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.
_A deficiency of earthy salts in the food_ has been a natural and
favorite explanation, and the ill-health that is thereby brought about
is often an important factor. Yet rachitis occurs independently of such
a condition.
In Roloff’s experiments, pigs fed on aliment deficient in lime salts,
suffered from bone softening, while the control animals on food rich in
lime salts remained well. The diseased animals further recovered on a
diet rich in lime. Voight, Chossat, Milne-Edwards, Lehmann,
Bousaingault, Heitzmann, etc., had similar experimental results, and the
effects were shown in goats, sheep and dogs, in curvature, shortening,
swelling of the costal cartilages and joints and contracted pelvis.
Growing pigs have often been found to suffer in this way when placed on
an exclusive diet of maize. The great improvement often secured in
feeding an excess of calcareous phosphates tends to corroborate the
hypothesis. Wagner found that food rich in lime salts, and the
administration of small doses of phosphorus, rendered the epiphyses of
the growing bones more compact. Kassowitz, on the other hand, found that
an excess of phosphorus caused absorption from the bone substance and an
irritable inflammation of the osseous tissue. Schneidemühl has seen the
disease in calves raised on milk, poor in lime, the product of emaciated
cows; in pigs getting only potatoes and swill, and in puppies that were
denied bones. It is common in pigs on an exclusive diet of maize. Yet it
is most destructive in many breeding studs where the alimentation is
rich and generous. It must be admitted that as a concurrent cause, the
paucity of lime salts and phosphates is a powerful factor, and that in
supplying the bone ash, and improving the nutrition, these often prove
of great value. Their privation is, however, not an essential condition
of rachitis.
_Free phosphorus._ Ziegler and Kassowitz emphasize the hyperæmia of the
cancellated tissue, and Wagner shows that this condition can be induced
by excess of phosphorus, but this excess of phosphorus has not been
found in the blood in ordinary cases, and is not likely to occur in a
great number of young, at the same place and time, irrespective of food,
as has been shown in breeding studs in New Jersey, in the South and
West. In particular cases excess of phosphorus may operate, but it
cannot be looked on as universal or essential.
The presence of _glycero-phosphoric acid_ is alleged by Trasbot, but
there is no proof of its constancy in rachitis, nor would its presence
explain the real cause of the disease.
_Lactic acid in the system._ Lactic acid, in vitro, dissolves the
calcareous salts of the bones. Trasbot alleges that it opposes the
precipitation of lime in the form of tribasic phosphate, as found in
bone. Siedamgrotzky and Hofmeister found that the salts of the bone were
lessened under the administration of lactic acid. Heitzmann and Baginsky
showed that by restricting the lime in food and giving lactic acid, by
the mouth or subcutem, the lime salts in the bone were lessened
relatively to the organic basis. It should be noted that an exclusive
diet of buttermilk is liable to cause an attack of arthritic rheumatism.
Lactic acid is undoubtedly a coöperative factor in certain cases, but
though often found in the diseased bone and urine of rachitic children
(Ragsky, Morehead, Simon, Lehmann), it is not shown to be constant.
_Oxalic acid. Acetic acid. Formic acid._ Beneke found oxalic acid in the
urine in many cases of rachitis and attributed to it the removal of the
lime salts. Others have made the same charges on acetic and formic acids
which are sometimes found in the diseased bone.
It is quite plain that the process of normal ossification is easily
disturbed, and that the same agent (lime, phosphorus) will assist or
hinder according as it is present in small or large amount, and that
certain chemical agents like organic acids may act injuriously even in
the presence of an abundance of bone salts.
_Heredity._ Rickety parents have often rickety offspring, the weak
somatic cells, failing in both cases to build healthy, strong tissues,
but as a rule also, both have been condemned to live in similar
unwholesome surroundings.
_Unhygienic Conditions._ Schneidemühl notes that in animals as in man,
bad ventilation, close impure air, crowding, damp impervious soils, and
cold, are found more or less in places where rachitis prevails. By
lowering the general health and tone, these debilitate the tissue cells
and impair nutrition and growth.
_Confinement_ has a manifest influence. Rickets prevails in children in
the great manufacturing cities, where the exclusion of sunlight and the
breathing of impure air rob the system of its vigor. The children of
soldiers in India kept in close barracks are largely rickety, while the
more poorly fed native children outside escape. Wild beasts in
confinement are often rachitic, unlike their fellows of the forest.
Colts in confined stables suffer while those in the fields and yards
remain healthy. Swine in Sweden in close pens and fed on potatoes alone
suffer (Stockfleth).
_Darkness_ usually coincides with confinement and it is noteworthy that
deep sea fishes, living in comparative darkness, have usually
cartilaginous skeletons.
_Infection._ Certain facts seem to point to a direct infection, as
coöperating with the debilitating conditions above named. The advent of
the disease in England about 1700: its frequency in English swine on the
European continent (Schneidemühl); and its enzootic prevalence in
different parts of America, give seeming support to the doctrine.
