DISEASES OF THE EAR, 



Serous Cyst. 

 {Othematoma; Hanatonia.) 



By this term we mean a blood or lymphatic excretion lying between 

 the skin and cartilage of the ear, and forming a tumor in the external 

 or internal part of the lobe. It generally occurs on the inside of the lobe. 

 In rare cases it has been found in the external side, and in still rarer cases 

 both inside and outside. This swelling is fluctuating, and when the skin 

 of the animal is white it may have a bluish coloration. 



Etiology. — This condition is probably due to some irritation or 

 traumatic cause; for instance, by striking the ear against the collar or muz- 

 zle, pulling the ear, concussions, and injuries through biting; or from con- 

 stant shaking the ear due to the continuous itching and irritation of disease 

 of the middle ear and from irritation of parasites, or ulceration of the edges 

 of the lobes. It is alwaj-^s seen in the lobe of the ear; it is general in dogs 

 with long ears. If the sac is not emptied by surgical means, the secretion 

 remains fluid and to a certain extent is reabsorbed, but rarely is the 

 secretion entirely reabsorbed and it may leave quite a thickening and 

 even malformation of the external ear, and when the sac is emptied by 

 surgical means after the collection has been there some time we find that 

 there is very little serous fluid left, but organized masses of filiform 

 neoformations. In some cases when the fluid suppurates it may perfor- 

 ate the skin externally. This, however, is very rare, being generally 

 associated with some later traumatisms. 



Clinical Symptoms and Prognosis. — The swelling, as a rule, is on the 

 internal part of the ear. This enlargement varies in size from a pigeon 

 to a chicken egg, spherical or oval in shape. The lobe, which generally 

 hangs downward, is pushed upward in a peculiar manner (Fig. 151). 

 The swelling is hard, and in white animals it has a blue color. It is very 

 sensitive to pressure and shows a distinct fluctuation. The animal 

 carries its head in an oblique manner, the affected ear being held down- 

 ward, and when the collection is of some size the ear stands out from the 

 head, and the fact that it gives the dog more or less pain is indicated by 

 the careful way that the animal shakes its head or scratches its ear. 



The prognosis is favorable provided proper treatment (incision, etc.) 

 is applied, although it may take some time before they are entirely cured. 

 Compression of the ear by means of bandages has been found to induce 

 the course of healing very materially. 



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