DISEASES OP THE SKIN. 



327 



indolent sores or fissures, the white precipitate ointment, nitrate of 

 mercury ointment, or blue ointment, mixed with equal parts of cos- 

 moline or fresh lard, may be applied every second day, taking care to 

 protect the parts so anointed that the animal can not lick it off. 



In some cases the use of the following mixture will do well : Oil of 

 tar one-half ounce, glycerin 1 ounce, alcohol 1 pint. Rub this in 

 after cleansing the parts with warm water and soap. The internal 

 administration of arsenic often yields excellent results in chronic 

 eczema. Take 1 dram of arsenic, 1 dram of carbonate of potash, 1 

 pint of boiling water, and give 1 ounce of this twice a day in water, 

 after feeding. An alkali internally may be of service. As such, one 

 may give 2 ounces of bicarbonate of soda twice daily. Sublimed sul- 

 phur may also be tried in ounce doses twice daily. 



PUSTULES (IMPETIGO). 



Impetigo is an inflammatory disease of the skin, characterized by 

 the formation of distinct pustules, about the size of a pea or a bean, 

 unattended by itching. The pustules develop from the papular layer 

 of the skin, and contain a yellowish white pus. After reaching 

 maturity they remain stationary for a few days, then they disappear 

 by absorption and dry up into crusts. Later the crusts drop off, leav- 

 ing upon the skin a red spot which soon disappears. Occasionally the 

 crusts remain firmly adherent for a long time, or they may be raised 

 and loosened by the formation of matter underneath. The dry crusts 

 usually have a brown or black appearance. 



Causes. — Impetigo affects" sucking calves, in which the disease 

 appears upon the lips, nostrils, and face. It is attributed to some 

 irritant substance contained in the mother's milk. Impetigo is also 

 witnessed among grazing animals, regardless of age, and it especially 

 attacks animals with white hair and skin. The mouth, face, and 

 limbs become covered with pustules,, which may rupture in a few 

 hours, followed by rapid and successive incrustations; the scabs fre- 

 quently coalesce, covering a large surface; pus may form under them, 

 and the whole thickness of the skin become involved in the morbid 

 process. This form of the disease is attributed to the local irritant 

 properties of plants growing in the pasture, such as St. John's 

 wort (Hypericum perforatum), smartweed (Polygonum hydropiper), 

 vetches, honeydew, etc. Buckwheat, at the time the seeds become 

 ripe, is said to have caused it, also bedding with biickwheat straw. 



Treatment. — Sucking calves should be removed from the mother, 

 and the latter should have a purgative to divert the poisonous sub- 

 stance secreted with the milk. When the more formidable disease 

 among grazing cattle appears, the pasturage should be changed, and 

 the affected parts of the animal thoroughly anointed once a day with 

 sweet oil, containing 2 drams of carbolic acid to the pint. This should 

 be continued until the crusts soften and begin to drop off, then the 



