The patient exhibits no other symptoms, the principal functions of the body appearing to be properly performed. There is no fever, but in time the animals lose condition and waste away.
Causation. This disease is also well known in man, but no general agreement exists regarding its nature. Some refer it to disturbance of the thyroideal function, though scleroderma is quite different to myxœdema. Others attribute it to changes in the cutaneous blood-vessels, others, again, to peripheral neuritis accompanied by atrophic disturbance. Nothing, however, is proved.
The apparent lesions are limited to hypertrophic sclerosis of the dermis, with progressive atrophy of the layers of subcutaneous adipose tissue.
The diagnosis is comparatively easy.
The prognosis is grave, because it is never known how rapidly the disease may develop.
No method of treatment being known, the animals should at once be slaughtered.
CHAPTER V.
SUBCUTANEOUS EMPHYSEMA.
By subcutaneous emphysema is meant the condition produced by the entrance of air or gas into the subcutaneous and interstitial connective tissue. Emphysema may remain localised or it may become generalised, according to the nature and extent of the lesion which causes it, and the points where emphysema is developed. Subcutaneous emphysema is common in the sheep and ox.
Symptoms. Sometimes the symptoms of subcutaneous emphysema are extremely well defined. They consist in the presence of diffuse or limited crepitant swellings which may appear at various points—in the flank or the entrance to the chest; more rarely in the region of the elbow, etc.
The limits of crepitation may be ascertained by palpation, while percussion produces a peculiar abnormal sound. The subcutaneous tissue and very often the interstitial tissue appear as though blown out.