ACTrNOMYC(.)SI,S OF TPIE MAXILLA. 



673 



it more frequently attacks some parts of the body than others, and 

 by far the greater number of cases occur in the ox. 



ACTINOMYCOSIS OF THE MAXILLA. 



Actinomycosis of the maxilla attacks young animals, and its usual 

 seat is in the molar region, although occasionally it affects the incisors. 

 The earliest symptoms consist in swelling of the bone, which may 

 be overlooked if within the mouth, but the outline of the jaw soon 

 becomes deformed, generally in the middle region of the row of molars. 

 Somewhat tender and firm to the touch at first, the tumour gradually 

 increases in size, invades the 

 deeper regions of the skin, 

 and displays fluctuation at 

 one or two points, followed 

 by abscess formation. The 

 pus discharged may be white, 

 creamy, and inoffensive, but 

 the cavity of the abscess 

 shows no tendency to cica- 

 trise, and the opening through 

 which the pus has escaped is 

 transformed into a fistula. 

 From this moment the pus dis- 

 charge is of a greyish, sanious 

 nature, and contains a greater 



or less number of little yellowish grains. It soon acquires an offen- 

 sive odour, and the fistulous opening is surrounded by exuberant granu- 

 lations, forming a fungoid mass. 



The neighbouring tissues become hardened and lose their sensitive- 

 ness, the jaw becomes completely deformed, and a condition is set up 

 which the old writers considered as true cancer of the jaw or maxillary 

 osteosarcoma (Fig. 268). 



A probe passed into the fistula penetrates deeply, usually into the 

 thickness of the jaw itself, and however carefully manipulated injures 

 the diseased tissues and causes free bleeding. 



If neglected, these lesions become steadily worse, mastication is more 

 difficult, being possible only on the healthy side, and the animals lose 

 condition and eventually die of exhaustion. The external lesion, repre- 

 sented by the fungoid mass, increases in size, assumes a blackish colour, 

 and discharges an offensive liquid. Portions of it undergo mortifica- 

 tion and give off a characteristic and extremely foetid odour. The 

 molars become loose and in some cases fall out, but development is 



D.C. ^ ^ 



Fig. 268. — Actinomycosis of the jaw. 



