Vagus indigestion refers to gradual abdominal distension associated with interference with normal emptying of the forestomachs (particularly rumen and reticulum). The condition may be caused by damage to the vagal nerve from a variety of causes (pharyngeal trauma/abscess, mediastinitis, infection or abscessation in the thorax or anterioventral abdomen such as with traumatic reticuloperitonitis). It may also result from mechanical inhibition of stomach motility from adhesions without damage to the vagal nerve, from impaction with dry, coarse feed or from obstruction in heavily pregnant cows resulting from displacement of the stomachs by the pregnant uterus.
The most common cause of localised peritonitis is traumatic reticuloperitonitis (see Traumatic reticuloperitonitis).
Ballottement will detect a large fluid filled rumen which may disguise extent of loss of body condition. The differential diagnosis is rumen acidosis.
Treat with antibiotics (procaine penicillin, oxytetracycline, or ceftiofur) and feed hay as a portion of the diet to try to stimulate normal rumination. Salvage slaughter or euthanasia may be appropriate for some cases.
Ensure feedstuffs are not contaminated with nails, needles or short pieces of wire.