292 PRINCIPLES OF VETEBINARY SCIENCE 



OSTEOMALACIA 



Osteomalacia is a disease of mature animals arising from 

 general nutritional disturbances and causing an increased absorp- 

 tion of lime salts from the bones. In America several outbreaks 

 have been observed among horses, especially in regions where 

 soil conditions were unfavorable and in dry years. 



Causes. — Deficiency of available lime for the organism is the 

 important causative factor. Forage grown on soil lacking in 

 phosphoric acid and lime may contain less mineral substance 

 than the animal needs. As an exclusive ration it would be 

 unsuitable. 



Symptoms. — Digestive disturbances, a run-down condition, 

 and hidebound appearance are the first symptoms noticeable. 

 Later the animal develops anemia, a depraved appetite, and diar- 

 rhea. Lameness occurs, which is usually erroneously diagnosed 

 as rheumatism. Swelling of the face, a symptom of osteoporosis 

 or "big head," a disease closely allied to osteomalacia, is seen 

 in advanced cases. The bones of the limbs are subject to enlarge- 

 ments and deformities from the deficiency in mineral matter. 



Treatment. — Osteomalacia is a chronic disease and lasts for 

 months or years. When treatment is instituted early good 

 recoveries may be looked for. The affected animals should be 

 removed to another region where soil conditions are better, or a 

 change made in their feed. If phosphorus is lacking, bean, pea, 

 or clover hays are beneficial, for they contain relatively large 

 amounts of protein. Lime salts should be added to the diet as in 

 rickets. 



RICKETS 



Rickets affects young animals only, and is due to a disturbance 

 in metabolism. It is characterized by the persistence of the 

 cartilaginous tissue and the appearance of deformities in the 

 skeleton. 



Causes. — Like osteomalacia of older animals, it is caused by a 

 deficiency in lime salts. This is substantiated by experimental 

 and direct observations, and may be demonstrated in animals 

 weaned too young and deprived of the normal supply of lime 

 previously furnished by the mother's milk. Rickets is more 

 often due to defective absorption of lime salts than to a lack of 

 them in the feed. 



Digitized by Microsoft® 



