GENERAL PART OF EXAMINATION. 51 



7. Scales {squamae) are epidermic lamellae which have be- 

 come detached from the skin's surface. 



8. Scabs, or crusts, are dried masses of exudate upon the sur- 

 face of the integument. 



9. Hives (urticaria, nettle rash) are due to swellings of the 

 papillary bodies, producing well-defined evanescent rounded ele- 

 vations, resembling welts raised by a whip. 



I. Non-parasitic Skin Diseases. 



1. Alopecia (baldness) is a loss of hair due to some disturb- 

 ance in the skin's nutrition. It may not be attended by lesion, 



2. Blood sweating (hematidrosis) is the spontaneous appear- 

 ance of blood upon the apparently intact surface of the integument. 

 It is peculiar to Hungarian and Oriental horses. 



3. Prurigo is a papular eruption accompanied by intense itch- 

 ing. Biting and rubbing induce additional lesions. 



4. Summer surfeit {acne simplex) is a nodular eruption occur- 

 ring usually over the neck and shoulders, leading to a loss of hair. 

 [It is seen mostly during the hot months. This condition is often 

 erroneously attributed to some "disorder of the blood." Its chief 

 cause is neglect of proper grooming and care of the skin of horses.] 



5. Fagopyrism is an acute, diffuse, itchy inflammation of the 

 non-pigmented skin of the head, due to grazing on growing buck- 

 wheat in bright sunshine. Brain symptoms sometimes compli- 

 cate the disease. 



6. Eczema. In a general way the term eczema designates an 

 exudative dermatitis. It has much in common with the catarrhs 

 of mucous membranes, and like the latter can pass through the 

 varied stages of erythema with desquamation, papule, vesicle and 

 pustule formation and finally squammae. It is very common in 

 dogs, appearing along the back and tail. 



7. Foot eczema, produced by potato residue, swill and brewer 

 grain feeding, is a vesicular eczema occurring on the hind legs of 

 the ox. The vesicles rupture soon after formation and their con- 

 tents dry to thick yellow scabs. The hair of the affected parts 

 stands erect and part of it falls out. In most instances the eczema 

 reaches no higher up the legs than the hock, but may spread to 

 the body or involve the anterior limbs. 



