Diseases of the Skin. 245 



The principles of Treatment laid down for sarcoptic 

 mange must be rigidly adopted in this disease. Frequent 

 and thorough dressing must be persisted in, especial at- 

 tention being directed to removal of the crusts in order 

 that the dressings may reach the parasites within the hair 

 follicles. Suitable formulae will be found in Chapter VIII. 

 under the head of Parasiticides. As in sarcoptic mange 

 the removal of hair by close clipping, or even shaving, 

 must be carried out efficiently and without hesitation 

 when desirable. The advice concerning removal of the 

 crusts given under sarcoptic mange is especially needed, 

 frequent baths and subsequent dressings, probably con- 

 tinued for months, being needed before any improvement 

 is evident. As v/e have already remarked, the parasites, 

 by reason of their location, are extremely difficult to attack, 

 and even, if we are successful, yet another problem awaits 

 us, viz., the ova, which may be hiding away on such parts 

 as have been restored by destruction of the parents. Care 

 must be exercised also with regard to lodging and beds. 

 Kennels require cleansing, and nothing answers so effec- 

 tually as strong and boiling-hot solutions of caustic potash 

 or soda, which should be used liberally by means of a 

 large painter's brush. The best bed is pine shavings, 

 frequently renewed; when they are not accessible, clean 

 hay or straw may be used, which should be regularly 

 dressed with water containing one-twentieth part of crude 

 " Sanita?,"and allowed to dry before being put into use. 

 Beds of whatever kind, having served their purpose, should 

 be summarily burned. 



The Harvest Bug, or Leptus autumnalis, the larval 

 hexapod of the Tetranychus autumnalis^ proves a trouble- 

 some parasite to the human subject, giving rise to 

 painful boils. It also attacks animals, especially dogs, 

 during the hot months of July and August, afterwards 

 passing through other developmental changes, and is lost 

 sight of. When it reaches the skin it may be detected 

 by its bright red colour, and if not speedily removed it 

 shortly burrows in the skin, giving rise to irritation. 

 When the parts are rubbed the parasite ejects an acrid 

 secretion, which, with the burrowing operations, produces 



