DISEASES OF THE SKIN.— EXTERNAL PARASITES. 203 



and usually of considerable extent. The vesicles are so 

 closely aggregated in some situations, as to give rise to one 

 continuous vesicle of great breadth. These larger vesicles, 

 when laid open, appear to be cellular in their structure ; the 

 cellular disposition obviously depending on the juxtaposition 

 of the numerous small vesicles of which they are composed. 

 The vesicles of eczema terminate by absorption of the fluid 

 which they contain, or by rupture and moist excoriations suc- 

 ceeded by thin crusts, and by furfuraceous desquamation. 

 The eruption is generally successive, and ■ variable in dura- 

 tion ; it sometimes extends to the mucous membrane, and is 

 often developed on the scalp and hair-bearing parts of the 

 body.* 



All dogs are liable to become eczematous, and those used 

 for sporting purposes more particularly so. One attack pre- 

 disposes the animal to another, and the latter frequently es- 

 tablishes chronic eczema. 



Causes. — Insufficient exercise and injudicious feeding are 

 the two chief causes of eczema in dogs. A too stimulating 

 diet, an excessive supply of animal food, a denial of the ex- 

 ercise necessary in such cases to balance the effect of these 

 measures, result in an over-charged and over-heated system, 

 and nature, to avoid worse consequences, endeavors to get 

 rid of this pressure by means of serous outpouring or exuda- 

 tion. 



Treatment. — Saline aperients are in the first instance ad- 

 visable ; when the irritation is extreme and considerable con- 

 stitutional disturbance is manifested, a grain each of opium 

 and calomel may be administered with benefit. 



With regard to local applications, the skin should never 

 be washed or rubbed, in the dressing with agents, more than 

 is absolutely necessary. The benzoated oxide of zinc oint- 

 ment, smeared over once or twice a day is a very effectual 

 remedy. Another exceedingly useful one is : 



* Wilson's " Diseases of the Skin," p. 164. 



