618 DISEASES OF SWINE 



of wallow-holes or in the soil of low-lying pastures. Chronic irri- 

 tation of the skin by hce and other parasites may result in the 

 development of an eczema. During hot weather the skin may 

 become irritated from the effects of the rays of the sun. This 

 is particularly likely to occur in white hogs and in hogs that 

 have a Ught coat of hair. The charcoal that remains after 

 burning a pile of corn-cobs is quite irritating, and if animals are 

 allowed to wallow in the pools of water that form in these ash- 

 piles after a rain severe eczema and even sloughing of the skin 

 may follow. 



Eczema is a disease that is especially likely to occur in weak, 

 debilitated animals that are run down as the result of some other 

 disease, such as rheumatism, rickets, chronic hog-cholera, or 

 chronic indigestion. 



Symptoms. — This disease makes its appearance in the form of 

 an eruption of the skin, appearing especially on the inner surface 

 of the thighs, sides of the chest, along the belly, and on the inner 

 side of the forelegs. Occasionally it may appear also on the eye- 

 lids, muzzle, and other parts of the body. In pigs suffering with 

 scours an eczema often appears on the hind parts where they are 

 soiled with the irritating discharges from the bowel. 



Eczema is especially noticeable in white hogs, owing to the color 

 of the skin and the ease with which eruptions may be noted on it. 

 The affected parts are red in color, swollen, inflamed, and quite hot 

 and painful. Intense itching and burning is an especial feature of 

 eczema, and the animal will rub or bite at the affected parts al- 

 most continuously. The lesions at first consist simply of reddened 

 elevations on the skin, but a little later these are covered with small 

 blisters, filled with a clear, sticky, honey-like fluid. This soon 

 becomes converted into pus, and then the blisters break and crusts 

 are formed. These crusts, by admixture with dirt, have a black, 

 greasy appearance. 



As a result of the irritation the animal is restless, appetite is 

 irregular, and the hog takes on an unthrifty appearance. In run- 

 down pigs the disease may prove very severe and the animals die 

 of exhaustion. When the disease has lasted for several weeks or 

 months large sores develop on the affected parts and the skin be- 

 comes thickened and cracked. Where the disease is allowed to 



