In certain cases movement causes groaning. In the slighter forms the patient may recover spontaneously. If fed with easily digested materials, the symptoms diminish in intensity. Towards the eighth day the fæces become normal, appetite and rumination reappear, and the secretion of milk which had fallen off rises to its normal amount. Resolution has occurred.
More frequently, either because the animals have less power of resistance or because decomposition is taking place more actively in the intestine, or, again, because intoxication is setting in, the disease becomes aggravated. Constipation is more marked, and the fæces passed are in small masses, covered with layers of epithelium, or sometimes streaked with blood. In other cases the diarrhœa becomes exaggerated and assumes a mucous or sero-mucous character; the temperature rises, and death results from exhaustion and infection, microorganisms passing from the lumen of the intestine through its walls and invading the general circulation.
Lesions. To study the lesions to advantage the autopsy must be performed as soon as possible after death.
In slight cases they consist of trifling generalised congestion of the intestinal mucous membrane. The points most affected show infiltration of the submucous coat, and sometimes of the muscular coat; the wall of the intestine is double its normal thickness, but the thickening never equals that seen in cases of rapidly fatal intestinal congestion.
At a more advanced stage the mucous membrane clearly is inflamed, its surface is covered with a fibrous exudate, and the glandular and epithelial cells proliferate, assume the embryonic form, and produce the new tissue which one recognises under the form of false membranes.
The false membranes are generally but slightly adherent, and are readily expelled.
In other cases, however, they adhere firmly, and when detached by the friction caused by movement of semi-digested food through the bowel, produce rupture of capillary vessels; this explains the presence of blood streaks in the fæces.
The diagnosis is relatively easy, especially at the onset, on account of the special character of the fæces and the sensitiveness of the right flank.
The prognosis is seldom grave. If the enteritis is taken at the beginning, recovery is usual; but if the animal has been ill for eight or ten days and is exhausted, and if fever and diarrhœa are intense, the prognosis should be guarded.
The treatment is that of all acute inflammatory diseases. Mustard plasters may be applied to the chest and abdomen and left in position for some hours, or may be repeated. Some practitioners prefer hot blankets or dry friction, or, again, rubbing with essence of turpentine, but this substance should be spread over large surfaces, in order to prevent injury to the skin. Bleeding is only justifiable in plethoric animals, and should never be exhaustive.