348 BOVINE PATHOLOGY, 



CHAPTER VII.— DISEASES OF THE OEGANS 

 OF SPECIAL SENSE. 



Section 1. — Abnoemalities op the Skin. 



The skin of the ox is remarkable for its thickness, and 

 in some parts it is very loose^ as where it forms the 

 " dewlap/^ In other respects it somewhat closely resembles 

 that of other quadrupeds. Under healthy conditions it is 

 soft, elastic, and pliable, and the coat lies evenly and 

 smoothly. The animal or its fellows apply sharp rasping 

 friction to the surface of the integument by means of the 

 rough tongue with its horny epithelium. Ordinarily the 

 skin is loose and flexible, but when the animal is in a 

 state of ill health it becomes dry, harsh, and tightly 

 bound to the tissues beneath it. This state is known as 

 '' hidebound/* and is not a disease. It is generally accom- 

 panied by a '' staring coat/' due to erection of the hairs 

 in consequence of the minute muscular bundle of each 

 hair-follicle contracting in a spasmodic manner, as a result 

 of perversion of nervous energy. This is one of the general 

 signs of ill health to which we have had occasion fre- 

 quently to allude. It especially accompanies the rigors 

 which are indicative of the invasion of a febrile attack. 

 The disorders of the skin are divisible in the following 

 manner, primarily, into two classes : 



^Inflammatory — Eczema, Psoriasis, Impetigo, Erythema, 



I Ecthyma, Herpes, Urticaria, Pemphigus, Furunculus. 

 Hypertrophic— 'Nadvns, Warts, Elephantiasis (Sclero- 

 NON-PAEASITIC <{ derma), Dermo-pilous cysts. Pityriasis, Keratoid. 



I Atrophic — Alopecia. 

 Functional — Bloody sweat. Emphysema, (Edema, Pru- 

 1^ ritus. 

 p J Animal — Phthiriasis, (Estriasis, Acariasis. 



L Vegetable — Tinea ; var. (1) tonsurans, (2) favosa. 



In examining the list of skin diseases affecting the 



