Common Diseases of Farm Animals Part 22

1. Name and describe the different forms of inflammation.

2. Give the causes and treatment of inflammation.

3. Name and describe the different methods by which wounds heal.

4. Describe the treatment of wounds.

5. What are the causes of an abscess? Give the treatment.

6. What are the causes of fistula and poll evil? Give the treatment.

CHAPTER XXII

FRACTURES AND HARNESS INJURIES

FRACTURES.--Broken bones or fractures are not uncommon in domestic animals.

In the horse, the bones of the leg, forearm, foot, and spine are the most commonly broken. In the dog the largest percentage of fractures occurs in the superior regions of the limbs.

Fractures may be cla.s.sified as _simple_ and _compound, complete_ and _incomplete, comminuted_ or _splinter_. In the simple fracture the skin over the region escapes injury, but in the compound fracture the skin is broken and the ends of the broken bone may protrude through it. The terms complete and incomplete are used in describing fractures in which the ends of the bones are not attached to each other, or partially so. In the comminuted fracture the bone is broken into a number of pieces. There are a number of other terms that may be used in designating the different kinds of fractures, such as double, when both bones in the region are broken, and oblique, transverse and longitudinal, depending on the direction of the break.

_The causes_ of fractures may be divided into external or mechanical, and internal. Fractures may result from kicks, blows, muscular strain and contusions. Abnormal fragility due to disease, extreme youth and old age are the internal predisposing factors.

_The symptoms_ are crepitation, abnormal movement and deformity of the part. Abnormal movement of the part and inability to support weight occur in fractures of the bones of the limbs. Crepitation or a grinding, rubbing sound due to the movement of the ends of the broken bones on one another occurs when the part is moved or manipulated with the hands. Pain, swelling and injury to the skin are other local symptoms. The new tissue or bone callus is formed by the bone-forming cells in the deeper layer of the periosteum and bone-marrow.

_The prognosis is unfavorable._ The larger percentage of fractures in domestic animals are incurable, or make an unsatisfactory recovery. This is due to careless treatment, the character of the fracture and the inability to fix the ends of the broken bone. Fractures in young and small animals usually heal quickly. Individuals that are healthy and vigorous usually make a speedy recovery. Fractures heal very slowly in the aged. Compound and comminuted fractures are impossible to treat in the larger percentage of cases.

_The treatment_ consists in fixing the broken bone or bones in a normal position by means of bandages and splints. If this is not practised, the surrounding tissues become injured by the broken ends of the bone, and the fracture may become so complicated as to render treatment useless. Motion r.e.t.a.r.ds or prevents the repair of the break.

However, fractures of the ribs, pelvic bones and sometimes long bones that are well covered by heavy muscles heal naturally or in the absence of any means of retention.

_Bandaging_.--The attendant must use good judgment in devising means of fixing the broken bone, and in holding it in its natural position. Whenever possible, a plaster bandage should be used. This must not be made too heavy, and it is very necessary to adjust it properly, so that it will stay in place and not become too tight or too loose. When applied to the limb, the bandage should extend as far down as the hoof, and some distance above the break. This is necessary in order to keep it from slipping down and becoming too loose. A soft bandage should be applied first in order to equalize the pressure from the plaster cast and protect the skin. Wooden splints are not very satisfactory agents for the treatment of fractures.

Thick leather that has been made soft by soaking in warm water and then shaping it to the part makes a more satisfactory splint. In all cases a soft bandage should be applied under the splint. The adjustment of the plaster bandage or splint should be noticed daily, and whenever necessary it should be removed and readjusted. Injuries to the skin must be carefully cleaned, disinfected and bandaged before applying the plaster bandage. If evidence of wound infection occurs later, the bandage must be removed and the wound treated. Large animals suffering with a fracture of any of the bones of the limb should be placed in slings. Incomplete fracture should receive the same treatment as simple fracture. If this is practised, the danger of its becoming complete is avoided.

[Ill.u.s.tration: FIG. 61.--Shoulder abscess caused by loose-fitting harness.]

HARNESS INJURIES.--This cla.s.s of injuries is common in horses that are given steady, hard work, or that are not accustomed to work. Young horses, when first put to hard work, are especially p.r.o.ne to injuries from the collar. A large proportion of these injuries are due to an ill-fitting harness or saddle.

