Interruption of the local circulation in the deeper parts of the mucosa as in inflammation and capillary thrombosis, arterial embolism, venous thrombosis, may lead to local sloughing and ulcerous infection. This may be seen in the petechial fever of the horse, malignant catarrh, rinderpest, and anthrax in cattle and sheep, and in canine distemper in dogs. Vogel found ulcers resulting from a gastric aneurism in the dog. Tumors and infective growths in the walls of the stomach may prove an occasion of ulceration. Thus sarcoma, epithelioma, actinomycosis and tubercle may be the primary morbid lesion in different cases. Gastric ulcers have also been attributed to morbid nervous influences as in dogs they have been found associated with lesions of the dorsal myelon, and the corpora quadrigemini, and faradisation of the vagus has apparently led to their production. General constitutional debility has been alleged as a factor, and experimentally in dogs, the hypodermic or intravenous injection of various microbes or their toxins (diphtheritic toxin, Enriquez and Hallion, staphylococci, Panum, Lebert, Letulle, and a bacillus of dysentery in man, Chantemesse and Widal), have produced gastric ulcers. _Symptoms._ In _horses_ and _cattle_ these are very obscure, being mainly in the nature of chronic gastritis. In both there are recurrent attacks of slight colicy pains, with tympany in cattle, and gradual emaciation. Vomiting has been exceptionally seen in both class of animal and if the rejected matters are very acid and above all if mixed with blood it is more suggestive of ulcer. In the horse the attacks of colic are mostly in connection with eating. or (in case the ulcer is duodenal) an hour or two after a meal. In this animal it is possible to withdraw liquids from the viscus by the stomach pump, and any hyperacidity or blood may be almost diagnostic. Tenderness to pressure on the epigastrium or hypochondrium is often present, yet the colics of ulceration are often relieved by pressure and friction. Blood is sometimes present as such in the excrements, but more commonly these are simply blackened by the exuded blood as acted on by the gastric acid and intestinal liquids. The bowels may be alternately constipated and relaxed. A gradually increasing feebleness is a characteristic feature and in cattle paraplegia may precede death.