Symptoms. Infectious rheumatism in young animals assumes one of two clinical appearances, possibly due to different causes, viz.—plastic or suppurative arthritis following umbilical infection, and simple exudative arthritis. In the former variety symptoms appear soon after birth, rarely after the age of two months, and as an exception in animals of six to eight months affected with rachitis. The onset is sometimes sudden; the patient, though healthy on the previous evening, is unable next morning to rise or move. Hence in France this disease has received the titles, amongst others, of laminitis and paralysis of the newly born.
Certain joints, often a pair, appear swollen, hot and painful. The synovial sacs are distended, and in the upper joints of the limb appear much more prominent than in the lower. When the patients are still able to move they walk on three legs, but usually they remain lying permanently, and if aroused show great difficulty in rising and very acute pain in moving.
Fig. 50.—Young bull suffering from infectious rheumatism.
Fig. 51.—Attitude when walking of a calf suffering from infectious rheumatism.
General disturbance is also very marked; the temperature varies between 103° and 105° Fahr. The animals are dull, have no appetite, and exhibit intense thirst. The pulse rate and respirations are increased, and not uncommonly symptoms of grave visceral complications, such as endocarditis, pleurisy, pneumonia, etc., can be detected. Diarrhœic enteritis sometimes appears as a secondary development.
The animals remain permanently lying down. They can only be induced to rise with difficulty, and, when moved, exhibit very acute pain.
In many cases the disease then takes a rapid course and ends fatally. Death is the usual termination whenever any of the above-mentioned visceral complications exist. Recovery is exceptional. In certain lucky cases, sometimes without any treatment whatever, the symptoms become less acute, the appetite persists or improves, fever diminishes, the condition of the joints remains stationary, and after the lapse of several weeks there is ground for anticipating recovery. In all cases, however, the convalescents remain thin and sickly, exhibit pain and capricious appetite, and in very few cases indeed is there any economic reason for keeping them alive.
More frequently infectious rheumatism terminates by abscess formation in the joints. The articular cavity becomes filled with pus, the tissues covering one of the synovial sacs soften, and the abscess opens, discharging fibrinous clots, thin watery pus mixed with synovia, and débris of articular cartilages or ligaments. Pyæmia is the final complication when the patients are not slaughtered.