Dr. W. L. Williams has seen it appear on an Illinois farm twenty years
after reclamation from virgin prairie, prevail for ten years and then
disappear. There was a remarkable coincidence of recurrent ophthalmia,
and disease of the bones and joints (navicular disease, spavin, splints,
ring bones, etc.).
In most of these cases the trouble occurred on low, damp or impervious
soils, agreeing with rickets in children, which avoids the Alps or hilly
districts, and abounds in valleys or bottom lands.
_Symptoms._ The colts show a lack of thrift and though there may be no
lack of growth or size, they have a rough coat, a poor development of
the neck, arching of the back and drooping pelvis. The chest may seem to
sink between the scapulæ. They move stiffly with swaying of the limbs,
or even staggering and are easily wearied or lacking in endurance. They
lie a great portion of their time or even persistently, refusing to
rise. When up they do not hold the limbs plumb, but allow them to
deviate one way or another in an unsightly way. There is liable to be
swelling of important joints of the limb, (knee, hock, stifle, fetlock),
which are tender to pressure and kept partly flexed. The ends of the
ribs are often enlarged. Bending of the long bones (tibia or radius),
and deviations of the back or sternum from the straight line are
significant. Thickening of the ends of the bones, or in the region of
the epiphyseal cartilages are largely diagnostic. The bones are easily
fractured. In _swine_ fed on potatoes, corn, etc., besides the
affections of the limbs, the thickening of the bones and swelling of the
joints, especially the hock and pastern, there is enlargement of the
nasal and maxillary bones so as to seriously obstruct breathing
(“Snuffles”). The teeth suffer and break readily and in the general
break down diarrhœa, bronchitis or skin eruption appears and the subject
falls into marasmus and perishes. In the necropsy arthritis is commonly
found. In _cattle_ beside the epiphyseal swellings, the bow legs and
joint enlargements, the back becomes crooked, vertically or laterally.
The same general symptoms appear in _dogs_ in which bow legs are a very
prominent feature. Goats suffer badly and mostly remain recumbent.
_Birds_ suffer most, showing knotty thickening of the bones of the legs
and wings, and flexibility of the bones generally but above all of the
keel of the sternum, which is usually badly distorted from sitting on
the perch.
In all alike there are usually a few days of fever, followed by
indigestion, colics, anorexia, and a general air of illness. Then appear
the lameness, stiffness and swelling of bones and joints. Any joint may
suffer, shoulder, elbow, knee, hips, stifle, hock, or fetlock. The
lameness may shift as in rheumatism, it may intermit, occurring
periodically, or it may advance uninterruptedly to a fatal issue.
Paraplegia is common and appears to be due at times to pressure on the
spinal nerves by the diseased vertebræ. Before this becomes complete,
the animal may walk with the whole digits and metatarsi in contact with
the ground, and the softened crumbling calcis may project through the
skin forming an unsightly sore which soon becomes septic. The same
happens at times to the point of the elbow.
_Treatment._ The most important, are the hygienic considerations. Reject
weak or cachectic animals from breeding, and those that have been
rachitic to a marked degree, as their progeny are likely to show the
same weakness. Change the ration giving one that is well balanced and
rich in nutritive matters and earthy salts. Clover, alfalfa, and a
generous grain diet may serve as an example for herbivora, and a fair
allowance of meat and bones for dogs. Food from land that has apparently
contributed to the disease in other cases is best avoided. If the land
is poor, sandy, or destitute of earthy salts and phosphates, so much the
more is it to be suspected and set aside. In the case of sucking animals
it should be seen that the milk is rich and abundant, and that it is not
too rich in fat, nor otherwise calculated to disagree and induce
indigestion. Above all soured or otherwise fermented milk should be
withheld, and any buckets or troughs used in feeding should be regularly
washed, scalded and disinfected. In case colts, or dogs are being raised
on cow’s milk it may be requisite to dilute it with one-third its volume
of barley water, or solution of gum arabic, and to sweeten with sugar.
Lime water with each meal is valuable in counteracting acidity, and
fermentation, and in furnishing lime which may be absorbed in part.
In prevention and treatment alike, fresh air and sunshine must never be
neglected and in warm weather, an outdoor life, night and day is of the
greatest value. At the same time cold storms, damp beds, or any
condition which may induce chill must be excluded. Close stalls, pens,
or kennels must be absolutely forbidden.
Among medicinal agents antacids are often essential on account of the
acid condition of the ingesta, lime water will often suffice, but if
there is manifest constipation calcined magnesia three times a day on an
empty stomach so as to counteract costiveness will often serve a good
end. The atony of the bowel may be further met by small doses of
strychnia. Other bitters may be used if this has little effect. Small
doses of phosphate of soda, or bone dust have been long lauded in the
affection, and probably act beneficially as a tonic as well as a food
material. Phosphorus in minute doses tends to increase the deposit of
earthy salts and consolidate the bones. Large doses induce hyperæmia of
the epiphyseal ligament and even favor fracture. A grain of phosphorus
daily may be given in olive oil or better in cod liver oil which acts as
a valuable tonic. Dieckerhoff recommends the intratracheal injection of
the solution of phosphorus in olive oil.