CATTLE LICE AND HOW TO ERADICATE THEM. 7 



brisket, back, inner surface of the thighs, and on the head, around 

 the nose, eyes, and ears. When animals are very lousy the entire 

 surface of the body may become involved. The sucking lice obtain 

 i heir food by puncturing the skin of the host and feeding on the blood 

 and lymph. When feeding they attach themselves to the skin by 

 burying their sucking tubes in the tissues. When not feeding they 

 move about over the hair and skin. 



The biting lice usually are found on the withers and around the 

 root of the tail, but they may occur on any part of the body. They 

 apparently feed on particles of hair, scales, and exudations from the 

 skin. Ordinarily they do not irritate the animals as much as suck- 

 ing lice. When present in large numbers, however, they often form 

 colonies or groups around the base of the tail, over the withers, and 

 on other parts of the animal, and produce lesions resembling those of 

 scab. These lesions vary in size from that of a 25-cent piece to 4 or 

 5 inches in diameter. The skin over these areas appears to be raised 

 and ringworm may be suspected, but when the lesion is" manipulated 

 the scarf skin falls off, exposing the lice grouped on the raw tissues 

 beneath. Under such conditions the irritation is very great and the 

 damage to the animal may be fully equal to that caused by scab. 



When separated from their hosts the biting lice live about 7 days, 

 the sucking lice only about 4 days. Ordinarily eggs are not deposited 

 except on the host, but when the hair to which they are attached is 

 removed and kept under fairly favorable conditions, they may con- 

 tinue to hatch for as long as 20 days. The newly hatched lice live 

 >nly 2 or 3 days unless they find a host. 



The longevity of the lice and the viability of their eggs when sepa- 

 rated from the host have an important bearing on the problem of 

 eradication. The parasites and eggs may become dislodged from 

 the animals, drop in the corrals, stables, and pastures, and tempo- 

 rarily infest the premises. It seems reasonably certain that all lice 

 that remain off the animals, even under the most favorable condi- 

 tions, die within 7 or 8 days, and if the weather is cold and conditions 

 unsuitable they die in less time. The eggs dislodged from the ani- 

 mals, however, may continue to hatch if the weather is mild, and 

 thus be the means of temporarily infesting the premises. 



Before using infested corrals or premises such as stables, sheds, 

 or lots for clean or dipped cattle they should be cleaned and disin- 

 fected as a precaution against reinfection from dislodged lice and 

 egirs. Remove all litter and manure, cleaning down to a smooth 

 surface, then spray all walls, woodwork, and floors with a good dis- 

 infectant. The coal-tar creosote dips, diluted in accordance with 

 instructions on the container, are suitable for this purpose. After 

 dipping or treating animals to free them from lice they should be 



