ARTICULAR RHEUMATISM. 91 



fortimafcely such complications are far from being constant. Auscultation 

 and percussion sometimes reveal the lesions of pleuris}^ endocarditis, 

 pericarditis, etc. 



The development of articular rheumatism varies greatly, and may 

 occasionally continue for ^Yeeks or months, the condition of one joint 

 improving only to be followed by inflammation of another. 



The visceral lesions rarely disappear completely', and it is not un- 

 common to note sj'mptoms of chronic valvular endocarditis. Eelapses 

 are somewhat frequent, and the disease may continue in a chronic form 

 after the acute symptoms have disappeared. 



Lesions. The joint itself is not alone affected. All the tissues sur- 

 rounding it are congested, swollen and painful, particularly the sheaths 

 and insertions of the tendons. Within the inflamed synovial capsules 

 of the joints an increased quantity of turbid synovia accumulates, dis- 

 tending the joint and producing a condition of hydrarthrosis. 



In animals slaughtered during the course of the disease one finds 

 congestive infiltration of the limbs. 



The temperature of the parts near the affected joints is higher than 

 that of neighbouring regions. Sensibility is much more acute, and the 

 slightest external pressure gives rise to pain. 



In favourable cases the joint may appear scarcely injured. The 

 principal symptoms are those of pain. In old-standing cases certain 

 l^ermanent changes may occur, such as thickening and hardening of the 

 wall of the synovial capsule, fibrous infiltration of the tissues around the 

 joint, or even diffuse and irregular calcareous infiltration. 



Cases of false or true anchylosis are rare, the animals usually being 

 slaughtered before such conditions can develop. 



Complications. The commonest complications are endocarditis and 

 pericarditis. Valvular endocarditis localised in the auriculo-ventricular 

 valves is revealed by a systolic sound, and by tumultuous or irregular 

 beating of the heart when the animals are forced to move. Pericarditis, 

 which seems rare in bovine animals, is much commoner in sheep. This 

 pericarditis, however, produces none of the external signs of pericarditis 

 due to a foreign body. Like tuberculous pericarditis, it is only accom- 

 panied by a trifling amount of exudate, and is recognised by increased 

 cardiac dulness and diminution in the cardiac sounds on auscultation. 



Simple pleurisy associated with pericarditis is frequent in sheep, but 

 unknown or little known in the ox. 



If in animals other visceral complications occur, affecting the peri- 

 toneum, meninges of the ])rain or intestines, they are at present little 

 recognised. 



Diagnosis. Articular rheumatism can only be confused with osseous 

 cachexia or laminitis. Osseous cachexia, however, possesses symptoms 



