A dog’s stomach, a vital component of its digestive system, is located in the anterior portion of the abdomen, primarily on the left side, tucked just behind the rib cage. Its position is more flexible than in humans, allowing for greater expansion, especially important given a dog’s tendency to gulp down large meals quickly.
More specifically, the stomach sits caudal (towards the tail) to the liver and diaphragm, the muscular sheet that separates the chest cavity from the abdominal cavity. It’s bordered cranially (towards the head) by the esophagus, which delivers food from the mouth, and caudally by the duodenum, the first part of the small intestine. The spleen, an organ involved in blood filtration and immune function, often lies close to the stomach, nestled along its greater curvature.
The stomach’s shape can change depending on its contents. When empty, it’s contracted. After a large meal, it expands significantly, sometimes even extending across the midline to the right side of the abdomen. This elasticity is crucial, allowing dogs to consume and process varying quantities of food at once.
Internally, the stomach is lined with a mucous membrane containing numerous folds called rugae. These rugae increase the surface area, aiding in the mixing and churning of food with gastric juices. The gastric juices, secreted by specialized cells in the stomach lining, contain hydrochloric acid and enzymes like pepsin, which break down proteins. The mucous coating protects the stomach lining from being digested by its own acidic secretions.
The entrance to the stomach from the esophagus is controlled by the cardiac sphincter, a muscular ring that prevents stomach contents from flowing back into the esophagus. The exit of the stomach, leading into the duodenum, is controlled by the pyloric sphincter. This sphincter regulates the passage of partially digested food, called chyme, into the small intestine in controlled amounts. Proper function of these sphincters is essential for efficient digestion and preventing issues like acid reflux or delayed gastric emptying.
The location of the stomach makes it susceptible to certain health problems. Gastric dilatation-volvulus (GDV), or bloat, is a life-threatening condition where the stomach fills with gas and then twists, cutting off blood supply. Deep-chested breeds are particularly prone to GDV. Similarly, the proximity to other organs like the spleen and liver means that diseases affecting those organs can sometimes impact the stomach, and vice-versa.
Palpation of the abdomen can sometimes allow a veterinarian to feel the stomach, especially if it’s distended. Radiographs (X-rays) and ultrasound are commonly used to visualize the stomach and assess its size, shape, and contents, as well as to detect any abnormalities. Endoscopy, where a small camera is inserted into the stomach, can provide a direct view of the stomach lining and allow for biopsies if needed.
Leave a Reply