileus

Postoperative ileus is characterized by decreased gastrointestinal myoelectric activity and motility. Metoclopramide was used to treat experimentally induced postoperative ileus in six dogs. Contractile activity was monitored by extraluminal strain gages on the pyloric antrum and proximal segment of the duodenum, and myoelectric activity was measured by recording bipolar electromyograms (EMGs) at the pyloric antrum, pyloric canal, proximal segment of the duodenum, proximal and distal parts of the jejunum, and ileum. Measurements were obtained from animals without ileus (baseline) and those with ileus that were either untreated or treated with metoclopramide. Adynamic ileus was induced by rubbing a 50 cm segment of jejunum with a dry sponge for 5 minutes and exposing the bowel to the air for 30 minutes. Treated dogs received metoclopramide (0.4 mg/kg 4 times daily [QID] intravenously [IV]), whereas untreated dogs received a saline placebo, starting 1 hour after celiotomy closure. Recordings were made for 26 hours after induction of ileus. The phases of the migrating myoelectric complex (MMC) were identified and motility index values were determined. During ileus, the MMC phase II duration was increased at the duodenum and phase III duration was decreased at the antrum, pylorus, duodenum, and proximal segment of the jejunum (p less than 0.05). Motility index values were decreased at the antrum and duodenum during ileus (p less than 0.05). Treatment with metoclopramide reversed the MMC phase III inhibition at the antrum and pylorus, and partially reversed the inhibition at the duodenum and jejunum (p less than 0.05). Motility index values were restored to preoperative baseline values with metoclopramide treatment (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Heineke–Mikulicz pyloroplasty for the treatment of pyloric stenosis secondary to gastro-duodenal ulcer disease in three foals

The objective of the study was to describe a modified Heineke–Mikulicz pyloroplasty for the treatment of pyloric stenosis in foals due to gastric ulceration and assess the short- and long-term outcome of foals receiving the pyloroplasty. Medical records of foals undergoing a modified Heineke–Mikulicz pyloroplasty due to gastric outflow obstruction secondary to a pyloric stenosis were included in this retrospective case series. The pyloroplasty consisted of an oral to aboral full thickness longitudinal incision on the ventral aspect of the pylorus and proximal duodenum, which was sutured closed with 0 polydioxanone in a transverse orientation, thereby, enlarging the pyloric lumen diameter. Long-term outcome was obtained from medical and race records. The pyloroplasty was successfully performed in three foals with a surgical time of 95–121 min, with immediate return to nursing and hospital stay of 4–14 days. Complications included a small intestinal volvulus and intra-abdominal adhesions in a foal that did not survive. Another foal had an incisional infection. Two of the three foals went on to race. It was concluded that the pyloroplasty procedure is an acceptable option for the treatment of pyloric stenosis and secondary gastric outflow obstruction due to gastric ulceration. The limited amount of bowel manipulation with no change in intestinal flow, along with the successful outcomes achieved, make this another surgical option available for the correction of pyloric stenosis in foals.     

Surgical Treatment of Gastric Outflow Obstruction in 40 Foals

Objective— To report short- and long-term survival and factors affecting outcome of foals after surgical correction of gastric outflow obstruction.
Study Design— Case series.
Animals— Foals (n=40) aged 5–180 days.
Methods— Clinical signs, laboratory data, diagnostic imaging, surgical findings, surgical procedures, medical treatment, and necropsy findings were retrieved from medical records. Outcome was obtained by reviewing performance, sales, and produce records or by telephone conversations with the owners.
Results— Gastric outflow obstruction was treated by gastroduodenostomy or by gastrojejunostomy with or without jejunojejunostomy. Long-term follow-up was available for 36 of 39 foals that survived to hospital discharge; 25 (69%) survived >2 years. All 8 foals with pyloric obstruction survived >2 years, whereas only 11 of 21 (52%) foals with duodenal obstruction survived >2 years. Six of 8 foals with obstruction of the duodenum and pylorus survived >2 years. Obstruction of the duodenum, adhesions to the duodenum, and postoperative ileus were significantly associated with decreased long-term survival.
Conclusions— Long-term outcome after gastric bypass procedures was substantially improved compared with previous reports. Factors that may have contributed to improved survival include better case selection and performing the gastrojejunostomy with the jejunum aligned from left to right.
Clinical Relevance— The prognosis for long-term survival after surgical bypass of pyloric obstruction is excellent. The overall prognosis for long-term survival after surgical bypass of duodenal obstruction is fair but should be considered guarded in those with pre-existing duodenal adhesions.     

