ECZEMA. 389 



namely, excessively high temperature, but not high enough to 

 produce vesicles. 



Eczema appears more frequently in summer than in winter, and 

 we have a great deal more difficulty in healing it during the sum- 

 mer weather. We also have a number of eczematous formations 

 for which we can find no cause. In such cases the disease has 

 been ascribed to acids in the blood or diseases of the nervous 

 apparatus, and also to vegetable parasites. 



Clinical Symptoms and Course. Eczema may appear in 

 any breed of dogs, and in any region of the body without regard 

 to age, sex, etc., but, as a rule, it affects old, well-fed dogs, such 

 as terriers. Great Danes, and setters. It is usually seen on certain 

 regions of the body (back, head, neck, and external surface of the 

 extremities). 



There are three general forms of eczema without taking into 

 consideration the changes which may be produced by irritation, 

 scratching, or rubbing. 



The first type is restricted to small, irregularly circumscribed 

 regions, but has a tendency to extend to the neighboring tissues. 

 The eruption begins as eczema papulosum with close nodules. It 

 is rapidly altered into the vesicular layer by change of the nodule, 

 and finally we see the appearance of the median stage. This has 

 a more or less extended surface without skin or hair, and shows 

 a bright red, serous, sero-fibrinous, or purulent exudate, very 

 painful to the touch, and having a great tendency to extend 

 to the adjacent tissues. The stage of crustion follows very 

 slowly. 



The second type shows from the beginning an inclination to 

 extend. In the early stages we see it as eczema erythematosum 

 with formation of scattered papules. These are scratched open 

 on account of the great itching they cause, or they become altered 

 into pustules. Later we see the appearance of small scabs under 

 which regeneration of the epidermis occurs. In the other regions 

 desquamation of the epidermis follows. 



The great tendency to scratching in dogs, notwithstanding the 

 very slight alterations of the cutaneous tissue, may lead to what is 

 classified under another form of skin affection called " prurigo." 

 We must admit, however, with Friedberger and Frohner, that 

 true prurigo does not exist in the dog, and that all the cases 



