Reduced stomach motility in dogs is not unusual and may lead to retention and vomiting. This condition is usually suspected in dogs with a history of chronic vomiting of stomach contents. Because there may be several underlying causes, it is important to conduct various diagnostic tests to confirm and rule out several disorders. The list of differentials (possible different causes) to confirm or rule out are various. Reduced stomach motility in dogs may arise secondary to a variety of conditions, and once several conditions are ruled out, it is possible to presumptively confirm a primary stomach motility disorder n dogs.
Symptoms of Reduced Stomach Motility in Dogs
When all goes well, a dog's gastric smooth muscles contract allowing the stomach to grind, crush and mix ingested food with digestive juices, reducing it into a liquefied form, that's referred to as "chyme." The food is then pushed down to the rest of the digestive tract where nutrients are absorbed and then the rest is expelled under the form of feces.
First of all, what exactly is motility? "Motility" is a medical term used to describe contraction of the muscles responsible for mixing and propelling food through the gastrointestinal tract (the rhythmic contractions are called peristalsis). Motility is the result of a well-orchestrated event of several complex happenings courtesy of the enteric nervous system and the parasympathetic system with the vagus nerve playing a primary role.
Hormones also play a big role in gastric motility- with gastrin (a hormone that triggers secretion of gastric juice) and cholecystokinin (a hormone secreted by cells in the duodenum which stimulates the release of bile into the intestine) coming into play.
Gastroparesis is the medical term used to depict a disorder where the stomach takes too long to empty its contents. This can happen when nerves or muscles in the digestive tract fail to function with their normal strength and coordination. This can happen for various reasons.
When things go wrong and dogs start developing motility problems, affected dogs may develop the following symptoms:
- Loss of appetite
- Weight loss
- Vomiting undigested dog food
- Abdominal discomfort/pain
Causes of Reduced Stomach Motility in Dogs
[adinserter block="4"]One main cause of reduced stomach motility in dogs is the presence of a blockage in the stomach or intestine due to a foreign item, enlargement of an organ or tissue, or presence of a tumor. The outlet of the stomach (the pylorus and duodenum) is basically obstructed. This mechanical obstruction leads to delayed gastric emptying due to the difficulty of food passing through a tightened passage.
In some cases, reduced stomach motility may be due to defective propulsion. This means that something goes wrong with the force of a dog's gastric smooth muscle contractions. As mentioned, functional stomach motility is the result of a well-orchestrated, coordinated event courtesy of the nervous system, hormones, and chemicals.
Sometimes, the pyloric sphincter found at the exit of the stomach may fail to open enough or at the correct times leading to delayed gastric emptying. The opening of this sphincter is controlled by nerves which are meant to ensure that only very small particles of food leave the stomach. Damage to these nerves may cause problems.
A variety of disorders may interfere with the process including presence of ulcers, infectious or inflammatory diseases (inflammation can alter GI motility) such as inflammatory bowel disease, esophagitis, gastritis or enteritis, enlarged esophagus, stress, electrolyte disturbances and endocrine disorders (diabetes, hypothyroidism). Reduced motility is often seen as a complication following surgery for bloat and associated torsion.
A variety of tests may be needed to get to the source of the problem. These tests may include a complete blood count (CBC), blood chemistry profile, urine test, fecal tests, X-rays, barium contrast study, CPL test for pancreatitis, abdominal ultrasound, test for myasthenia gravis, and an endoscopy, usually as a last test if no causes is found.
Treatment of Reduced Stomach Motility in Dogs
Diet can help some cases of reduced stomach motility in dogs. It is a known fact that liquid foods tend to pass through faster compared to solid foods. Liquids tend to readily pass through in spurts, while solids must be ground down to smaller particles before being pushed out.
It is also known that carbs move through faster compared to protein and protein is expelled much faster than fats, explains Dr. Jean A. Hall, a board-certified veterinarian specializing in internal medicine.
A moist, low protein and low fat diet may therefore be optimal. Cooked pasta or cooked rice may be added. Meals are generally given in frequent, small amounts.
In many cases, reduced stomach motility in dogs requires the use of gastric prokinetic agents. These drugs are meant to speed up the emptying of the stomach by increasing muscle contractions. Examples of these drugs are metoclopramide given 30 to 45 minutes prior to meals and cisapride which is also given about 30 minutes prior to meals. This drug has been shown to be more effective compared to metoclopramide.
Other prokinetic medications include erythromycin, clarithromycin, domperidone, rantidine (Zantac), and nizatidine. Ranitidine may increase the risk of side effects of metoclopramide when given at the same time, explains veterinarian Dr. Chantal Lainesse .