ANIMAL PARASITES OF CATTLE. 517 



CRUDE-PETROLEUM DIPS. 



Crude-petroleum dips, which are vahiable for the treatment of 

 sarcoptic mange, are not often used for the treatment of psoroptic 

 mange or of chorioptic mange, oily dips being liable to injure animals, 

 especially if they are moved rapidly soon after treatment, if they are 

 exposed to bright sunshine, or if they become chilled. Besides 

 unprocessed crude petroleum, processed petroleum from which the 

 gasoline and other light hydrocarbons have been removed may be 

 utilized in the treatment of cattle for mange, particularly sarcoptic 

 mange. There are a number of proprietary brands of crude-petro- 

 leum dips on the market, consisting of processed ci-ude petroleum 

 with other substances added, mainly lighter oils to give the dip a 

 suitable consistency. In dipping cattle in crude-petroleum dips fill 

 the vat with water to within 1 foot or 18 inches of the dip line and 

 then add the oil until the surface is flush with the dip line. The oil 

 floats on the water, and as the animals pass through the vat their 

 bodies become coated with oil. 



CHORIOPTIC MANGE. 



Chorioptic mange, due to a species of mite difi^erent from that caus- 

 ing common cattle mange, is confined almost entirely to the region at 

 the root of the tail and if not treated may persist for years. The 

 treatment is the same as for psoroptic mange. 



SARCOPTIC MANGE. 



Sarcoptic mange, frequently called "bam itch," is caused by a 

 mite very similar to that which causes itch in human beings. It 

 commonly affects the head and neck, but may also occur on various 

 other parts of the body. Bulls are particularly liable to be affected 

 with this form of mange. Cattle may become infected not only from 

 other cattle, but also from horses, goats, dogs, sheep, and hogs. As 

 a rule sarcoptic mange in any species of animal, if acquired from an 

 animal of another species, is likely to run a short course and tend 

 toward a spontaneous recovery. 



The treatment likely to be most efficacious is that of dipping in a 

 crude-petroleum dip, one treatment as a rule being sufficient. If 

 lime-sulphur dip is used, four or five successive treatments, or even 

 more, at weekly intervals, may be necessary before a cure is effected. 



DEMODECTIC MANGE. 



Demodectic mange, which is caused by a small parasite that lives 

 in the hair follicles, causing pustules, especially on the neck and 

 shoulders, occurs occasionally among cattle in this country and is of 

 importance on account of the injury to the hide. When tanned, 



