Jeswejenko records that of a four year old English thoroughbred which after a race showed anorexia, weakness, thirst, rapid pulse, palpitations, conjunctivitis, enlarged thyroid and after fourteen days exophthalmia with thyroid pulsations. It died in the fourth week, anæmic and exhausted. A second case in a 7 year old bitch recovered in three months under treatment with iodine.
Röder gives the case of a cow with palpitations, abnormally strong pulsations, thyroid hypertrophy and double intense exophthalmia. This persisted for four years.
RACHITIS. RICKETS.
Definition. Lesions and pathology; gastro-intestinal disorder, hepatic, splenic and renal congestion and hypertrophy, lessened blood salts, dilated arteries, hyperæmia of bone, deep red marrow, blue articular cartilage, softening of epiphyseal cartilage and under the periosteum, with hyperplasia, decrease of lime salts, bending of bone, loose periosteum; sclerosis in repaired cases. Causes: appears as if infection, lack of lime salts in food, inconstant, free phosphorus, glycero-phosphoric acid, lactic acid, oxalic, acetic and formic acids, heredity, bad air, crowding, damp soils, cold, confinement, darkness, infection, toxic matters. Symptoms: unthrift, thin neck, arched or hollow back, drooping pelvis, weariness, stiffness, recumbency, limbs not plumb, tender, swollen puffed joints, enlarged epiphyses, bent shafts, or spine, brittleness. Swine fed on potatoes or corn, “snuffles”, breaking teeth, diarrhœa, bronchitis, skin eruptions, arthritis. Cattle, epiphyseal swellings, bow legs, crooked back. Dogs, bow legs. Goats. Birds, knotted thickening of bones, flexibility. Fever, colics, indigestion. Lameness shifting, intermittent, relapsing. Paraplegia. Treatment, hygienic, vigorous breeding animals, nutritious rations, rich in earthy salts, well balanced, from sound land, rich abundant milk without excess of fat, avoid spoiled food, adapt cow’s milk to foal or puppy, fresh air, sunshine, damp soils, antacids, lime water, laxatives, bitters, phosphates, bone dust, phosphorus.
Definition. A constitutional disease of young animals, associated with disorders of digestion, nutrition, assimilation, and sanguification, and especially characterized by softening and distortion of the bones.
Lesions and Pathology. Apart from the bones there does not seem to be an absolute constancy in the lesions. There is usually, however, a period of ill-health and faulty nutrition before the lesions in the bones can be recognized. Thus, there may be gastric or intestinal congestion, or catarrh, indigestions, constipation alternating with diarrhœa, enlargement of the liver, spleen and kidney with hyperæmia, and according to V. Jaksch, a diminution of the salts of the blood. Beneke found that the arteries are dilated throughout the entire body, but the heart does not always participate in this distension. The arterial dilatation is very marked in the pulmonary artery, yet the lungs are relatively small. In the bones there is a well marked hyperæmia, most prominent beneath the periosteum, in the cancellated tissue, the line of junction of the epiphysis and diaphysis, and near the articulating surface. The contents of the cancelli are of a deep red, and the color shines through the articular cartilage giving it a bluish tinge. The shaft of the bone does not escape, but like the epiphysis and epiphyseal cartilage may be soft and yielding to pressure, and cut readily with the knife.
At both points the process of growth is increased and its area extended, but it is not completed by the full deposition of earthy salts, and the softening is not confined to the new tissues, but extends into the subjacent bone as well.
The chemical composition of the bone is profoundly altered, the organic basis, at times amounting to 65 per cent., as compared to 33.30 per cent in the normal bone. The softened bone, yielding under the weight of the body, bends out of shape at the epiphyseal cartilage, or even elsewhere, giving rise to bow legs, deviation of the joints inward, or other distortion. The periosteum is red, thickened, the seat of exudate and easily torn from the bone.
The bones are often thickened by new deposit under the periosteum and especially at the junction with the epiphyses. Old cases of distortion, the result of rickets, do not necessarily show a deficiency of earthy salts, as these are restored in case of repair and they may even be found in excess of the normal, increasing the hardness of the bone.
Causes. This disease does not seem to have been recognized in Great Britain until the beginning of the 17th century, the period of England’s early activity on the sea, and the beginning of extensive commerce and manufactures. From that time it has been increasingly and extensively prevalent. Yet it has not been shown to be propagated by any specific germ, nor to have extended in line with the introduction and use of new food products like the potato. It appears to be traceable rather to unwholesome conditions of life and a reduction of the general tone and nutritive vigor.