Symptoms. As may readily be imagined, the symptoms vary, according to the quantity and digestibility of the food swallowed. In the first place the appetite falls off: animals suffering from commencing indigestion only take part of their food; later on appetite ceases, and with it rumination. Trifling colic sets in, resembling that due to congestion, and is indicated by unrest, switching of the tail, lifting of the hind legs, slight groaning, moving from side to side, and lying down and rising at short intervals. The animals seem oblivious of their surroundings, anxious, and at times semi-comatose.
When the case has been neglected for several days the animal may masticate without having any food in the mouth, and may attempt to eructate and to regurgitate food; but such attempts always fail. It then absolutely refuses food, and animals which have eaten large quantities of green forage may show tympanites. If called in at this period of the disease the veterinary surgeon finds nothing positive except signs referable to the digestive apparatus. By methodically examining the digestive tract, and in particular the stomachs, one discovers during palpation of the left flank that the rumen is distended. This is characteristic. By deep palpation it is even possible to detect marked resistance and a certain characteristic firmness resulting from accumulation of food. The percussion sounds over this region are dull, and pressure causes pain, as though the rumen and peritoneum were inflamed. When the open hand is laid flat on the rumen and thrust downwards, no peristaltic movement can be discovered. Finally, on auscultation the normal sounds, including crepitation, fermentation, and rolling sounds are all absent.
There are no well-marked general symptoms. Respiration and circulation are hardly accelerated, nor is the artery particularly tense.
Course and Termination. The course of the disease varies, and the condition may be divided into two forms, acute and chronic. The first develops in a single day, and may cause death by the same mechanism as acute tympanites—i.e., asphyxia or carbonic acid poisoning; the other continues for five, ten, or even twenty or thirty days, according to the promptitude with which treatment is undertaken.
In protracted cases, however, the indigestion itself ceases to be as important as the complications. Sometimes spontaneous recovery occurs, the food passing away towards the intestine, or even being vomited, though the latter conclusion is rare. Recovery may also follow from treatment. If the disease is neglected it may become complicated with gastro-enteritis.
The diagnosis is not very difficult. Indigestion resulting from impaction is distinguished from acute tympanites by its less rapid course and by the less marked distension of the rumen (in this case due to solid food), and from acute gastro-enteritis by the varying degree of fever which accompanies the latter condition.
Prognosis. The prognosis is always grave, even in cases of acute indigestion resulting from eating green food.
In this case gaseous indigestion occurs as a complication, and necessitates immediate intervention. The other forms may rapidly yield to proper treatment, or, in spite of every care, may give rise to prolonged complications.
Lesions. On post-mortem examination of animals which have died of complicated forms of the disease, we find certain lesions peculiar to gaseous indigestion associated with impaction of the rumen.
If death has followed the consumption of root pulps, we see signs of poisoning. As a consequence of prolonged stagnation of food in the rumen, there follows an exaggerated organic fermentation, whose products are absorbed through the stomach or intestine and pass into the circulation.