232 SWINE PRACTICE 



losses incident to this disease. Swine should be properly housed and 

 bedding provided to prevent contact with cold damp floors. Care 

 should be exercised at farrowing time to diminish the possibility of 

 navel infection. Acute cases may be relieved temporarily or pos- 

 sibly permanently liy hot packs applied to the swollen joints. 



OSTEO-MALACIA 



Osteomalacia is a disease of mature swine characterized by a decal- 

 cification, softening and fragility of the bones. This disease is not 

 of common occurrence in swine ; however, occasional cases are en- 

 countered by practitiojiers. The disease is most common in sows 

 and is prone to occur during the lactation period and particularly 

 when the sows are being suckled by a large litter of pigs. In some 

 instances several sows on the same farm are affected with this dis- 

 ease. Osteomalacia may occur in barrows and boars, but reports 

 of such cases have not been recorded in available literature. 



Etiology. — The specific cause of osteomalacia has not been deter- 

 mined, but it appears to be a condition resulting from an insufficient 

 amount of lime in the food that is capable of being assimilated. This 

 disease may properlj^ be classed as a disease resulting from malnu- 

 trition. In instances where only one animal is aff'ected on a farm 

 where several swine are maintained, it is probable that there is some 

 anatomical or physiological defect that is the primary predisposing 

 cause of the condition. When several swine are simultaneously 

 affected on a farm the feed will usually be found deficient in lime 

 salts. 



Lesions. — The bones most frequently involved are those of the 

 extremities, ribs, vertebral column, skull, and pelvis. The affected 

 bones become enlarged and less dense, the narrow cavity of the long 

 bones is increased in size and filled with a gelatinous, usually hemor- 

 rhagic marrow, while the osseous tissue is less dense and more fragile 

 and the periosteum separates from the bone readily. Fractures are 

 very common. 



Symptoms. — The disease is usually initiated by digestive disturb- 

 iuices, which are succeeded by emaciation, impaired and usually dif- 

 ficult locomotion, fractures, and various deformities. The disease 

 finally assumes a chronic form, evidencing periods of temporary 

 improvement and relapse. This is essentially a disease of mature 

 animals, and this factor is of value in differentiating osteomalacia 

 from rickets. The prognosis is favorable in cases showing no marked 



