“Later, appetite and milk secretion fail, temperature rises a degree or two, the animal refuses to rise, remaining down twelve to twenty-four hours at a time, and ... when rising ... remaining on the knees for a time, moaning and indisposed to exert itself further. At this stage many cases begin to improve and may get well in five or six weeks. Some will remain down for several weeks and finally get up and recover. With constant decubitus, however, the animal falls off greatly, becoming emaciated and weak, the appetite may fail altogether, and the patient is worn out by the persistent fever, nervous exhaustion and poisoning from the numerous bed-sores ... which are common over the bony prominences. It is in these last conditions, above all, that fractures and distortions of the pelvic bones, and less frequently of the bones of the legs occur.”
Fig. 5.—Head of a pig suffering from osseous cachexia.
“The disease may advance for two or three months, and in case of pelvic fractures and distortions, there may be permanent lameness, and dangerous obstruction to parturition, even though the bones should acquire their normal hardness through the deposition of lime salts.”
In horses, the different phases of the disease develop precisely as in bovines. The apparent differences between affected horses and cattle result in reality from differences in their capacity for continuing work. In the first phase, horses are incapable of work, their movements being badly co-ordinated. They are inclined to stumble, and appear as though suffering from strain of the lumbar muscles.
In the second phase pain referable to the bones sets in. Lameness develops without visible lesions and is rapidly followed by synovitis and arthritis in the lower portions of the limbs, and by wasting and anæmia.
The animals seem unable to move rapidly, or if forced to do so may sustain fractures even at a trot: the limb bones sometimes break or ligamentous insertions in the neighbourhood of joints are torn away, resulting in sudden falls on the ground and fracture of ribs or even of the vertebral column. This corresponds to the third phase, osteoclastia, in oxen.
Fig. 6.—Osseous cachexia. This condition developed in two months, the last month of gestation and the first of lactation.
From then onwards, horses become useless and, if not destroyed, may, after a few weeks or months, develop the condition known as osteomalacia, in which the flat bones become softened, the head, the branches of the lower jaw and the face become deformed, while mastication and other functions are impeded.