DiseasBi of the Ear. 195 



POLYPUS. 



The formation of polypus on the lining membrane of the 

 external meatus is not uncommon in the dog. The tumour 

 usually assumes one of two forms : the soft and vascular 

 situated in the anterior half of the meatus, or the full and 

 fleshy (sometimes fibro-cartilaginous), in the lower half of 

 the meatus. 



Causes. — Protracted irritation or chronic inflammation 

 of the lining membrane of the meatus, or of that covering 

 the tympanum. 



These tumours, when small and quiescent, are not at- 

 tended with any great inconvenience ; but when they 

 become irritable, and the animal, in his attempts to rid 

 himself of the offending body, increases the irritability, 

 they rapidly increase in size, and give rise to deafness, 

 pain, giddiness, and other untoward results. 



Symptoms. — In describing the symptoms of this a.ffec- 

 tion, I cannot do better than follow the example of other 

 authors, in transcribing a portion of Dr. Mercer's paper in 

 the " Veterinarian" for 1834, on this subject : 



" Polypi produced from the tissues of the meatus maybe 

 divided into two kinds : 



" First, the soft vascular and bleeding polypus, usually 

 produced from the fibro-cartilaginous structure of the 

 outerhalf of the tube ; and, secondly, the hard and cartila- 

 ginous polypus or excrescence produced from the lining 

 membrane of its inner half. 



" As to the first of these forms of polypi, the haematoid, 

 that arise from the external soft structure of the tube, they 

 may be situated in any part of its. parietes, but most com- 

 monly at its superior and posterior surface. In form they 

 are generally pedunculated ; their surface is rough, 

 irregular, and glistening, in consequence of being covered 

 with a thin layer, of mucus, which is often tinged with 

 blood, especially when any degree of violence has been 

 0—2 



