DISEASES OF THE BONES, JOINTS, AND TEETH 209 



cartilaginous tissue and the appearance of deformities in the 

 skeleton. 



Cause. — 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 more often occurs if the 

 food is of such a nature as to cause digestive disturbances and 

 interfere with absorption. The exact nature of the disease is still 

 unsettled. 



Symptoms. — In the first stages the young animal seems weak 

 and loses his appetite; the belly becomes bloated, and often an ob- 

 stinate diarrhea sets in. The most important symptom is a dis- 

 turbance in locomotion, brought about by pains and aches in the 

 bones. Affected animals step about restlessly, move stiffly and 

 with care, lie down much of the time, and resent being disturbed. 

 The bones of the limbs become enlarged at their ends, producing 

 hard, sensitive swellings at the joints. If not arrested, rickets soon 

 leads to softening of the bones. In extreme cases the bone tissue 

 is so soft it can be cut with a knife. 



Treatment. — If treatment is not given, rickets may run a chronic 

 course of several months, but spontaneous recoveries are not in- 

 frequent. As soon as the diagnosis is made the diet should be 

 regulated and good quarters and an opportunity for daily exercise 

 provided. Food rich in calcium, especially green feed, is nature's 

 remedy. In many cases lime in the form of powdered chalk (cal- 

 cium carbonate) will be found beneficial. The daily dose for foals 

 is 10 to 20 grams. Precipitated calcium phosphate should be 

 administered if the food is deficient in phosphates. 



BONE FRACTURES 



A fracture is defined as a break in a bone. Kicks, blows, and 

 falls on slippery pavements are common accidents that may result 

 in fracture. A simple fracture results from a break into but two 

 parts and the skin remains unbroken. This form is the least se- 

 rious, for healing usually takes place without infection. If the skin 

 is wounded and one of the broken ends protrudes it is termed a 

 compound fracture. This is very serious, for the protruding end 

 always becomes infected. A comminuted fracture is one where the 



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