Thigh 2-- 1 on each side.
Leg 6-- 3 on each side.
Hind foot 38--19 on each side.
---- Total 196
Without attempting to burden the reader with the technical names and a scientific cla.s.sification of each, it appears desirable to describe some of the characteristics of forms in general and of a few cla.s.ses into which they may be divided, leaving the special study of individual bones to the ill.u.s.trations of the skeleton (Pl. XXV), which will serve better than a great deal of writing to fix in the mind of the reader the location, relation, and function of each one. In early fetal life the place of bone is supplied by temporary cartilage, which gradually changes to bone. For convenience of study, bones may be said to be composed of a form of dense connective tissue impregnated with lime salts and to contain two elementary const.i.tuents--the organic or animal and the inorganic or earthy. In young animals the former predominates; with increasing years the relative proportions of the two change, so that when advanced age is reached the proportion of inorganic far exceeds the organic. The gradual change with advancing years from organic to inorganic has the effect of rendering the bone harder and more brittle, and though it is stronger, the reparative process is slower when injury does occur.
The bones are nourished in two ways: First, from the outside through their covering, called the periosteum--the thin, strong membrane that covers every part of the bone except the articular surface of the joints; and, second, from within through the minute branches of blood vessels which pa.s.s into the bones through holes (foramina) on their surface and are distributed in the soft structure (medulla) of the inside. The structure of the bone is divided into two parts--the compact or hard material of the outside, which gives strength and is more abundant in the shafts of long bones, and the cancellated, softer tissue of the inside, which affords accommodation to the blood vessels necessary for the nourishment of that part of the structure.
In shape, bones are divided into three cla.s.ses--long, flat, and short. The long bones are the ribs and those mostly found in the limbs; the flat bones are found in the head, the shoulder, and the pelvis; the short bones in the spinal column and in the lower portions of the limbs.
With this little introduction, which seems almost indispensable, we will proceed at once to the consideration of diseases of bones, for they undergo disease processes like any other living tissue.
OSTEITIS.
Inflammation of the compact structure of bones (osteitis) may be either acute or chronic, and may involve the whole extent of the bone affected or may be confined to only a portion of it. This inflammation results from injury, such as concussion, laceration, or a crushing bruise; also from specific influences, as in actinomycosis (lumpy jaw) or cases of foul foot.
The latter affection frequently involves the bones, and for this reason the pastern is the most frequent seat of osteitis. There is dull pain on pressure and a painful swelling of bone when pus is present. Suppuration may involve the overlying soft tissues, causing an abscess, which may finally break through the skin. The inflammatory condition sometimes a.s.sumes an ulcerated form (caries) or from interrupted nutrition of the part deprived of the blood necessary to its nourishment may cause death of a large section of bone (necrosis); this dead fragment (sequestrum), becoming separated from the main portion of bone, acts as a foreign body.
_Treatment._--This consists in resting the affected part and in giving vent at the earliest possible moment to whatever pus may be present. Free drainage should then be maintained. Apply dressings of lactic acid or inject with 5 per cent zinc-chlorid solution and pack with tampons of cotton soaked in antiseptic solutions. A laxative to keep the bowels moving freely is the only internal treatment necessary.
PERIOSt.i.tIS.
This disease is an inflammation of the external covering of bone (periosteum) and is usually produced by wounds, pressure, or crushing the part. The periosteum is well supplied with sensitive nerve endings and when inflamed is very sensitive to pressure and may cause lameness. This condition is often difficult to determine, and even an acute observer may fail to locate the point of its existence. There are three forms of periost.i.tis--aseptic, purulent, and fibrous.
ASEPTIC PERIOSt.i.tIS when it becomes chronic causes such a bony enlargement (exostosis) as is seen in the callous formation following the fracture of a bone. The formation of such a tumor or enlargement on the surface of a bone is liable to occur in any part of the bone covered with periosteum, and when found near a joint involving two or more bones it is liable to result in their union (anchylosis).
_Treatment._--Applications of cold water to check the inflammatory processes is indicated for the first few days in aseptic periost.i.tis, followed by hot fomentations to hurry resorption of fluids. Ma.s.sage should then be given with camphor ointment, mercurial ointment, soap liniment, or Lugol"s solution. In the chronic form point firing or a biniodid-of-mercury blister will be found beneficial.
PURULENT PERIOSt.i.tIS follows wounds which reach the periosteum and become infected, as observed in compound fractures, or it may result from advancing purulent conditions in neighboring structures, as in foul foot.
It may also occur in the course of an infectious disease, when small abscesses are formed under the periosteum (subperiosteal abscess). It may lead to necrosis of the bone or a fistulous tract from the bone to the surface. There is usually much pain and fever, and the odor from the wound is offensive.
_Treatment._--In this form of periost.i.tis the periosteum should be freely incised, followed either by continuous irrigation or frequent injection of the wound with antiseptic solutions.