Aortic thromboembolism as a complication of gastric dilatation/volvulus in a dog

An unusual complication of gastric dilatation/volvulus developed in a 10-year-old spayed Great Dane. An aortic thromboembolus lodged in the iliac artery bifurcation 4 days after admission and tube gastropexy to correct the condition. The dog was euthanatized after 48 hours of supportive care failed to elicit any improvement. Thrombus formation appeared to originate in the left ventricle; however, a primary cause could not be determined.     

Operative techniques and recurrence rates associated with gastric volvulus in the dog

Numerous surgical procedures have been attempted to correct the immediate emergency associated with the gastric dilation-volvulus syndrome in the dog. These surgical procedures included anatomical repositioning alone, gastropexy, gastrotomy with an occasional partial gastrectomy, pyloric surgery, pharyngostomy tube, and splenectomy. None of these procedures has been shown to totally prevent recurrence of gastric volvulus.     

Ultrasonographic and surgical findings of a gastric hyperplastic polyp resulting in pyloric obstruction in an 11-week-old French Bulldog

An 11-week-old male entire French Bulldog was presented with a 3-week history of projectile vomiting after eating that was unresponsive to medical therapy. Ultrasonographic examination revealed a 1 × 2 cm pedunculated polypoid mass in the pyloric antrum. Histopathology showed this to be comprised of a pedunculated hyperplastic proliferation of gastric mucosal epithelium and submucosa, with dilatation of the glandular pits and a moderate degree of submucosal fibrosis and small amount of smooth muscle hyperplasia in the submucosa. The tunica muscularis was not involved in the polyp and appeared to be of normal thickness. Surgical treatment by pylorectomy and end-to-end gastroduodenostomy (Billroth I) was successful.     

EVALUATION OF THE GASTROINTESTINAL TRACT IN DOGS USING COMPUTED TOMOGRAPHY

Abdominal computed tomography (CT) studies of 19 dogs with no history or clinical signs of gastrointestinal disease, and two dogs with a histological diagnosis of gastrointestinal neoplasia were examined retrospectively. Gastrointestinal segments were evaluated subjectively for conspicuity, contrast enhancement, and wall layering after contrast medium administration. In dogs without gastrointestinal disease, there were 62.8% of gastrointestinal segments (serosa to serosa) and 77.7% of gastrointestinal walls (serosa to mucosa) visualized. Wall layering on postcontrast images was seen in 21.8% of gastrointestinal segments. There was significant association between gastrointestinal diameter and wall thickness. There was significant association between weight and gastrointestinal wall thickness in the following regions: gastric fundus, gastric body, gastric pylorus, gastric pyloric antrum, duodenal cranial flexure, jejunum and ascending colon, and between patient weight and gastrointestinal diameter in cranial duodenal flexure, descending duodenum, transverse duodenum, ascending duodenum, and jejunum. Measurements acquired from CT studies correlated well with previously published normal reference ranges for radiographic and ultrasonographic studies. Gastrointestinal neoplasia, diagnosed in two dogs, had a gastrointestinal wall thickness greater than the range of the dogs without gastrointestinal disease. Computed tomography offers identification of the gastrointestinal tract segments in dogs, allows for evaluation of gastrointestinal diameter and aids in investigation of gastrointestinal wall thickness.     

Pylorogastric intussusception in the dog: a case report and literature review

A 10-month-old, neutered male Saint Bernard presented for evaluation of acute, severe vomiting. A soft-tissue mass was noted within the stomach on survey abdominal radiographs. The diagnosis of pylorogastric intussusception was made during exploratory celiotomy. The intussusception was manually reduced at surgery, the pyloric antrum was enlarged, and the duodenum was permanently affixed to the abdominal wall in an attempt to prevent recurrence of the intussusception. The dog recovered, has gained weight (5 kg), and has had only one isolated episode of vomiting during the one year since discharge from the hospital. This report documents the fourth reported case of pylorogastric (i.e., duodenogastric, gastrogastric) intussusception in the veterinary literature and is the first report that details the surgical management of the disease.     

The effects of medetomidine and xylazine on gastrointestinal motility and gastrin release in the dog

The effect of medetomidine, a potent and highly selective α₂-adrenoceptor agonist, on the motility of the gastric antrum, duodenum, mid-jejunum and ileum was investigated in ten dogs. Its effect on the release of gastrin was also determined. Administration of medetomidine intramuscularly (i.m.) at a dose of 40 μg/kg inhibited the motility of the gastric antrum, duodenum, mid-jejunum and ileum significantly, in comparison to administration of xylazine intramuscularly at a dose of 2.0 mg/kg. The release of gastrin was also significantly decreased in dogs receiving medetomidine. It was found to inhibit the motility in the gastric antrum and duodenum longer than in the mid-jejunum and ileum, presumably by acting specifically on α₂-adrenoceptors, likely at the peripheral level. Medetomidine also inhibited the gastric contraction associated with gastrin secretion.