When the harness is not adjusted or fitted properly, there is severe pressure on certain parts. This is the common cause of shoulder abscesses (Fig. 61), sore necks and sit-fasts. Rough, uneven surfaces on the faces of the collar and saddle are the common causes of galling. The character of the work is an important factor. Work that requires the animal to support weight on the top surface of the neck is productive of sore neck. Heavy work over rough, uneven ground frequently causes shoulder abscesses and strained muscles.

The simplest and most common harness injuries are galling, sore shoulders and sore neck. Harness galls first appear as flat, painful swellings. On raising the collar from the skin the inflamed area appears dry and the surrounding hair is wet with sweat. Later, the skin becomes hard and its outer layer, and sometimes the deeper layer as well, slough, or is rubbed off by friction of the harness. The surface then appears red and moist.

Fluctuating swellings due to small collections of blood and lymph sometimes form. Sometimes, small areas on the face of the shoulder and that portion of the back pressed on by the saddle become swollen, indurated and hard and give the shoulder a rough appearance. Continuous irritation from the collar may cause an inflammatory thickening of the subcutaneous tissue in the shoulder region, and the skin appears loose and somewhat folded. This uneven surface is productive of chronic collar galls.

_A sit-fast_ is characterized by a large swelling at the top of the neck, followed by a deep sloughing of the tissues. A slightly swollen, wrinkled condition of the skin over the top of the neck is sometimes present in horses that resist the attendant, when he attempts to handle the part or harness the animal. This form of sore neck is evidently very painful, although little evidence of inflammation is present.

Strain of shoulder muscles and shoulder abscesses have been discussed under their separate heads.

_The treatment is very largely preventive_. Too little attention is given to the proper fitting of the harness and saddle. A well-fitted collar that properly distributes the weight on the shoulder, and is neither too small or too large at the top of the neck, is the best preventive for shoulder and neck injuries. Old, ill-fitting, lumpy collars should not be used.

Neither should the same collar be used for different horses. Farmers should avoid using sweat pads that are lumpy or soaked with sweat. If soft and dry, such pads are useful in preventing galling. The surfaces of the collar or saddle that come in contact with the skin should be kept smooth and clean. In the spring of the year, it is advisable to bathe the shoulders of work horses with cold water twice a day. Bathing the shoulders with the following preparation is a useful preventive measure: lead acetate four ounces, zinc sulfate three ounces and water one gallon. Smooth leather pads for the top of the collar and saddle are useful preventive and curative agents.

_Galls are lest treated by rest_. Ointments or "gall cures" are usually applied. The following dry dressing dusted over the red, moist, abraded surfaces is quite healing: tannic acid one ounce, boric acid four ounces, and calomel two ounces. This may be dusted over the part two or three times daily. Dry, abraded surfaces may be treated by applying a mixture of glycerine four ounces, tannic acid one-half ounce and carbolic acid one dram. In operating for the removal of fibrous enlargements, thickened skin and abscesses on the front of the shoulder, it is advisable to make the incision in the skin well to the side of the face of the shoulder in order to avoid scarring the surface that comes in contact with the collar.

QUESTIONS

1. Name and describe the different kinds of fractures.

2. What are the symptoms of fracture?

3. Describe the treatment of fractures.

4. What are the causes of harness injuries?

5. Describe the treatment of the different harness injuries.

CHAPTER XXIII

COMMON SURGICAL OPERATIONS

DEHORNING CATTLE.--It is very often necessary to remove the horns of cattle in order to prevent their injuring or worrying certain individuals in the herd. This operation is of greatest economic importance in dairy and feeding cattle. When first practised, the dehorning of mature cattle was condemned by some persons who deemed it an inhuman and unnecessary operation. It is surely a humane act to remove the horns of cattle that are confined in small yards and pastures, and prevent them from painfully, or seriously, injuring one another.

In most localities there are men who are well equipped to dehorn cattle, and able to perform this operation for a very moderate fee. It is not advisable to attempt to dehorn a number of adult cattle if the operator is not well equipped for the work. Unless a well-constructed dehorning rack is available for confining the animals, there is danger of injuring them and it is very difficult to saw off the horn quickly and satisfactorily. This increases the pain that the animal suffers, and horn stubs soon develop.

