MELANOSIS 53 



section, without subsequent cauterization of the bed of 

 the tumor, usually means a recurrence within a very short 

 time. The secondary tumor is more active than the pri- 

 mary one whenever a recurrence takes place. 



"When a melanotic tumor becomes active in a region 

 where a thorough dissection would be out of the ques-"^ 

 tion, the treatment can, of course, be only of a palliative \ 

 nature. What this would be depends upon the location of 

 the tumor and the extent to which it is hindering the 

 function of the parts involved. 



While an active melanotic tumor is a grave condition in 

 any part of the anatomy the attending veterinarian must 

 never be pessimistic in giving a prognosis. In many 

 instances these growths suddenly degenerate, discharge 

 their contents, and a spontaneous cure results. This is 

 especially true of these tumors in the anal region, and 

 also when they develop within the rectum. A rectal 

 examination should be the rule in all grey horses suffer- 

 ing from colicky pains which ca,nnot be clearly attributed 

 to acute indigestion. Impaction just anterior to the rec- 

 tum will frequently be found as the result of a melanoma 

 involving the rectum or its surroundings. 



Melanosis affecting internal organs, such as the spleen, 

 the liver, or other important organs, the heart at times, 

 is not considered in this chapter because the symptoms 

 produced do not vary from other malignant processes 

 in these parts. The diagnosis is only made on autopsy. 

 The treatment, even were an ante-mortem diagnosis made, 

 would no doubt be futile. 



It is well to bear in mind, however, that obscure abdom- 

 inal and thoracic affections, especially those of a sub-acute 

 or chronic nature, in white or grey horses may be the 

 result of melano-sareoma in the organ suspected. 



