It is much more difficult to do this with the sarcoptic form than 

 with the other two, owing to the burrowing habits of its parasites, 

 and the fact that it is only about half their length a.nd breadth. 

 In order to find the insect, scrape the surface of the affected skin 

 with a knife, through the scarf-skin until blood is drawn, and gently 

 heat the crusts thus collected until dry before a fire or in the sun. 

 Examine a small amount of this dust on a glass plate by direct 

 light by means of a microscope magnifying 40 or 50 diameters. 

 Warmed by sunlight, the insects can then be seen moving about. 

 To examine them more carefully, remove specimens from the dust 

 by the point of a needle, put them on a drop of glycerine on 

 another glass, place a cover glass over them, and put them under 

 a microscope magnifying from 150 to 500 diameters. Or place 

 the warmed crusts on black paper and examine them with a 

 strong magnifying glass, which will be sufficient to show any 

 psoroptes or symbiotes that may be present. Or soak the crusts 

 for a couple of hours in a ten per cent, solution of caustic potash, 

 which by its power of dissolving albumin will free the insects from 

 the dibris with which they are surrounded, and then put the now 

 colourless crusts under a cover glass. 



Sarcoptic mange may be mistaken for that due to poultrjt mites ; 

 and vice versa. 



TREATMENT OF THE VARIOUS KINDS OF PARASITIC 

 MANGE. — ^Here, the first object is destruction of the parasite. 

 In using applications for that purpose, guard against irritating 

 the skin too much; producing symptoms of poisoning by absorp- 

 tion; and injuriously interfering with the function of the skin, 

 which might be done by covering too large a surface with oily or 

 fatty matters. Treatment of an invasion of sarcoptes should 

 extend over the whole surface of the body, on account of the 

 roving habits of these insects ; but not more than half of the body 

 should be dressed at one time. Unless the coat is short, in all 

 cases clip the horse (generally, for the sarcoptes; locally, for the 

 other two). In psoroptic mange, in order to disfigure the animal 

 as little as possible, clip the hair of the affected parts of the 

 mane only in the furrows of the wrinkled skin; and make 

 transverse openings (partings) through the hairs of the tail to 

 facilitate cleaning and dressing. If this clipping cannot be done 

 on some unfrequented spot, so that the insects may not have the 

 chance of making a fresh invasion, the removed hairs should be 

 collected together and burnt. The- parasites should next be 

 exposed as much as possible to the action of the agent intended 

 for their destruction, by washing the parts thoroughly, by rubbing 

 soft, soap into them. Then scrub the surface with a brush and 



