The Head and Neck 65 



from two to six weeks, but as the trouble is prone to recur the ears 

 should subsequently be periodically examined. 



In the parasitic form, parasiticides are, of course, indicated. 



To ensure local applications reaching all parts of the canal the 

 base of the ear must be manipulated between the thumb and finger. 



If the shaking of the fliaps is violent enough to threaten the 

 production of hematoma or ulceration of their borders the protective 

 ear-cap may be employed. 



SINUS. 



A very rare form of sinus which is caused by the presence of a 

 dermoid dentigerous cyst in the temporal region may have its orifice 

 of discharge within the auditory canal (See The Teeth). Suppura- 

 ting lymphatic glands will also sometimes break through and dis- 

 charge into the auditory canal, thereby simulating otorrhea. 



NEOPLASMS. 



Two forms of neoplasms are commonly met with in the ear. 

 They are both innocent. They occur as papillomata which develop 

 in the vestibule of the outer ear, and as contusion or extravasa- 

 tion cysts (hematomata) which form beneath the integument of the 

 concha. Sebaceous adenomata have also been observed. 



Papillomata. These tumors occur as single or multiple, flat, 

 coin-shaped or cauliflower-like excrescences. When numerous they 

 may extend well within the vestibule and block the canal. From 

 their surface they usually discharge a fetid, greasy matter. They 

 occur as the result of chronic otitis. 



Symptoms and Diagnosis. The symptoms are identical with 

 those of chronic otorrhea, and the presence of the growths is as- 

 certained only by close inspection of the auditory canal. The animal 

 is often deaf. 



Treatment. By far the most effective method of treating this 

 disease is complete destruction of the tumor with the thermo-cautery. 

 Ablation by snipping at the base of the growth with curved scissors, 

 as advocated by some authors, I cannot recommend, as it is uncer- 

 tain in result and is usually followed by recurrence of the trouble. 

 Cauterization is effected with the animal in the lateral position under 

 complete anesthesia. The burning process must be thorough. The 



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