292 DISEASES OF CATTLE. 



from place to place. The parts usually affected are the fibrous struc- 

 tures of the joints, tendons, ligaments, and muscles. The serous 

 membranes and heart may also be affected. According to its loca- 

 tion, rheumatism is specified as articular or muscular. According 

 to its course, it is designated as acute or chronic. 



Cause. — Among the factors which are actively causative of rheuma- 

 tism may be mentioned exposure to dampness and cold, especially 

 while the animal is perspiring or fatigued after severe physical exer- 

 tion. Among other causes often mentioned are acidity of the blood, 

 nervous derangement, microbes, and injuries. It occasionally follows 

 another disease, such as pleurisy. The influence of age and heredity 

 may be considered as secondary or predisposing causes. Sometimes 

 the disease appears without any apparent cause. On the whole, it 

 may be said that any of the above-mentioned factors may have more 

 or less influence on the production of rheumatism, but the specific 

 cause is as yet unknown. 



SymptoTTi^ of articular rheumatism. — The symptoms appear sud- 

 denly and with varying degrees of severity. The animal presents a 

 downcast appearance, with staring coat, horns and ears cold, and the 

 mouth and muzzle hot and dry. Appetite and rumination may be 

 impaired and followed later or be accompanied at the same time by 

 constipation. Constipation may be followed by impaction of the 

 stomach or bowels. Thirst is increased, but the amount of urine 

 voided is scanty. Respiration and pulse are accelerated, and there is 

 usually a fever, rising sometimes as high as 108° F. The animal pre- 

 fers to lie down, and when forced to rise stands with its back arched. 

 The movements are stiff and lame and cause great pain. The disease 

 may attack one or more joints at the same time: in fact, it is often 

 symmetrical. One joint may improve while another becomes af- 

 fected, thus showing the shifting tendency of the inflammation. The 

 affected joints, including their tendons, ligaments, and synovial mem- 

 branes, may be swollen, hot, and distended with liquid. They are 

 very tender, and, if treated carelessly or injured, may become in- 

 fected, thus leading to suppuration. AATiile rheumatism attacks per- 

 haps more frequently the knees and fetlocks, it has no special affinity 

 for any joint and ma}^ attack the stifle, hip, shoulder, or elbow joint. 

 In mild cases of articular rheumatism, the animal may fully recover 

 in a few days. 



In chronic articular rheumatism there is less tendency of the dis- 

 ease to shift about, but there is a greater liability of structural change 

 in the affected joints. This change may consist of induration, exos- 

 tosis, or even anchylosis. These structural changes about the joints 

 may lead to permanent deformity, such as bending of the neck. 

 Fever is not so constant in the chronic form as in the acute, and the 

 latter may lapse into the former. 



