Fig. 280.—Perforating tuberculosis of the right frontal region.

Tuberculosis of joints produces special symptoms resembling those seen in the “white swellings” of man, that is, diffuse, œdematous, warm and moderately painful swelling of adjacent parts, accompanied by lameness of varying intensity. According to Guillebeau and Hess, many conditions described as strain or rheumatic arthritis are really tuberculous in character. They may remain stationary for a long time, or even recede under treatment. As a rule, however, these forms of tuberculous arthritis assume the fungoid type and prove incurable.

They are clinically distinguished from ordinary arthritis by the enormous swelling, which involves the extremities and a portion of the shafts of the bones. The adjacent muscles are chronically contracted, and the diseased joint is held semi-flexed. In course of time, if the patients are kept alive, abscess formation may occur, but this is seldom seen in practice, because the animals are slaughtered.

TUBERCULOSIS OF THE BRAIN.

Tuberculosis of the nervous centres, localised either in the meninges or the brain proper, may attack both young and old animals, not as a primary condition, but as a sequel to visceral disease, which, however, may have produced no outward indications, a fact that renders the diagnosis extremely difficult.

When localised in the meninges, the disease produces the symptoms of ordinary meningitis, general weakness, vacillating, staggering or irregular gait, disturbed vision, variation in the size of the pupils, difficulty in swallowing, muscular twitching, cramp of the muscles along the upper margin of the neck, etc.

Tuberculosis of the brain proper seems more commonly to affect the anterior convolutions and the depths of the frontal and temporal lobes. It produces some of the symptoms of meningitis or symptoms suggestive of the existence of cœnurosis, as, for instance, walking in circles, lameness of central origin, without appreciable lesions of the limbs, prolonged kneeling, disturbed vision, generalised attacks of epilepsy or of Jackson’s epilepsy, spasm of the pharynx, general signs of compression of the brain or cerebral dropsy, dulness, coma, etc.

Fig. 281.—Tuberculosis of the brain. 1, 2 and 3, Tuberculous centres.