630 PRINCIPLES OF VETERINARY SURGERY 



In the superior maxilla degenerative changes of the same 

 kind are observed. The bones of the palate are also thick- 

 ened. All of the bones of the head after maceration and 

 efxposure in the air are very light. The entire horse's head, 

 excluding the teeth, often weighs but 400 grams. Occasion- 

 ally it w^eighs but 600 grams including all the teeth. A very 

 large head including all the teeth and inferior maxilla may 

 not weigh more than 1,160 grams. On the other hand there 

 are cases in which the head when greatly tumefied loses 

 but little weight. Some may weigh four kilograms, others 

 2,500 grams, and still others as high as 3,300 grams, including 

 all the teeth. The head of a sound horse of the same size 

 would weigh about 4,040 grams. The maxillary sinuses are 

 nearly closed on account of the swelling of the bones form- 

 ing their boundaries. The openings in the maxillaries are 

 more numerous and nearer to one another than in the other 

 diseased bones. On skulls which exhibit the more acute 

 rarefaction the bones forming the orbital arch, with the ex- 

 ception of the orbital process, have almost normal surfaces. 

 And the same may be said of the basilar process of the oc- 

 cipital and the squamous portion of the temporal. Even in 

 a single maxillary, every degree of the alteration may exist. 

 The symmetrical swelling of the maxillaries is the cause of 

 the facial deformity already mentioned. The sutures of the 

 bones are all quite visible, and the external foramina are 

 more numerous. 



The other bones of the skeleton are as much deteriorated 

 as those of the head, but they attract little attention because 

 they show no special deformities during life. In all long, 

 short, and flat bones the richness of the blood supply is in 

 evidence. In long bones like the tibia the marrow is exces- 

 sively red and rich in fat, and the osseous substance of the 

 diaphysis cut transversely sometimes shows a bluish tint 

 in the eccentrical zones. When the process is advanced the 



