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Narrowing of Pyloric Canal in Dogs

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Chronic Hypertrophic Pyloric Gastropathy in Dogs


Chronic hypertrophic pyloric gastropathy, or pyloric stenosis, or, is the narrowing of the pyloric canal due to an overgrowth of muscles of the region. This region of the stomach connects with the first part of the small intestine called the duodenum. The exact cause of the disease is still unknown, but it has been found to be either congenital (existing at birth) in nature or acquired later in life.


Cases of congenital hypertrophic pyloric stenosis is found to be common in the boxer, Boston terrier, and bulldog. The acquired disease, on the othe hand, is more common in the Lhasa apso, shih tzu, Pekingese, and poodle. Males are also more predisposed to this disease than females.


Symptoms and Types


The severity of symptoms directly correlates to the extent of the pyloric canal's narrowing; these include chronic, intermittent vomiting (often several hours after eating), loss of appetite, and weight loss. Vomiting may contain undigested or partially digested food, and does not settle with the administration of drugs.



The exact cause for chronic hypertrophic pyloric gastropathy is still unknown, though it is believed to be either congenital (existing at birth) or acquired later in life. Risk factors that may play a role in influencing the disease process include:


  • Tumors
  • Chronic stress
  • Chronic gastritis
  • Stomach ulcers
  • Chronic increase in gastrin (hormone that stimulate secretion of HCL in stomach) levels




Your dog's veterinarian will take a detailed history from you and perform a complete physical examination and laboratory tests on the animal. The results of routine laboratory tests, including complete blood profile, biochemistry profile, and urinalysis, may be variable depending upon the underlying cause. In dogs with severe ulceration, for example, anemia may be present. X-rays, meanwhile, may reveal a distended stomach due to stenosis of the pyloric canal. For more detailed results, your veterinarian may perform a gastrointestinal barium contrast study, in which barium sulfate is given orally to help highlight the location and extent of the narrowing on X-rays.



Another technique called fluoroscopy is sometimes employed. This imaging technique obtains real-time moving images of internal structures of the dog on camera with the use of a fluoroscope. The veterinarian may also employ endoscopy for detailed evaulation, in which he or she will look directly into the stomach and duodenum using an endoscope, a rigid or flexible tube that is inserted into the stomach and duodenum to visually inspect and take pictures of the region. Abdominal ultrasonography may also help in identifying the narrowing of the pyloric canal.



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