The Farmer's Veterinarian: A Practical Treatise on the Diseases of Farm Stock

by Charles William Burkett

LOCKJAW.

—This disease, very frequently called tetanus, is an infectious disease in which the body muscles are spasmodically contracted or stiffened. The muscles that move the jaw are frequently affected and the animal is unable to open the mouth. Because of this condition the disease is commonly known as lockjaw.

The spread of the disease does not occur through healthy animals coming in contact with animals having tetanus, but by inoculation. The germ of tetanus is present in the soil, manure and dust. It enters the body by way of wounds, especially punctured and bruised wounds. The injury may result from stepping on a nail, and the germs are planted in the deeper structures of the foot. Such a wound usually has poor drainage, the horn of the hoof closing the mouth or opening. Here the germs grow and produce a poisonous toxin that is said to be the most powerful produced by any bacteria. This toxin acts on the nerve centers of the brain and spinal cord, causing extensive spasmodic contraction of the body muscles.

Tetanus sometimes occurs in the absence of any noticeable wound. It may be in such cases that the seat of the infection is a slight abrasion of the skin, or the lining membranes of the respiratory and digestive tracts. The tetanus bacillus is a slender, spore-producing bacterium. The spore is located at one end of the rod in the form of a round head, that gives the organism a pin shape, hence the name of pin bacillus. It is very resistant to outside conditions and the action of the chemical disinfectants. It is because of its ability to resist the action of disinfectants and the fact that it develops best when protected or covered by the tissues and wound secretions, that this disease so often follows ordinary wound treatment.

LOCKJAW

Note the rigid, tense position of the muscles.

From a few days to several weeks may lapse from the time of infection with the germs until the development of the stiffness and spasms. Sometimes the wound by which the organism has entered the tissues has healed before the symptoms of tetanus are manifested. In case the symptoms develop a few days after the inoculation the disease is severe or acute in form, and less violent or subacute if the symptoms are manifested after the second week. The above statement does not hold true in all cases, but it may be considered true in a general way.

Of the domestic animals the horse is the most commonly affected. The symptoms shown by this animal are very characteristic. Any person that has had the opportunity to see and examine a horse suffering from tetanus should have no trouble in recognizing the disease in other animals.

The Characteristic Symptom

is the spasmodic contraction of the muscles. This may vary in the different individuals, depending on the susceptibility of the animal and the quantity of poisonous toxin present in the system. There is at first a slight stiffness of the muscles of the back, neck, head, and limbs, and the animal is more nervous than common. A noise in the stable or a slap with the hand may increase the stiffness and contractions temporarily. The contracted condition of the muscles of the eye, are, perhaps, the most noticeable early in the disease. These muscles pull the eyeball backwards, the fatty cushion is pressed on and the third eyelid protrudes, covering at times from one-third to two-thirds of the front part of the eye. In the severe form of the disease the muscles feel hard, especially those of the back and neck, and the animal moves with difficulty. In addition to the muscular symptoms, the respiration and pulse beats are quickened and the body temperature higher than normal. The evidence of suffering from the contracted condition of the muscles is very marked, and, unless supported in some way, the animal may fall to the floor. If the symptoms develop a few days after infection, the animal usually dies. The acute form is very fatal, but in the mild or subacute form the chance for making a recovery is good.

Tetanus Is a Preventable Disease.

It may be largely prevented by the careful disinfection of wounds, and the use of anti-tetanic serum. In most localities the proper treatment of the wound is a sufficient preventive measure, but in localities and stables where the disease is common the anti-tetanic serum should be used. Ordinary cleansing of a wound, as practiced by most stockmen, is not sufficient to destroy the bacillus of tetanus. The wound must be carefully cleaned, disinfected and prepared for healing. This should be kept in mind when treating a wound, and instead of using an agent that we know little about, we should secure reliable information regarding the different commercial disinfectants and methods of caring for wounds. That class known as tar disinfectants is most commonly used. The better grade belonging to this class should be used.

If anti-tetanic serum is used, it should be injected as soon after the injury has occurred as possible. The injection is made hypodermically, usually beneath the skin on the side of the neck. Large doses of anti-tetanic serum given after the symptoms have developed may assist recovery. However, in the severe form of the disease this treatment is uncertain.

When the animal comes down with the disease, it should be made as comfortable as possible. The quarters should be roomy, quiet, clean, and well ventilated. It is advisable to support the horse with a sling unless the animal is worried or made nervous by it. This prevents his becoming tired and falling down. We should give the animal the best of care in the way of regulating the diet, etc., but should avoid annoying it by our attention. Medicinal treatment is of little benefit and should be given a secondary place. In fact, dosing the animal with medicine, especially if large doses are given, may do more harm than good in the treatment of this disease.