Text book of veterinary medicine, Volume 2 (of 5)

by James Law

Symptoms. These vary with the particular poison: With mouldy bread the symptoms may come on promptly with indigestion, tympany, constipation, marked irritation of the urinary organs, and it may be nervous disorder. Sometimes, as noted above, the narcotic action is shown with paresis or paralysis and stupor without any manifest disorder on the part of the digestive or urinary functions.

Most commonly with mouldy fodders, grains, marc, or ensilage the results are tardily developed and only after long continued use of the spoiled food. There is then loss of appetite, and rumination, drivelling of saliva, some tympany, and abdominal pain shown by frequent movement of the hind limbs, lying down and rising. The bowels may be costive at first, but this early gives place to a fœtid diarrhœa, with weak rapid pulse (100 per minute) palpitations and hurried breathing. The walk becomes weak, unsteady, staggering or stumbling, and there may appear marked paresis especially of the hind parts. When nervous excitement sets in there may be twitching of the muscles of the neck, shoulders or thigh; the eye rolls or becomes fixed and the pupils are dilated; the muscles of the face are contracted and the jaws clinched, with grinding of the teeth. Bellowing or pushing of the teeth and nose, the forehead or horns against the wall or other obstacles, or the dashing violently against obstacles is occasionally observed, and indicates in most cases an unfavorable termination.

The duration of the malady is uncertain. It may not be over five or six hours in acute cerebral cases, and especially in sheep, and again it may be prolonged for one or two weeks. Death often takes place in convulsions.

In gangrenous ergotism a necrotic sore with more or less surrounding swelling may be seen, and a line of demarcation forms of a pink or purplish aspect along which the separation of the dead tissue takes place. The slough is usually of a dark red or black color, the red globules having apparently migrated into the tissues and piled up in the capillaries in the early stages of stagnation. When the line of separation is higher, the line of demarcation completely encircles the limb, the inflammation and swelling is very marked just above this line, the skin and soft tissues beneath drying and withering up into a dark red leathery mass, and this is gradually separated by the formation of a granulating surface above. The process of separation takes place much more slowly through the bony tissues, and not unfrequently the soft tissues having become detached, the lower part of the limb is separated at the first joint below the line of demarcation and the bone from that line down to its free end remains as a projecting necrosed stump. In the ear or tail the necrotic portion withers up into a stiff rigid shrunken slough which becomes detached sooner or later by mechanical violence.

In the nervous ergotism the symptoms are largely those of the adynamia, paresis and convulsions already described.

In abortion from ergotism there are usually few premonitory symptoms, and the occurrence is to be explained by the number of victims in a herd eating ergot or smut.

Lesions. These vary greatly. Usually the congestion and inflammation are most prominent in the abomasum and small intestine, complicated by ecchymosis and even extravasation which may so thicken the mucosa as to block the intestine (Walley). The mesenteric glands are usually gorged with blood and of a deep red. The brain may be nearly normal or violently congested and with its meninges covered with petechiæ.

Diagnosis. From anthrax this affection is distinguished by the absence of the specific large bacillus in the blood and of the marked enlargement of the spleen, by the great prominence of the nervous symptoms in many cases, and by the history of a dietetic cause.

From the coccidian hemorrhagic dysentery it is diagnosed by the absence of the coccidia in the stools and the predominance of the nervous systems.

From foot and mouth disease, the gangrenous ergotism is distinguished by the facts that the sores are in the nature of sloughs, and not vesicles, and that some members of the herd are almost certain to show sloughing of the limb at some distance above the hoof. More important still is the fact that the daintily feeding sheep and the pig kept in the same yards do not suffer from the ergotism.