Symptoms. 849 



layer is markedly so, the sweat and fat glands l)ecome atrophic, 

 and the skin, which has in the meantime become rough, is only 

 capable of incomplete improvement (E. chronicum). 



Symptoms. The changes sketched above run their course 

 on the skin, and may, therefore, easily be watched on the living- 

 animal. In contrast to other skin diseases, one notices many 

 variations in the morbid changes in their development, and es- 

 pecially a rapid development of papules and vesicles, as well as 

 moist spots only covered by the deepest layer of cells, and 

 formed by the papillae, which come plainly into view after the 

 crusts are removed. The recognition of the disease is also 

 made easy by the fact that in some cases the different stages of 

 development of the changes may be seen at the same time on 

 the affected animals, and in this way the progress of develop- 

 ment may be established by comparison, even without any 

 history. On the other hand the little pathological forma- 

 tions easily escape because of the hair coat, and moreover severe 

 inflammatory processes are caused by scratching, gnawing and 

 rubbing, which are associated with hemorrhage and suppura- 

 tion and affect not only the skin but also the subcutaneous con- 

 nective tissue. This fact interferes with the clearness of the 

 clinical picture. 



Itching always accompanies this skin disease, and is the re- 

 sult of irritation of the nerve endings situated in the papillae, 

 wdiich are subject to serous and cellular infiltration. It is es- 

 pecially intense in the acute cases as well as in extensive inflam- 

 mation; it disturbs the animal considerably and is not depend- 

 ent on the external temperature or on the time of day. 



In acute cases fever sometimes arises, and a feverish 

 exacerbation coincides with a fresh appearance of vesicles. 



The great restlessness caused by the itching, the fever, as 

 well as the long continued loss of albumin from the moist sur- 

 faces, considerably affect the condition of the animal in chronic 

 cases, and in consequence this skin affection, which is benign 

 of itself, may lead to considerable emaciation and even to com- 

 plete exhaustion. 



In the various species of animals the clinical picture of 

 eczema is essentially the same, but in particular points devia- 

 tions may be noticed which are important, both as regards the 

 course and diagnosis of the affection, and which on this account 

 will be mentioned separately, together with some etiological 

 considerations. 



(a) Eczema of the Horse. 



In horses eczema chronicum (chronic squamous eczema, 

 Kleien und Schuppenflechte, Hungerraude [German] ; eczema 

 sec [French]) occurs particularly from insufficient nourish- 

 ment and faulty skin hygiene, and develops in tender skinned. 



