INFLAMMATION OF THE SHEATH.
This condition is much more common in the ox than in the horse on account of the different anatomical structure of the parts, and the methods of keeping and using oxen.
Causation. Several predisposing causes undoubtedly exist. The sheath is prolonged beneath the abdomen to a considerable distance beyond the glans. It is narrow, deeply seated, and, during micturition, not even the point of the penis passes beyond it. The urine, therefore, soils the interior, or a certain quantity may be retained, according to whether the orifice is more or less obstructed by urinary sediment, sebaceous material, manure, or other material. Moreover, experience shows that of all the large ruminants, those used for outdoor work are the most affected.
Of the occasional causes, if we except sebaceous and urinary products, the most important is mechanical violence, such as the lacerations or wounds produced by the bed-piece of the trevis when the animal is being shod. The working ox throws its whole weight on this bed-piece, on which it lies on one side or the other, according to the foot which is being lifted. The sheath is compressed, and if the animal is heavy and struggles, the parts may be abraded and torn, or the sheath and even the glans may be crushed. In less dangerous cases the connective tissue may be lacerated by the edge of the bed-piece. Any injury so inflicted is aggravated by dirt in the neighbourhood.
Symptoms. The first signs which attract attention are of a general character, and seldom very strongly marked. The animal shows slight fever, dryness of the muzzle, is restless and continually moves about, as though to get rid of the pain it feels. The hind limbs are frequently lifted. In this attitude it makes efforts to urinate, but urine is passed very slowly, and the act seems painful; then, later on, the appetite diminishes, rumination is suspended, and, as in all intense forms of cellulitis, complications may occur.
The local symptoms are more suggestive. The slowness and difficulty with which urine is passed at once attracts attention to the diseased parts. Examination immediately reveals extreme sensitiveness of the sheath, although as yet there is only slight engorgement. At a later stage a large swelling develops and extends along the abdominal wall on either side, sometimes upwards into the groin. In certain cases the sheath may be totally obstructed by sebaceous and inflammatory material, and in the absence of surgical assistance the bladder may become ruptured.
Inflammation most frequently ends in the tardy formation of an abscess, which shows little tendency to open spontaneously. It is usually accompanied by gangrene and by mortification of a mass of skin and subcutaneous tissue, sometimes of portions of the abdominal tunic. Such grave complications may even lead to the opening of an artery, and to fatal hæmorrhage.
All these symptoms develop comparatively slowly. Abscesses scarcely ever appear before the twelfth or fifteenth day, but when the disease is not treated it may continue as long as five or six months. On the other hand, resolution is the ordinary termination under suitable treatment.
Diagnosis. The diagnosis is easy when the exact facts can be ascertained. The difficulty in micturition is the chief indication. At a later stage, local swelling and acute sensitiveness are characteristic.
Prognosis. The prognosis is grave, having regard to possible complications and the chronic character which the inflammation tends to assume.