OSSEOUS TUMOUBS OSTEOID TUMOUES. 421 



Vm. OSSEOUS TUMOUKS AKD OSTEOPHYTES 



Are very irregular, of a -warty stalactic shape, and are common 

 in the neighbourhood of joints where the articular surface ia 

 affected with caries, and sometimes surround the tendons of a 

 limb when no joint disease is present. — (See Photo- lithofrraph 

 Plate I^ Fig. 4) 



They result from the ossification of an exudate which has 

 been formed in consequence of some cause of inflammation- 

 Osseous tumours are of a more compact structure than osteo- 

 phytes, and grow more from the compact structure of the bone 

 itself. Cases of great lameness sometimes occur from these new 

 formations becoming inflamed from accidental causes, and I 

 have seen necrosis of them produce sloughing of the skin, and 

 the formation of sinuses. 



IX. — OSTEOID TmrouES— osteoj:a. 

 (See Photo-lithograph, Plate I., Fig. 9.) 

 These are tumours of irregularly protuberant surface, affect- 

 ing both the upper and lower jaws of horned cattle. They are 

 generally of a slow, but sometimes of a rapid growth, and 

 when so, they possess some malignity (see Ostea-Sarcoma.) They 

 consist of a cancellous bony tissue, forming trabecule, which sur- 

 round spaces filled with a greyish white, vascular, fibrous material, 

 in which a varying quantity of cells and nuclei are imbedded. 



These tumours may vary in their density, from the presence 

 of more or less bony structure in their formation. 



If not depending upon the presence of the actinomyces, or 

 upon the irritation of the tubercular bacillus, when these tumouis 

 would be more properly classed amongst "inflammatory 

 growths," the osteoma, benign in their nature, are very rarely 

 met with in practice. The tumours of the maxillae of cattle are 

 generally evidences of actinomycosis, now said to be curable by 

 iodide of potassium given internally. 



The only treatment that can be recommended is the removal 



of the tumour at its very earliest stage, and before it has 



attained any size. If it be of any magnitude no treatment 



should be attempted, but the animal ought to be fed for 



• slaughter, if not already fit. These tumours do not seem to 



^ cause much pain or inconvenience for a long time, and hence 



^ the animal will feed well enough. 



