The heart is affected reflexly or directly as a result of generalisation of the tumour, and the pulse may rise to 70 or even 120 per minute.
During the first stages neither auscultation nor percussion points to any pulmonary lesion. At a later stage the lung itself may be affected. The other important functions are normal.
Animals suffering from sarcoma, carcinoma, or lympho-sarcoma of the mediastinum waste very rapidly, lose appetite, become feverish, and soon develop cachexia.
Diagnosis. The diagnosis of tumour of the mediastinum is easy, because of the well-marked character of the apparent symptoms.
Prognosis. The prognosis must be regarded as extremely grave, and in most cases fatal, for there is no active method of intervention, extirpation being impossible.
There is no treatment. The animal should at once be slaughtered.
SECTION IV.
THE ORGANS OF CIRCULATION.
SEMIOLOGY OF THE ORGANS OF CIRCULATION.
The semiology of the circulatory apparatus comprises the clinical examination of the heart, arteries and veins, and the examination of the pulse and blood.
Heart. In animals of the bovine species, the heart is situated in the thoracic cavity opposite the third, fourth, fifth and sixth ribs, nearly in the median plane of the thorax, and inclined from front to back at an angle of 70 degrees.