Under the influence of depraved appetite animals of the bovine species consume, apart from their regular food, the most varying substances, such as linen, fragments of wood, nails, stones, gravel, sand, etc. Moreover, forage, even when of good quality, often contains foreign bodies like nails and pins (when the fields are near factories), sewing or knitting needles (when the animals are looked after by women), fragments of iron wire derived from bales of compressed forage, etc., etc. The ingestion of such objects is followed by various consequences, which may be studied in three divisions, in the first of which the foreign object is soft in character, in the second is blunt at one extremity and pointed at the other, and in the third is pointed at both ends.
(1.) Soft objects. The movements of the rumen, the warmth and the action of the digestive fluids, may cause soft objects to be broken up; the disturbance they produce is then insignificant.
Of such substances, however, some are quite incapable of digestion (clothing, sacks, linen, etc.), and may produce obstructions; others are both indigestible and heavy (gravel and sand), and may fall into the depressions of the compartments, where they remain, or, if passed into the reticulum, may become arrested in the deepest lying part. They then produce atony of the muscular coats, slowing of peristaltic movements, diminution in the frequency of eructation, and, as an additional consequence, chronic tympanites, sometimes visible at the flank.
The symptoms are vague and common to a number of the digestive diseases already described. The animals masticate without having anything in the mouth; rumination becomes irregular or is altogether suppressed, but this is not characteristic, being a symptom common to many visceral diseases.
Later, as a result of auto-infection, diarrhœa sets in; under the influence of abnormal fermentation in the gastric compartments the eructations become fœtid; the animals fall into a condition of marasmus. Death usually results after a varying time—when large quantities of foreign substances have been ingested, in twenty to thirty days.
The diagnosis chiefly rests on the history, and can only be of a confident character when one knows what quantity and what kind of foreign body has been swallowed.
The prognosis is grave, because the animal usually dies of progressive exhaustion.
Treatment. There is only one rational form of treatment—viz., gastrotomy, followed by examination of the rumen and reticulum and removal of the foreign body. Before undertaking operation the surgeon should be fully informed as to the cause and the probable results to be expected.
(2.) Foreign bodies with one pointed extremity. These usually consist of large-headed nails, or fragments of iron wire rolled up at one end, which have been swallowed during primary mastication along with forage.
When ingested, they may become implanted at any point in the gastric apparatus without necessarily penetrating deeply. When fixed across the division of the reticulum, they cause slowing of its physiological action. Should they penetrate the wall either of the reticulum or of the rumen, they may attack on the right the liver, or on the left the diaphragm or spleen, producing suppurating hepatitis, splenitis, or respiratory disturbance. The hypochondriac region then appears sensitive. The muscular portion of the diaphragm is partly paralysed, and costal respiration set up, while frequent coughing of reflex origin is provoked by irritation of the pneumo-gastric and diaphragmatic nerves, and may give rise to suspicion of some thoracic disease, from which, however, it is distinguished by the absence of discharge, expectoration, and pulmonary symptoms.