CHAPTER XX. 



LICE, MANGE, RINGWORM, LUMP-JAW, 

 BLACKLEG, AND TEXAS FEVER' 



Cattle Mange (Texas Itch, Cattle Scab, or Range 

 Itch) is a skin disease affecting cattle only, and is caused 

 by a minute animal parasite Psoroptes communes very 

 closely related to the mite that causes scab in sheep. 

 It is not known that the sheep mite ever infest cattle, 

 nor will the cattle mite injure sheep. The mite is very 

 small, barely visible to the naked eye. It can very read- 

 ily be detected by scraping the surface of the skin with 

 a sharp instrument and allow the substance scraped off 

 to remain five to ten hours in a clean, wide-mouthed bot- 

 tle. White specks will appear on the surface of the 

 glass, which, on examination with a lens, show the de- 

 tails of the parasite. 



Cattle mange appears to be more troublesome dur- 

 ing the late fall and winter than at any other time of 

 the year, and usually disappears in the spring when the 

 cattle are turned out on pasture. Cattle of all ages may 

 become affected, but it seems to be more pronounced 

 in yearlings and bulls; on bulls perhaps, because they 

 come in contact with more animals and are more liable 

 to become infected. 



The first symptoms noticed are intense itching of 

 the skin, usually in the region of the neck and shoulders, 

 and shedding of the hair on the neck and withers. In 

 aggravated cases the irritation may extend all over the 

 body, but the most prominent points where the disease 



'The information here presented on Lice and Mange is taken 

 f rom Bullet in of the Agricultural Experiment Station of Nebraska, 

 vol. XIV., Article IV.; on Ringworm from Report of Bureau of 

 Animal Industry, Diseases of Cattle. 



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