338 DISEASES OF CATTLE. 



evidence of contagion. The acari can be detected upon the hair and 

 surface of the epidermis by the aid of an ordinary magnifying glass, or 

 they may be' seen with the naked eye as minute white points moving 

 about Avhen the infested animal stands in the full glare of the sun on a 

 warm day. 



Ghorioptes symbiotes var. bovis (Syinbiotes bovis). This variety of 

 the acari rarely affect cattle. They generally live at the base of the 

 tail; through neglect they may extend along the back or down upon 

 the thighs. This type of mange is not nearly so contagious as the 

 former variety, though in all other respects it produces similar effects. 

 This variety is best seen by picking off a scab and laying it on a piece 

 of white paper, which is then placed in the sun. The next day the 

 parasites may be found in clusters. 



Treatment. It is of the utmost importance to cleanse the skin, 

 removing crusts, etc., before the parasites can be effectually eradicated. 

 For this purpose use soft soap and warm water, and give the animal a 

 thorough scrubbing, especially in regions where the skin has been 

 rubbed. If the crusts are not all removed by the first washing, apply 

 sweet oil to soften them. They may then be washed off the following 

 day. To kill the mites apply thoroughly, with a brush, the following 

 mixture: Creolin, 1 ounce; oil of tar, 1 ounce; soft soap, pint; sulphur, 

 pound; alcohol,! pint. Wash it off in two days with soap and water. 

 Three or four days later a second application should be made to destroy 

 all remaining acari. It is essential that the stable or stalls where 

 affected cattle have been should be cleansed and whitewashed, or satu- 

 rated with sulphuric acid 1 pint to 3 gallons of water. 



PHTHIEIASIS LOUSINESS. 



The lice of cattle are of two kinds, the suctorial lice, belonging to 

 the family Pediculidra of the order Hemiptera (sub-order Parasita), 

 which are found only upon mammals. The other variety biting lice 

 belong to the family Philopteridre of the order Pseudoneuroptera (sub- 

 order Mallophaga), which attack mammals and fowls. Those belong- 

 ing to the first variety are the short-nosed ox-louse Hcematopinus 

 eurysternus and the long-nosed ox-louse Hccmatopinus vituli (Syn. H. 

 tennirostris). The short-nosed ox-louse is the larger and the harder 

 to exterminate. It infests almost exclusively the neck and shoulders, 

 and those parts are frequently worn bare by the animal in its efforts 

 to rid itself of these tormentors. The full-grown females of the short- 

 nosed ox-louse are from one-eighth to one-fifth of an inch long, and fully 

 half that in width, while the males are slightly smaller. The males 

 have a broad, black stripe running forward from the end of the body 

 to near the middle of the abdomen ; the females have no indication 

 of this stripe. The true pumping organ, as in all the Pedieulidse, con- 

 sists of a slender piercing tube which may be greatly extended in order 

 to reach the blood of the infested animal. 



