These various fermentations, which may be of the lactic, butyric, and even putrid order, produce changes in the mucous membrane of the rumen; wide tracts of the epithelium may be shed, exposing the corium, and producing enormous ulcerations, which in certain cases implicate the entire inner surface of the rumen.
The treatment must be varied, according to the cause, symptoms, and immediate complications. When the disease is of an acute type, such as that produced by over-gorging with lucern and green food, it is best to proceed as in gaseous indigestion, i.e., to puncture the rumen and give frequent large doses of purgatives until the stomach and bowels have been freely unloaded. The animals should then be kept for some days on small quantities of easily digested food, and should be allowed lukewarm, mucilaginous drinks.
When tympanites and impaction occur simultaneously, immediate surgical intervention becomes necessary, and gastrotomy may then be performed by a very simple method.
Two loops of cord are passed around the abdomen, one behind the hypochondriac circle, the other in front of the angle of the haunch. Assistants placed on the right side draw these loops tight, so as to immobilise the left flank. A bistoury is then thrust directly through the walls of the abdomen and rumen. As a consequence of the pressure exercised by the ropes, if not of the pressure of gas itself, the food material contained in the rumen is often expelled in a powerful stream. As the superposed tissues cannot very readily change their mutual relations, the author of this suggestion claims that there is little danger either of infectious materials passing into the subcutaneous connective tissue, or of peritonitis; but this rude treatment can only be resorted to in cases of extreme urgency, and it appears by no means without danger.
Injections of 10 to 15 centigrammes of pilocarpine and 5 to 10 centigrammes of eserine are also useful.
When impaction of the rumen assumes a less acute form, moderate doses of purgatives may be given and repeated daily, or twice a day, until the peristaltic action of the rumen is restored and resumes its normal rhythm. In certain cases, however, recovery is only apparent. The food in contact with the walls of the rumen breaks down, and passes away into the abomasum and intestine, while appetite returns. The animals then resume feeding, and some days afterwards show all their former symptoms. Low diet should therefore always be continued for some time.
In spite of treatment, or in consequence of treatment being too long delayed, no improvement may follow. The ingested food is not expelled. Putrid fermentation results, auto-intoxication sets in, and the temperature rises to 40° or 41° C. Unless gastrotomy is performed death is then certain.
This operation should be undertaken whenever the fever rises to 40° C., and two-thirds of the contents of the rumen removed. The rumen should not be completely emptied, as there is danger of collapse of its walls. Complications in the region of the wound can be avoided by drainage.
If the operation succeeds, the patients must be placed on very low diet or on milk for some days, and should be given lukewarm farinaceous drinks, and a little hay of good quality to excite rumination. In old milch cows this operation is seldom followed by a satisfactory recovery. Apart from the loss of milk, the animal loses condition, refuses to feed, and gradually succumbs to exhaustion.