The temptation under such circumstances is to deliver a diagnosis of simple pneumonia with prognosis of probable recovery. It should be remembered, however, that in all cases of basilar pneumonia without affection of the anterior lobes there is a considerable chance of the condition being due to the presence of a foreign body. On more careful examination it is found that the intercostal spaces opposite the affected region are very sensitive, and that the circle of the hypochondrium is correspondingly sensitive. The owner, moreover, almost always informs the practitioner that for several weeks his animal has coughed, shown tympanites, diminished appetite, etc. Compression of the roots of the corresponding diaphragmatic nerve at the base of the neck always produces coughing. These symptoms rarely accompany the development of simple pneumonia. Furthermore, the =course= of this accidental pneumonia is entirely different. Instead of developing regularly according to the above-described cycle, pneumonia due to foreign bodies develops slowly, and only becomes well defined after several weeks, whilst its tendency is to grow more and more aggravated. The zone of dulness extends both in a forward and upward direction. The souffle extends forwards. Auscultation and palpation sometimes reveal the formation of an abscess or local gangrene; while there is slight œdema of the wall of the chest, as well as a gurgling sound at the moment when the lung is displaced, high fever, intensely coloured urine, and very marked leucocytosis, etc. Death is inevitable, and when gangrene exists it sometimes occurs suddenly. =Diagnosis.= The diagnosis is based on the information furnished with regard to the course of the disease, the localisation of the hepatised zone, and the progressive character of the affection. The diagnosis, nevertheless, is always a little doubtful, but may be so far assured as to attain the position of a quasi-certainty. =Prognosis.= The prognosis is unequivocal.