FIBROUS PERIOSt.i.tIS.--This form of the disease consists in the thickening of the outer layer of the periosteum from the inflammation reaching it from neighboring structures. This newly formed fibrous tissue may become ossified or may transmit the inflammation to the deeper bony structures. It is frequently seen in cases in which there has been an intense inflammation of the skin close to an underlying bone.
_Treatment._--The treatment should be the same as that recommended for aseptic periost.i.tis.
OSTEOMYELITIS.
This term refers to an inflammation of the bone marrow, which is most commonly seen following the bacterial infection of a compound fracture and usually results in pus formation. The bone is melted away and pus escapes from the bone under the periosteum, involving the soft tissues. It is princ.i.p.ally confined to the long bones and seldom affects more than one.
_Treatment._--The bone should be opened for the purpose of curetting out the diseased portion of the marrow cavity and removing all the necrotic pieces of bone. This should be undertaken only by a competent veterinarian.
The after-treatment consists in tamponing the wound with pledgets of iodoform gauze or a mixture of iodoform 1 part and glycerin 4 parts. The wound in the soft tissue should be kept open until the cavity in the bone has filled with granulation tissue.
RICKETS.
This disease, also called "rachitis," is an inflammatory affection of young, growing bones, and mostly involves the ribs and long bones of the legs. It consists in a failure of the organism to deposit lime salts in bone, and for this reason the bones do not ossify so rapidly as they should. The cartilaginous ends of the bones grow rapidly, but ossification does not keep pace with it. The bones become long and their ends bend at the joints, the legs become crooked, and the joints are large and irregular. All the bones affected with this disease are thicker than normal, and the gait of the animal is stiff and painful. A row of bony enlargements may be found where the ribs articulate with the cartilages connecting them with the breastbone and is called the "beaded line." A catarrhal condition of the digestive tract is usually observed. The disease may result from an inherited weakness of const.i.tution, poor hygienic surroundings, or improper diet. Calves and foals are less frequently affected with rickets than dogs and pigs.
_Treatment._--The affected animal should have nourishing feed containing a proper quant.i.ty of lime salts. Outdoor exercise and plenty of fresh air are indispensable. Limewater should be given once daily for drinking purposes and ground bone meal mixed with the food. Phosphorus, one-fortieth of a grain, and calcium phosphate, 1 dram, given twice daily to a 2-month-old calf, and proportionally increased for older animals, has proved efficacious in this disease. In some cases the long bones of the limbs are too weak at birth to support the weight of the animal, and temporary splints, carefully padded and wrapped on with some soft bandages, become necessary.
OSTEOMALACIA (CREEPS).
This is a condition of bone brittleness or softening of bone found usually in adult life. It consists in the decalcification of mature bone, with the advancing diminution of the compact portion of bone by absorption. The periosteum strips very easily from the bone. This disease is seen in milch cows during the period of heavy lactation or in the later stages of pregnancy, and the greater the yield of milk the more rapid the progress of the disease. Heifers with their first calves are frequently affected, as these animals require a considerable quant.i.ty of mineral salts for their own growth and for the nourishment of their offspring.
_Symptoms._--In marked cases there is a gradual emaciation and symptoms of gastrointestinal catarrh, with depraved appet.i.te, the animal eating manure, decayed wood, dirt, leather, etc. Muscular weakness is prominent, together with muscle tremors, which simulate chills, but are not accompanied with any rise of temperature. The animal has a stiff, laborious gait; there is pain and swelling of the joints, and constant shifting of the weight from one leg to another. The restricted movements of the joints are frequently accompanied with a crackling sound, which has caused the name of "creeps"
to be applied to the disease. The coat is dull and rough and the skin dry and hidebound. The animal is subject to frequent sprains or fracture of bones without apparent cause, as in lying down or turning around, and when such fractures occur they are difficult to unite. The bones princ.i.p.ally involved are the upper bones of the legs, the haunch bone, and the middle bones of the spinal column. The disease in this country is confined to localized areas in the Southwest, known as the "alkali districts," and in the old dairy sections of New York State. The cause of this affection is the insufficiency of lime salts in the food, also to feeding hay of low, damp pastures, kitchen slops, and potatoes, or to overstocking lands. It occurs on old, worn-out soil poor in lime salts, and has also been observed to follow a dry season.
_Treatment._--This should consist in a change of feed and the artificial feeding of lime salts, such as magnesium and sodium phosphate. Feed rich in mineral salts may be given, such as beans, cowpeas, oats, cottonseed meal, or wheat bran. Cottonseed meal is one of the best feeds for this purpose, but it should be fed carefully, as too large quant.i.ties of it are injurious to cows. Phosphorus may also be given in one-fourth grain doses twice daily, together with a tablespoonful of powdered bone meal or crude calcium phosphate at each meal. Ordinary lime dissolved in drinking water (limewater) will also be found efficacious in combating this disease, and can be provided at slight expense. A change of pasture to a locality where the disease is unknown and a free supply of common salt and bone meal will be the most convenient method of treating range cattle.
SPRAINS.
The most common accident occurring to bones and joints is a sprain of the ligaments uniting the bones, or the tendons uniting the muscles and bones.
