Scabies of the Horse. 94]^ 



maintains an inflammatory j^rocess, and in this way indirectly 

 promotes the multiplication of the mites. The disease is com- 

 paratively little infectious, being sometimes confined to one leg 

 for a month without passing on to the extremity of the other 

 side. The prognosis is also rather favorable since the disease 

 attacks large surfaces of skin only in very badly neglected ani- 

 mals, and even then it exerts no injurious effect on the general 

 condition of the animal but quickly disappears with suitable 

 treatment. 



Diag-nosis. Although one can recognize mange Avith abso- 

 lute certainty only by microscopic examination and this exam- 

 ination seems very necessary in order to distinguish sarcoptic 

 from^ dermatocoptic scab, yet the clinical signs furnish 

 sufficient points in most cases. Eczematous inflammation to- 

 gether with the characteristic itching always point to scab; 

 severe changes in the skin, and even more a considerable ex- 

 tension of the inflammation which is not sharply circumscribed, 

 as well as marked thickening of the skin will be noticed rather 

 in sarcoptic scab than in that occasioned by the dermatocoptes 

 mites ; besides sarcoptic scab is of a very much more obstinate 

 character. In cases that are not neglected, it is generally pos- 

 sible to differentiate the two forms of scab by the localization 

 of the skin changes. 



True eczema generally develops at once on a large surface 

 of the skin, the stages of nodules, vesicles and moisture are 

 more pronounced and the itching is only moderate, nor is it in- 

 creased to any considerable degree by warmth. Pemphigus is 

 also accompanied by extremely severe itching, but the copious 

 serous exudation and the large vesicles are characteristic of 

 this disease. Other animal parasites such as ticks, lice, and 

 exceptionally the dermanyssus avium sometimes cause intense 

 itching and later on severe eczema, yet their presence may al- 

 ways be determined by a close inspection of the hair ; one should 

 always bear in mind the skin disease caused by the dermanyssus 

 avium if coops are found in a horse stable. Dermatophagic 

 scab might be confounded with eczema of the fetlock joint. In 

 this, however, there is no severe itching, and besides the para- 

 sites are very easily identified in foot scab. 



Treatment and Prophylaxis. The treatment differs in part 

 according to the kind of mites present and also according to 

 the extension and severity of the disease. The sarcoptic mites 

 are much harder to destroy than the two other kinds of mites 

 which live superficially on the skin and in and under the en- 

 crustations; on this account energetic remedies are generally 

 employed against the sarcoptic mites, and these are applied 

 repeatedly and left for a long time in contact with the skin. On 

 the other hand, the treatment of a very extensive case re- 

 quires great care and perseverance because the skin changes 



