In the ox it may result either from mechanical injuries, suppurating sores, or surgical operations. In the cow, goat, and sheep it sometimes assumes the form of a true enzooty after parturition if the byres, etc., are not disinfected. In male animals it principally follows castration by one of the cutting methods, and in lambs is seen after amputation of the tail. A large number of animals belonging to one flock may be affected, and Moussu has known two-thirds of a given number of castrated lambs to die of tetanus.
Despite the sensitiveness of domesticated animals to tetanic infection they may all be protected, either by injections of cultures, or by gradually increasing injections of specific toxin. The latter, however, are more efficacious when modified by the addition of terchloride of iodine or of iodine water. The blood of immunised subjects rapidly acquires antitoxic powers, which may be greatly increased for the purpose of obtaining anti-tetanic serum.
The symptoms of tetanus are the same in all species.
In the first stage the animal appears stiff, walks in a jerky way and holds the head high, with the ears pricked. The eyes are slightly withdrawn into the orbits, and the animal shows marked general excitability.
In the second stage there are muscular contractions, together with trismus, stiffness of the neck, limbs and vertebral column, spasm of the spinal muscles and muscles of the limbs (tonic contraction), and the animal has a peculiar, staring look.
In the third stage mastication becomes difficult or impossible, respiration is impeded, and the animal suffers from spontaneous attacks of muscular contraction or from attacks due to external stimulation (noises, sudden movements, changes from darkness to light, etc.).
In the fourth stage the animal is liable to fall, asphyxia threatens, and death occurs from respiratory syncope.
Recovery is quite exceptional in the sheep, goat, and ox; death usually occurs between the second and sixth days.
Diagnosis. Tetanus being less common in the ox, sheep, and goat than in the horse, the diagnosis is not so easy in these animals, but as it develops under different conditions, and as it usually attacks several animals in one byre or fold, the diagnosis is rarely very difficult. At the worst some hesitation may be felt at first, the condition being mistaken for disease of the brain.
The prognosis is extremely grave.