In leucæmic conditions the red blood corpuscles are also present in fewer than the normal numbers. They are more irregular, assume giant and dwarf forms (macrocytes and microcytes), sometimes exhibit lacunæ, and are always polychromatophile, i.e., without special affinity for any particular constituent of double or triple stains.
Prognosis. The prognosis of diseases included in the lymphogenic diathesis is extremely grave, and in the present state of our knowledge it may be assumed that sooner or later death is inevitable.
Treatment. Treatment can scarcely be considered to exist, for at the best it can only delay the development of the disease. Nevertheless, and with this reservation, it is certain that preparations of iron, iodine and arsenic have a certain effect, probably by acting on the hæmatopoiesis.
CASEOUS LYMPHADENITIS OF THE SHEEP.
In the sheep the lymphatic glands are sometimes the seat of peculiar changes, which do not appear to have any marked effect on the general condition. Thus a post-mortem examination or an examination of animals in the slaughter-house sometimes shows a certain number of isolated or symmetrical glands, such as the mediastinal, tracheal, inguinal, pelvic or sublumbar glands, to be greatly enlarged and completely degenerated. The precrural, prescapular, and popliteal glands are said to be most frequently affected. Their contents are caseous and yellowish, enveloped in a fibrous sheath, and show no signs of peripheral inflammation. The other organs and viscera may either be healthy or exhibit caseous lesions identical with those found in caseous broncho-pneumonia.
The causes of this disease are imperfectly understood, although Cherry and Bull (1899, the Veterinarian, Vol. LXXII., No. 860, p. 523) have isolated from the lesions an organism identical with Preisz’s bacillus and with the microbe of ulcerative lymphangitis in the horse.
Norgaard and Mohler (Annual Report, United States Bureau of Agriculture, 1899, p. 638) have studied the disease. In June, 1897, Turski, at Danzig, found about 150 breeding ewes, from eight to twelve years old, suffering from nodules or abscesses the size of a child’s fist in the inguinal and prescapular regions. They had been sold for slaughter, and many were in very poor condition. The disease occurs in Europe, Western America, South America, and Australia. Several thousand cases are annually seen in the slaughter-houses of the United States.
The symptoms generally escape notice, and it is only by accident that one sometimes detects marked enlargement of the lymphatic glands of the neck or of the superficial inguinal glands. The patients, moreover, may remain in very good bodily condition, so that the lesions are only discovered on the meat being inspected.
Having regard to our imperfect knowledge of this disease, it is impossible to express an opinion as to its importance or treatment.