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.
At first the bowels are constipated, but in time fœtid diarrhœa sets in. Examination of the digestive apparatus on the left side and in the right posterior abdominal region reveals nothing abnormal, but pressure over the lower portion of the abdomen and along the cartilages of the right hypochondriac region produces, on the contrary, well-marked pain. This region corresponds to the position of the abomasum.
The conjunctiva appears reddish yellow, as in most visceral inflammations.
Some authors have described attacks of extreme excitement, but these are no more pathognomonic than is grinding of the teeth, which is a constant symptom, or the metallic sound noted on auscultation of the rumen. This sound occurs in all cases of inertia of the rumen, and indicates distension and emptiness of the viscus (acute peritonitis, chronic adhesive peritonitis, inflammation of the reticulum as a consequence of the presence of foreign bodies).
Dull colic and groaning are not uncommon. Finally, Thierry and others have all mentioned an alliaceous smell of the eructations as pathognomonic.
Acute gastritis develops regularly in ten to fifteen days, after which the symptoms diminish and disappear, giving place to normal health. In grave cases, despite proper treatment, acute gastritis more frequently ends in a chronic condition, finally leading to gastric atrophy, and the insufficient secretion of hydrochloric acid, with all the consequences of these conditions. The glands of the stomach degenerate; the secretion becomes abnormal and dyspepsia is set up.