=The lesions= comprise abnormal vascularity of the mucous membrane and desquamation, and even gangrene, of the leaves. The partially digested food is not passed on, becomes dry and hard, and in time aggravates the local condition. =The treatment= does not essentially differ from that of other gastric inflammations. The object to be attained is to evacuate as completely as possible, not only the omasum, but all the gastric reservoirs, for which purpose one may freely administer demulcent drinks—linseed gruel, bran mashes and lukewarm liquids containing laxatives. At first such alkaloids as arecolin and pilocarpine may be subcutaneously injected to ensure energetic and speedy evacuation. Later on slightly stimulant aromatic infusions, like infusions of sage, peppermint, hyssop, thyme, etc., stimulate the functions of the stomach and hasten the return of normal conditions. ACUTE GASTRITIS. The term “acute gastritis,” sometimes “gastro-enteritis,” is used in bovine pathology to indicate inflammation of the abomasum. If this inflammation is confined to the superficial epithelial layers it is defined as superficial catarrh of the abomasum; if, on the contrary, it extends to the deep epithelium of the gastric glands and to the mucous corium, it is termed deep-seated gastritis. Clinically it is impossible to make these distinctions. We simply recognise degrees of gravity, and only in this way can one diagnose acute gastritis, phlegmonous gastritis, ulcerative gastritis, etc. =Causation.= The abomasum frequently becomes inflamed as a consequence of irritant foods, apart altogether from lesions of the rumen or reticulum, the mucous membrane lining the abomasum being so much more delicate than that of either of the two first compartments. Irritant plants, parasites, acid drinks, very cold water, certain acid or toxic industrial residues like mouldy brewers’ grains, fermented vegetable pulp, decomposed beet, etc., and mouldy or spoilt forage of any kind may all produce acute gastritis. Intense feeding—_i.e._, feeding with farinaceous materials, with large quantities of beans, roots, peas, given regularly—may also cause gastritis by overtaxing the functions of the organ. Frozen or fermented roots and sudden changes in feeding produce similar results. Chills have also been blamed, but it is probable that they only act as favouring causes. =Symptoms.= It is necessary to consider these very carefully in order to arrive at a correct diagnosis. Inflammation of the abomasum is attended with moderate fever, diminution in appetite, irregularity in rumination and some tension of the rumen, without, however, true tympanites.