Finally, if implanted in the lower wall or sides of the rumen or reticulum, foreign bodies may carry with them infectious agents and set up localised or generalised peritonitis.
Early diagnosis is a matter of great difficulty, as it can only rest on the diaphragmatic disturbance or on the symptoms of peritonitis.
Lesions. Small-sized sharp bodies cause lesions of trifling extent, which in most cases are only indicated by retardation of movement of the gastric compartments, between which and the diaphragm, and between the diaphragm and the posterior portions of the lung, various adhesions are set up. In such cases the peripheral inflammation ends by producing a fibrous sleeve, which prevents the pleural cavity becoming infected. Other cases show patches of adhesive peritonitis or signs of generalised peritonitis, the real cause of which often evades discovery during life.
Treatment. Gastrotomy is the sole means of effecting a cure, but we are forced to admit that it only gives good results when the operator knows what he is trying to find. Without this information he acts in the dark, is obliged to abandon himself to chance, and although luck sometimes favours him, it more often leaves him in the lurch.
(3.) Foreign bodies pointed at both ends. Bodies like needles, pins, straight fragments of iron wire, knitting needles and broken hairpins, become implanted in the gastric walls and travel in the most diverse directions, in obedience to the varied movements of the organ injured. They produce results similar to those just described. Most frequently they fall into the lower part of the gastric compartments, pass near the ensiform cartilage, between the pleura and the triangularis sterni into the thickness of this muscle, or into the mediastinum, and there produce either an abscess in the region of the ensiform cartilage, an abscess of the thoracic wall, or a collection of pus in the subpericardial or subpleural region (pseudo-pericarditis). They may even reach the pericardium, causing pericarditis, and sometimes, when adhesions are set up between the heart and pericardial sac, carditis.
By deviating to the right or left, the foreign body may produce pleurisy or even pneumonia. If it moves towards the right, it involves the liver and produces suppurative hepatitis; if to the left, suppurative splenitis. Travelling in a downward direction, it encounters the abdominal wall, and after producing an abscess may be eliminated; passing backwards, it falls into the peritoneum, and may lead to peritonitis. In those exceptional cases in which foreign bodies reach the abomasum they generally become implanted towards the greater curvature, producing in the abdominal wall an abscess which breaks externally, and through which the foreign body is discharged; gastric fistula is then a common sequel.
The symptoms vary, according to the complications. The earliest comprise digestive disturbance, which coincides with the passage of the sharp object through the rumen or reticulum, and depends on whether such passage produces local peritonitis and pain, rendering movement of these compartments impossible. Later, when the diaphragm has been penetrated, respiratory disturbance occurs, and is succeeded by apparent improvement, which in its turn may be followed by the occurrence of pericarditis, pleurisy, or abscess formation.
In other cases where suppurative hepatitis or splenitis, or even peritonitis may be present, the symptoms are extremely vague and very difficult to refer to their real cause.
Diagnosis is difficult, unless the owner is able to supply exact information that at some previous time the animal had swallowed such and such an object.
The prognosis is grave, though cases occur where a foreign body is tolerated, and may for a long time be retained without producing accidents.