A sprain is the result of a sudden forcing of a joint in an unnatural direction, or, if in a natural direction, beyond the power of the ligament or tendon to restrain it properly, so that part of the fibers of either are ruptured. When such an accident occurs pain is immediately inflicted, varying in degree with the extent of the injury, which is soon followed by swelling, with more or less heat and tenderness. If the seat of the injury be in any of the limbs, lameness is likely to result. Of the causes of sprain, slipping on ice or a wet floor, playing, and fighting with another animal are the most common.
SPRAIN OF THE SHOULDER JOINT.--This is liable to occur from any of the causes mentioned above or from the animal slipping suddenly into a rut or hole. When such an accident occurs, sudden lameness will attract attention.
The animal will be noticed to drag the leg when walking and to carry it in a circular direction, outward and forward, at each step. The leg should be carefully examined, pressure over the joint causing the animal to evince pain. If the person making the examination is in doubt, it is well to make a comparison between the shoulders by pressing first on one and then the other. After such an accident the animal should be tied up so as to limit so far as possible the use of the injured joint.
Soft feed should be given with a view of keeping the bowels acting freely.
_Treatment._--During the first three days the treatment should consist of cold-water irrigation to check the inflammation and relieve the pain. Hot fomentations may then be applied to hasten the absorption of the inflammatory fluids. When the pain has somewhat abated, equal parts of mercurial ointment and green soap may be rubbed into the swollen tissue.
Should lameness continue after the tenth day, good results will be obtained from the application of a blister. This may be done by carefully clipping off the hair over the joint, including a surface of 4 or 5 inches in circ.u.mference, and rubbing in the following preparation:
Powdered cantharides dram 1 Biniodid of mercury do 1 Vaseline ounce 1
The animal"s head should be carefully tied until the third day, to prevent its licking the blister. The blistered surface should then be smeared with lard or vaseline every other day until the scabs fall off. Gentle exercise should be allowed after the fourth or fifth day from the application of the blister. If the lameness still remains the blister may be repeated in three weeks or a month.
SPRAIN OF THE FETLOCK.--This may occur from misstep when the animal is moving rapidly, and the twisting or wrenching of the foot is sufficient to rupture partially the ligaments which bind the bones together at that part.
Such an accident also frequently occurs by the foot getting fastened in a hole in the floor; the wrenching is the result of the animal"s attempt to liberate it. Lameness, followed by swelling of the joint and pain when it is handled, or when the animal moves the joint, and heat, are the more noticeable symptoms. If the sprain is very severe, the animal occasionally does not bear its weight on the limb.
_Treatment._--The most important consideration in the treatment of this affection is rest, which is best enforced by keeping the animal in the stall and placing strong, muslin bandages about the inflamed joint. As in the sprain of the shoulder, cold water in the form of douches, continuous irrigation with hose or soaking tub, or finely chopped ice poultices are indicated for the first three days. Following this apply a Priessnitz bandage[2] moderately tight about the joint, which not only conduces to rest, but also favors absorption. Ma.s.sage with stimulating liniments, such as soap or camphor, may later be applied to the affected parts.
If the lameness has not disappeared by the tenth day, the blister advised for the sprain of the shoulder should be applied and the same precautions observed as to tying the animal"s head and subsequent smearing with vaseline. When a blister is applied in this locality, the back part of the heel should be first filled with lard or vaseline, and care taken to prevent any of the blistering preparation from coming in contact with the skin of that part. If this precaution is not observed, scratches may ensue and prove troublesome.
SPRAIN OF THE HIP.--This is liable to result from the animal"s slipping in such way as to spread the hind feet wide apart. The patient goes stiff in the hind legs, or lame in one hind leg, walking with a straddling gait and swinging the leg outward as it is carried forward. Tenderness may occasionally be detected on pressure, but owing to the heavy covering of muscles outside the joint this test is not always reliable.
In the acute cases give rest and cold local applications. After the fourth or fifth day the blister mentioned for sprain of the shoulder may be applied with advantage, and if this proves insufficient, as a last resort we may fire in points over the joint.
SPRAIN OF THE BACK.--Sprain of the back, particularly in the region of the loins, is not an uncommon accident among cattle. It is liable to occur from the animals slipping with both hind feet sidewise so as to twist the back, or from slipping violently backward so that great stress is thrown on the loins. The patient moves with difficulty, using the hind parts in a guarded manner, as if afraid of causing severe pain. Occasionally, if the sprain is severe, the animal will rise with difficulty. Pressure on the back in the immediate region of the loins causes pain. Such cases may be mistaken for paralysis, and, in fact, in severe cases, during the early stages of the injury, although the nerve supply is not interfered with, the injury to the muscles and resulting pain is so great that the condition is almost equal to paralysis, although liable to be attended with more favorable results.
Hot applications, such as blankets wrung out of hot water and changed often, will be likely to afford relief during the earlier stages.
Afterwards the blister mentioned for sprain of the shoulder may be applied with advantage.
FRACTURES (BROKEN BONES).