956 



Osteomalacia, 



marrow much reddened and studded witli punctiform liemor- 

 rhages; if cachexia already exists the bone marrow is pale, 

 e-elatinous, even watery (marrow-fluid). The flat and_ short 

 bones are also brittle" or flexible; owing to the dilation of 

 the marrow spaces the spongy structure of these bones is em- 

 phasized and may contain fair-sized marrow spaces. The sound 

 of the bones is duller than that of normal bones. 



In osteomalacia of equides 

 and hogs a considerable bulg- 

 ing of the skull bones is also 

 often observed. It is less fre- 

 quent in goats and dogs. All 

 skull bones appear enlarged 

 symmetrically on both sides 

 and the periosteum is easily 

 pealed off. The surface of the 

 liones is reddened, at times 

 discolored dark- or blue-red 

 and contains numerous small 

 holes which are often con- 

 fluent ; the outer lamella of the 

 bones is soft and easily cut. 

 These changes are particu- 

 larly striking in the superior 

 maxilla which may bulge out 

 so much that the molars are 

 imbedded in the reddish, 

 rather fibrous bone mass down 

 to their masticating surfaces. 

 The weight of the macerated 

 head is usually much dimin- 

 ished (in horses 400-1160 gm., 

 as compared with the normal 

 weight of 4000 gm. [Marcone] ) ; 

 only if the bulging is excessive 

 is the normal weight main- 

 tained after maceration. The 

 bone cavities are small or en- 

 tirely obliterated. 



In consequence of atrophy 

 and softening of the bony tis- 

 sue the bones are subject to 

 all sorts of deformities. These 

 are most striking in the pelvis, the acetabula of which appear 

 pressed inward, while the ilia are much bent (Figs. 165 and 

 166) ; on the verteljral column scoliosis, kyphosis and lordosis 

 are to ))e noted and the depression of the ribs causes the thorax 

 to become narrow and tlie sterura to protrude. The pelvic 

 bones, and still more the long bones and the ribs often show 

 recent or old fractures, callus formation, and circumscribed 



Fig. 167. Osteomalacia. Superior may- 

 ilia of a f;oat 20 months old. a. periosteum 

 with numerous osteoblasts in the deeper 

 layer ; b. trabeeulae beeoniing gradually- 

 more narrow; c. narrow trabeculae sur- 

 rounded by numerous osteoblasts ; d. rem- 

 nants of trabeculae in the cellular-fibrous 

 tissue ; e. vascular cidlular-lilirous tissue ; 

 f. f,'iant cells, partially in the vicinity of 

 remnants of trabeculae. Magnif. 100. 

 After liassett. 



