OSSEOUS CACHEXIA. 



11 



4. The fourth phase, or period of osteomalacia, i.e. softening of the 

 bones, is also the last. It is rarely seen in large animals like horses and 

 oxen, because accidents so often accompany the preceding stages and 

 necessitate slaughter ; but it is common in goats and pigs. 



In this phase the bones become elastic, soft and depressible, yielding 

 to the pressure of the operator's fingers. 



The flat bones are particularly liable to this change, which is common 

 to domesticated animals. The bones of the 

 head are the first to suffer ; later those of the 

 pelvis. The lower jaw becomes swollen, par- 

 ticularly about the centre of the branches 

 which may attain three, four, or five times, 

 their normal thickness. 



The depression in the submaxillary si3ace 

 disappears. The upper jaw undergoes similar 

 changes, becoming deformed and thickened 

 until the cavities of the sinuses and the 

 hollow aj^pearance of the palate are lost, while 

 the face is so changed that it cannot be 

 recognised as that of a horse, goat, etc. 



The molar teeth are almost buried, their 

 tables alone being visible at the bottom of a 

 depression, the edges of which rise above the 

 neighbouring parts (pig). 



Mastication is clearly impossible, the jaws 

 appear paralysed, the muscles powerless, and 

 only swallowing is possible, a fact which 

 explains why life is only prolonged to this stage 

 in animals which can be fed with a spoon or 

 bottle (pigs and goats). The bones of the 

 cranium, although greatty changed in texture, are always less deformed 

 than those of the face. 



The changes are such that it is often easy with a mere post-mortem 

 knife to cut the head completely in two. Osseous tissue, properly 

 so-called, has disappeared. 



All the constituent tissues, with the exception of the skin and muscles, 

 i.e., the bone, periosteum and aponeuroses, have the appearance and 

 consistence on section of the fibro-lardaceous tissue seen in chronic 

 inflammation. 



The following is a condensed description of the disease as given by 

 Law : — 



Symptoms. Poor condition or even emaciation, with very visible 

 projection of the bones. The coat is rough, skin tense^ inelastic ^nd 



Fig. 4. — Deformity of the 

 face in the horse shown 

 in Fig. 2. 



