ORGANS OF LOCOMOTION 141 



Treatment. Provide proper food and surroundings, 

 and administer lime salts, as outlined in the foregoing 

 for rickets. 



Purulent Osteomyelitis 



Inflammation of the bone marrow occurs in swine. 

 This condition is sporadic, and is most frequently ob- 

 served in young animals. 



Etiology. Purulent osteomyelitis is caused by infec- 

 tion. Various pyogenic microorganisms have been identi- 

 fied, such as Staphylococcus pyogenes aureus and albus. 

 Streptococcus, and in one instance the Bacillus pyocy- 

 aneus, was isolated and apparently occurred in pure cult- 

 ure. There is probably some predisposing cause, such as 

 hog cholera, but all of the cases observed have shown no 

 lesions of cholera or other than the primary disease. 



Lesions. The ribs are most frequently affected. 

 The bone marrow becomes hyperemic and invaded with 

 leukocytes and inflammatory products, and the internal 

 pressure causes the bone to become enlarged and the 

 marrow cavity to be increased in size. The marrow and 

 the inflammatory exudate disintegrate and form pus. 

 As pus is produced the bone becomes larger and round, 

 although it may show some irregularities in shape. The 

 pus in the marrow cavity may erode the bone tissue and 

 discharge, thus producing a fistulous tract, but more 

 frequently the pus becomes caseous and may later 

 undergo calcification. Suppurative processes are rarely 

 observed in other bones. 



Symptoms. There is little outward manifestation 

 of purulent osteomyelitis other than the formation of a 

 barrel chest (the ribs form a wider arch, the thorax 

 appearing almost round in cross-section), and the promin- 

 ent tumefied ribs. If the affected animal is in good con- 

 dition the ribs are not visible. These cases are usually 

 of long standing, and the disease is essentially chronic. 

 Antemortem diagnosis is rarely made. Purulent osteo- 

 myelitis can be distinguished from osteomalacia by the 

 localization of the process in the ribs. 



Treatment. Medicinal treatment is of no value. 



