10 



important to refer to this form of mange parasite and occupy space 

 in this bulletin except by a reference to the serious disease which is 

 produced by this variety of mite through certain characteristics nat- 

 ural to it. We find Sarcoptic mange in the following domesticated 

 animals: Horse, sheep, goat, dog, cat, and pig. 



This variety dig galleries under the outer layer of the skin and live 

 on the cells of the middle layer of the skin. They multiply in these 

 galleries and occasion a very intense inflammation of the skin. Because 

 of the depth to which the Sarcoptes burrow Sarcoptic mange is exceed- 

 ingly hard to eradicate. It would, therefore, seem fortunate that this 

 form of the disease is not common to cattle. It is rebellious to all medi- 

 cation, and very frequently recurrences of the disease are seen after 

 treatment which has been prolonged for months. 



TRANSMISSIBILITY OF MANGE. 



Concerning the transmissibility of the different manges to animals 

 and man, we find that all Sarcoptes may live for a considerable period 

 upon man's skin, but the common mange mites, the first variety 

 described, and the tail-mange mites, the second variety described, die 

 very rapidly and occasion but slight irritations. The horse may con- 

 tract Sarcoptic mange of the sheep, pig, dog, and cat. The ox takes 

 the Sarcoptes of the horse, sheep, goat, and cat. The sheep contracts- 

 Sarcoptic mange of the goat. The dog takes the Sarcoptes of man, pig, 

 cat, sheep, and goat. The pig contracts Sarcoptic mange of the goat. 

 From this it will be se*en that Sarcoptic mange, unlike the common and 

 tail manges, is transmissible from one species of animal to another. 



Mange is never developed except by contagion. The period of 

 incubation that is, the interval that elapses between the moment when 

 the mites are deposited upon the surface of the body and the appear- 

 ance of the disease on the skin varies according to the number of 

 mites transmitted. When in small numbers, the first manifestations 

 of mange are sometimes seen as late as four to six weeks, while at 

 other times the disease may be clearly apparent at the end of 15 days. 

 Contamination takes place either by direct contact that is, imme- 

 diate, as on pasture, at the stable, etc. or by intermediary agents. 



DISINFECTION. 



What has already been said with regard to the contagious character 

 of scabies in cattle of the number of scab mites which may be found 

 in a small quantity of the debris of the skin and their ability to live 

 and remain active for a considerable length of time under unfavorable 

 conditions will indicate the importance of the thorough disinfection of 

 corrals, sheds, or other buildings in which affected cattle may have been 

 kept. It is therefore necessary, in order to attain success in the treat- 



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