This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
Actinomycosis, or lumpy-jaw, is characterized by swellings on the jaws. The swelling may be on either upper or lower jaw and may be somewhat soft at first, but soon grows hard, as the disease affects the bone. It is due to the parasite actinomysis, a vegetable fungus supposed to be on the fodder or other food and enters the animal organism through some abrasion of the skin. It sometimes affects the tongue, causing it to thicken up and become hard, in which condition it is the so-called "woody-tongue." The general health of the animal does not appear to be much affected by the disease as long as the animal can masticate its food, but after a time the jaw becomes affected to such an extent that the animal can scarcely eat, then it soon becomes emaciated. Theorists differ as to whether the flesh of such an animal is fit for food. The safest plan is to let it alone.
Treatment. - There have been many methods of treatment prescribed and some "sure cures"(?) advertised. But the only thing most of them affect, with any certainty, is the owner's pocket book. The best treatment known for this disease at the present time is that recommended by the Bureau of Animal Industry, which is as follows: Give a daily dose of iodide of potassium, allowing fifteen grains for each one hundred pounds of the animal's weight. This may be dissolved in water and given as a drench, and should be continued until symptoms of iodism are produced, which will be in from ten to fourteen days.
The animal will become languid and disinclined to move about; the appetite will fail and there will be a discharge from the eyes and nostrils. In some subjects, not all, there will be a vesicular eruption of the skin; there will be abstinence from water, and elevation of temperature. When these symptoms occur, the iodide should be withheld for a few days until the appetite returns and the other symptoms subside, when the treatment should be repeated as before. The treatment should be continued in this manner until the enlargement begins to decrease in size, which may be two or three months.