44 CLINICAL DIAGNOSTICS. 



In the fall the long, soft winter coat appears ; this is shed the 

 following spring. [Animals kept blanketed in warm stables 

 retain a short hair coat throughout the winter.] Good care 

 and proper food hasten the shedding of the hair, contrary con- 

 ditions tend to postpone it. When the winter coat is retained 

 during the summer months, it indicates usually chronic disease 

 of nutrition. 



W'hen horses which have been poorly kept pass into good 

 hands and receive nourishing food and good attention, an 

 unusually early shedding of the winter coat follows. 



Alopecia. A loss of hair over the whole or a large 

 part of the body (alopecia) sometimes quickly follows the re- 

 covery of an animal from a severe infectious disease (con- 

 tagious pleuropneumonia of the horse). A gradual loss of 

 coat accompanies chronic, cachectic diseases in sheep and 

 dogs. In chronic diseases affecting nutrition the hairs be- 

 come loose, and may be easily removed by pulling or rubbing. 

 Horses clipped late in the season (November, December) grow 

 short winter coats ; when these are shed the following spring, 

 the skin is left partially denuded of hair, giving the animal 

 a half-naked appearance. 



Where the hairs fall out in patches, and lesions are found 

 in the skin, a disease of the integument is present. 



II. Sweat secretion. The skin is kept continually 

 moist by the secretions of the sweat glands. In healthy ani- 

 mals at rest the supply of secretion is just sufficient to keep 

 pace with the loss by evaporation, so that the skin does not 

 feel wet but soft and pliable. The skin's moisture is increased 

 by exercise, high atmospheric temperatures and nervous ex- 

 citement. Sweating does not become visible in swine, sheep, 

 dogs, and cats. 



In disease a more or less profuse outbreak of 

 sweat {hyperidrosis) appears : — 



1. When an animal is much weakened from acute or 

 chronic disease. 