Good equipment, such as a chute, saw or clippers, is necessary. A dehorning chute should be built of plank with a good frame well bolted together, with stanchion and nose block for confining the head. Most operators prefer a meat saw for cutting off the horns. It is preferable to dehorning shears, as there is danger of fracturing the frontal bone when removing the horns of mature cattle. The best form of dehorning shears have a wide V in the cutting edge.

_The operation is very simple_. The horn should be cut off at a point from one-quarter to one-half an inch below the hair line or skin. If this is not practised, an irregular horn growth or stub of horn develops. It is usually unnecessary to apply anything to the wound. If the animal does not strike or rub the part, the clot that forms closes the blood-vessels and the haemorrhage stops. In case of haemorrhage of a serious nature, a small piece of absorbent cotton may be spread over the surface of the wound, and pushed in to the opening in order to keep it in place. Pine tar may be smeared over this dressing. Some operators prefer cauterizing the wound with a red-hot iron for the purpose of preventing haemorrhage. During warm weather, the wound should be washed daily with a two per cent water solution of a coal tar disinfectant, until healing is well advanced. A very necessary after-treatment is the washing of the part after two or three days for the purpose of removing the dried blood.

The opening at the base of the horn communicates directly with the frontal sinus, a large cavity situated between the two plates of the frontal bone.

Sometimes the bone is slivered, or the wound becomes infected and inflamed.

This may be due to a dirty dehorning saw, or getting dirt into the wound.

The inflammation may extend to the sinus and a heavy discharge from the cavity occur. This complication may be prevented by placing the saw or cutters in a disinfectant when not in use, and cleaning and disinfecting the wound very carefully for a few days after the operation.

_The horn b.u.t.tons of calves_ from a few days to one week of age can be destroyed, and the growth of the horn prevented by applying caustic soda or potash to them. The method of procedure is as follows: Clip away the hair from around the base of the horn tissue and apply a little vaseline to the skin near, but not close to, the base of the horn; moisten the horn b.u.t.ton and rub it two or three times with the end of the stick of caustic; do not allow the calf to go out in the rain for a few days after applying the caustic. The horns of calves a few weeks of age may be removed with a sharp knife or calf dehorner.

CHOKING.--This is a common accident in cattle and horses. The object that causes the choke may be lodged in the pharynx or oesophagus. Certain individuals are more p.r.o.ne to choke while feeding than others. This is because of their habit of eating greedily, and swallowing hastily without properly mixing the bolus with the saliva. For this reason, choking occurs when the animal is eating dry feed. Cattle frequently become choked on pieces of such food as roots and apples that are too large to readily pa.s.s down the oesophagus. Sharp objects taken in with the food sometimes become lodged in the oesophagus or pharynx.

_The symptoms_ differ in complete and partial choke. In the latter, the symptoms are not very characteristic. The animal may stop feeding, but shows very little evidence of suffering pain. It may be able to swallow a little water. On attempting to drink, a part of the water may be returned through the nose, the same as in complete choke. Ineffectual efforts to swallow, salivation, coughing, hurried respiration, and an anxious expression of the face occur in complete choke. Bloating may complicate this accident in ruminants. After partial choke has persisted for a day or two, the animal appears dejected or distressed. Pressure on the trachea by hard objects may cause difficult respiration.

Mechanical pneumonia sometimes occurs. This is due to the food and water that the animal may attempt to swallow, being returned to the pharynx and pa.s.sed into the air pa.s.sages and lungs.

_The treatment_ is as follows: Animals that have choked should not be given access to feed of any kind. Any attempt to take food or drink water may result in pneumonia. It may be necessary to drench the animal with a very small quant.i.ty of water for the purpose of diagnosis. The most common form of choke in horses is that due to acc.u.mulation of dry food in the oesophagus. The administration of a drug that stimulates the secretion of saliva is a very successful method of relieving this form of choke.

Pilocarpine is the drug commonly used. Cheap whips should not be introduced into the oesophagus for the purpose of dislodging the foreign body. There is always danger of the whip becoming broken off, and the broken part lodging in the oesophagus. Neither should such rigid objects as a broom or rake handle be introduced, because of the danger from serious injury to the walls of the pharynx and oesophagus. The flexible probang, which is usually made of spiral wire covered with leather, is a very useful instrument to relieve choke when in the hands of an experienced operator. If the object causing the choke is situated in the neck portion of the oesophagus, it may sometimes be moved forward, or toward the stomach by pressure with the fingers.