Symptoms.—Goiter may be observed at the side of the throat, reaching the size of a fist or even larger, or it may hang down below the windpipe. In cattle the two thyroid glands are close together, and when the disease affects both there may be but one uniform swelling placed in front of the windpipe below the angle of the jaw. This swelling may be hard, soft, or doughy in consistence, and with each beat of the heart it may pulsate like an artery. It may cause labored breathing by pressure on the windpipe, and death may result from pressure on this structure, on the gullet, or on the adjoining large vessels.
Treatment.—In young animals the treatment is usually satisfactory, and consists in giving the animal a complete change of feed and plenty of exercise in the open air. If the condition appears enzootic in the district, remove the animal to another location when possible. Iodin, either in the form of ointment or the tincture, should be applied to the swelling. Injections of iodin solution, 5 grains of iodin in 1 dram of 25 per cent alcohol, may also be made into the substance of the gland. When the swelling which follows this injection has subsided it may be repeated. Potassium iodid should be given internally in 1½ dram doses twice daily for a cow, or in 20-grain doses twice a day for a calf. Extirpation of all but a small section of the swelling may be successfully accomplished by a qualified veterinarian, but if it should be entirely removed, myxedema and death follow.
FIBROMA.
Fibromas are tumors made up chiefly of connective tissue and are usually confined to the skin and subcutaneous tissue. Indurative fibromas of the skin appear as tumors of gelatinous connective tissue or as firm, white vascular connective tissue growths, which are more or less sharply outlined, move readily over the underlying tissues in company with the skin, and owe their origin to mechanical injuries, perforating wounds, repeated abrasions, or the invasion of pus cocci or botryomyces into the tissues.
These tumors in cattle are frequently found upon the dewlap as solid lumps, hard as stone to the touch, lying loosely between the layers of skin, and gradually losing themselves in the softer tissues of the neck above, or as smooth, hard tumors of glistening white substance with interlacing lines of softer tissue. They may also be found in the region of the knee or at the elbow. The skin over the growths, in accordance with the originating cause, will be found chafed, covered with scabs, or even ulcerated and accompanied with collateral edema.
These connective tissue tumors grow slowly but reach enormous size. They sometimes follow injuries to the region of the throat and form there as hard, firm growth, even reaching the size of a child's head.
A fibroma upon the larynx is not an infrequent occurrence in the ox. These tumors are always sharply outlined and have a roughened surface. They may be differentiated from actinomycotic tumors (see chapter on "Infectious diseases of cattle," [p. 358]) in the same location by their firm, fibrous structure and by the absence of pus from the interior.
A tumor is sometimes seen upon the muzzle of cattle, which assumes a diameter equaling the width of the muzzle. It is a voluminous connective-tissue formation known by the name of "fibroma diffusum."
Another form is sometimes observed upon the tongue. It grows upon a broad, spreading base, becoming very hard. It is almost lacking in blood vessels, although the few that are present are plainly in view, and in consequence is poorly supplied with fluids. It is of a smooth contour, white or whitish yellow in color, is sharply limited from the normal substance of the tongue, may be covered with mucous membrane, on which prominent papillæ are located, or only by a thin, delicate layer of epithelium, and is usually found in the middle part of the tongue, where it may reach the size of two fists.