The Osseous System 343 



with more or less arrest of development of the whole body. The 

 ill-formed bone is produced principally in the epiphysial region of 

 long bones, and the sutures of the cranial bones, which in new-bom 

 healthy dogs are well closed, are usually large in rachitic dogs. 

 The disease has been ascribed to malnutrition, particularly to food 

 lacking lime salts, to digestive disturbances, and also to hereditary 

 taint. It is highly probable that hereditary or congenital influences 

 play a part in its production, through insufficiency of the th)rmus 

 gland, in view of the symptoms following experimental ablation of 

 the gland practiced recently by Mendel. Dogs of the larger breeds 

 (Great Danes, St. Bernards) are most often affected, principally 

 between the ages of three and six months. It is important, how- 

 ever, not to confound with rickets a condition also seen in the young 

 of the larger breeds, where, owing to the weight of the body the 

 legs have to support before they are completely ossified, the latter 

 become bent and misshapen. 



Symptoms and Diagnosis. A dog affected with rickets ex- 

 hibits a general disturbance of the system — indigestion, inappetence, 

 weakness and lethargy. In a little while the typical bone lesions 

 develop. In the long bones the epiphyses become greatly enlarged 

 and the shaft curved. In advanced cases the inferior extremities 

 give way, causing the knee and hock to come in contact with the 

 ground, the vertebral column becomes curved, the thorax sinks in, 

 and the libs exhibit nodosities. The facial bones also show de- 

 formity. Sometimes the affected animal is unable to stand and 

 experiences considerable pain at the slightest movement. The dis- 

 tortion may involve the pelvic bones to such extent as to prevent 

 fetal delivery (Reichenbach). 



Treatment. Practically nothing can be done in a surgical way 

 to remedy rickets, the treatment being altogether medicinal. The 

 diet must be stimulating and consist largely of meat, shaved green 

 bone, milk, etc. Of medicaments, cod liver oil, lime water, and the 

 official syrup of phosphate of lime are highly recommended. Treat- 

 ment on similar lines is indicated for simple crooked development, 

 but in the latter case the more the animal is confined and encouraged 

 to rest the better. 



OSTEOMALACIA. 



This disease, somewhat similar in its nature to rachitis, is char- 

 acterized by softening of the bones through resorption of their 



