GENERAL PART OF EXAMINATION. 49 



bles, may be at the bottom of emphysema of the integument. 

 Sometimes after rumenotomy or trocaring, gas passes 

 from the paunch through the muscular wound into the sub- 

 cutaneous tissue. The skin wound having shifted position, 

 the escape of the gas to the surface is prevented, hence it 

 collects in the loose connective tissue along the back. 



-j IV. Color of the skin. The hair and pigment prevent us 

 from seeing that color of the skin which is caused by the blood and 

 other physiological fluids flowing through it. With the exception of 

 the horse, nearly all white-coated animals have non-pigmented skins : 

 [Horses having white or grey hair coats show pigmented skins, the 

 white-born (albino) horses forming an exception. The parts of the 

 skin which show white markings (legs, forehead) are as a rule not 

 colored.] 



Chronic discharges from natural openings (the eye, nose, vulva) 

 cause a loss of pigment from the portions of the skin over which 

 they flow. 



An injection (reddening) of the skin is only of 

 diagnostic importance when not produced by local diseases of 

 the integument. A diffuse reddening of the skin, namely of 

 the abdomen, neck and between the thighs, is seen in swine 

 erysipelas (Rothlanf). Red spots, often angular in shape, 

 accompanied by swelling of the skin, appearing usually over 

 the neck and along the back, are seen in urticaria and in mild 

 cases of erysipelas in swine. 



The skin becomes bluish red (cyanotic) when the 

 blood is heavily charged with carbonic acid gas. It is seen 

 in diseases causing swelling of the glottis, heart diseases, con- 

 gestion and edema of the lungs, and in overdriven sheep or 

 swine during hot weather. 



A sharply defined, highly red or dark red discoloration of 

 the ears appears in chronic swine erysipelas (Rothlauf) and iii 

 peracute hog cholera. In the latter the temperature may b,- 

 ■normal or subnormal. 



Yellow (icteric) discoloration and paleness of the 

 skin will be considered under "Examination of the Conjunc- 

 tiva." See page 59.) 



