CHARACTER OF THE DISEASE.
Mycotic stomatitis is a sporadic, or noninfectious, disease which affects cattle of all ages that are on pasture, but more especially milch cows. It is characterized by inflammation and ulceration of the mucous membrane of the mouth, producing salivation and inappetence, and secondarily affecting the feet, which become sore and swollen. Superficial erosions of the skin, particularly of the muzzle and of the teats and udders of cows, may also be present, with some elevation of temperature and emaciation.
CAUSE.
This disease, as its name indicates, results from the eating of forage containing fungi or molds. It is probable that more than one fungus is involved in the production of this disease, but no particular species has been definitely proved to be the causative factor. Several attempts have been made by the writer to determine the exact cause and also to transmit the disease to other animals by direct inoculation, but with negative results. Suspicion, however, has been directed by various observers to the Uromyces and the red and black rusts that occur on clovers. These fungi cause very severe irritation of the lining membrane of the mouth, producing sometimes a catarrhal, at other times an aphthous, and occasionally an ulcerous stomatitis. The fungus of rape, etc. (Polydesmus excitiosus), is very irritating to the mouths and feet of cattle, causing severe inflammation and in some instances producing symptoms that have been mistaken for foot-and-mouth disease. The fungi (Penicillium and Puccinia) found on grasses have also been credited with the production of stomatitis. The fact that this disease disappears from a locality at a certain time and reappears at irregular intervals would suggest the probability that certain climatic conditions were essential for the propagation of the causative fungi, since it is well known that the malady becomes prevalent after a hot, dry period has been followed by rain, thus furnishing the requirements necessary for the luxuriant development of molds and fungi. Owing to this fact the disease is observed in one locality during one season and in an entirely different section another year, but reappears in the former center when favorable conditions prevail. In this way the affection has occurred at irregular intervals in certain sections of both the United States and Canada.
SYMPTOMS AND LESIONS.
Among the first symptoms observed in mycotic stomatitis are inability to eat, suspension of rumination, frequent movements of the lips with the formation of froth on their margins, and in some cases a dribbling of saliva from the mouth. There is a desire to eat, and frequent attempts to take food are made, but prehension is very difficult. If, however, feed is placed on the back of the tongue, it is readily masticated and swallowed. If the mouth is examined at this time, it will be found red and hot, and exceptionally small blisters will be seen, which, however, quickly become eroded and develop into active ulcers varying in size from one-eighth to 1 inch in diameter. Where several ulcers have coalesced a large and irregularly indented patch is formed. These erosions are most frequently found on the gums around the incisor teeth, on the dental pad, inside the lips, and on the tip of the tongue, but they also occur on the cheeks, interdental space, and dorsum of the tongue. The ulcers have a hemorrhagic border, a depressed suppurating surface, and contain a brownish or yellowish colored débris, which is soon replaced by granulation tissue. As a result of this sloughing of the tissues and the retention of food in the mouth, a very offensive odor is exhaled. The muzzle becomes dry and parched in appearance, which condition is shortly followed by erosions and exfoliations of the superficial layer of the skin. Adherent brownish crusts and scabs form over the parts, and similar lesions are seen around the nostrils and external surface of the lips.
In some cases there are associated with these alterations a slight swelling and painfulness in the region of the pasterns, at times affecting the forefeet, at other times the hind feet, and occasionally all four feet. In a few cases the swelling may extend above the fetlock, but it has never been observed above the knee or hock. The skin around the coronet may occasionally become fissured and the thin skin in the cleft of the foot eroded and suppurated, but without the formation of vesicles. As a result of these feet lesions, the affected animal may assume a position with its back arched and the limbs propped under the body as in a case of founder, and will manifest much pain and lameness in walking. If it lies down, the animal shows reluctance in getting up, and although manifesting no inclination to move about, when forced to do so there is more or less stiffness and a tendency to kick or shake the foot as if to dislodge a foreign body from between the claws.
In some outbreaks the milch cows have slight superficial erosions on the teats which at times extend to the udder. The cracks in the skin are filled with serum and form brownish-colored scabs. The teats become tender and the milk secretion diminishes; in some cases it disappears. A similar tendency toward the formation of fissures and scabs on the skin of the neck and shoulders has manifested itself in a recent outbreak in Texas, and this feature was likewise noticeable in the disease when it occurred in Maryland and Virginia in 1889.
In mild cases only the mouth lesions may be observed, or these alterations may be associated with one or more of the other above-described symptoms, but in severe cases, where there is a generalized mycotic intoxication, one animal may show all these alterations. When the disease is well developed the general appearance of the animal is one of great lassitude, and it either stands off by itself with hind feet drawn under the body and its forefeet extended, or it assumes a recumbent position. Owing to the inability to eat and to the general systemic disturbance present, the animal loses flesh very rapidly and becomes greatly emaciated in the latter stages of the disease. The temperature and pulse are somewhat increased, the former 2 or 3 degrees, the latter to from 75 to 90 beats per minute. The fever is not lasting, and these symptoms are soon modified. The animal has an anxious look, and in a few cases there is a gastrointestinal irritation, the feces being thin, of a dark color, and of an offensive odor.