156 DISEASES OF THE STOMACH 



several times its normal thickness, with all the evidences of 

 a chronic inflammation. When no stenosis exists, the dila- 

 tation being produced by other causes, the muscular wall is 

 very thin and atrophic. In some cases the mucous mem- 

 brane shows areas of atrophy and hypertrophy alternating. 

 The interstitial tissue is often infiltrated with fibrous tissue. 



Symptoms.— In dogs the symptoms are very similar to 

 chronic gastritis. There is a partial or complete loss of appe- 

 tite, intense thirst, especially if the pylorus is obstructed, 

 the patients drinking large amounts of water which is after- 

 ward vomited. 



Constipation is also quite marked in most cases of chronic 

 dilatation. As no water can pass from the stomach to the 

 intestines, the contents of the intestinal tract become hard 

 and dry to be passed with difficulty, or retained as a hard 

 mass in the posterior part of the bowels. When dilatation 

 occurs without stenosis of the pylorus large amounts of water 

 will pass into the intestinal tract producing diarrhea, which 

 may alternate with constipation. Emaciation is usually 

 quite marked, especially in advanced cases, because no 

 nutriment can be absorbed. In some cases where there is 

 only a partial stenosis the emaciation will be more gradual, 

 as some food will be passed to the small intestines. Severe 

 pain, the animal often showing excitable symptoms, howling, 

 etc., is shown a short period after eating, due to the par- 

 ticles of food passing through the narrowed lumen of the 

 pylorus. Where no stenosis exists there is but little pain. 

 Vomiting is a constant symptom, especially in obstruction 

 of the pylorus, and usually occurs shortly after feeding. The 

 patient will sometimes eat the ejected mass again, only to 

 repeat the act of vomiting. This symptom is quite charac- 

 teristic coming as it does shortly after eating and continuing 

 in some cases in the same manner for days or even weeks. 



Gradually the animals become weak, anemic, the tempera- 

 ture subnormal, and die from inanition. 



Palpation over the region of the stomach will often reveal 

 the enlarged organ with its contents; percussion gives a 

 tympanitic sound. 



