ELEVENTH ANNUAL YEAR BOOK— PART X 541 



Transmission of scabies is generally by immediate contact; con- 

 tagion will especially take place, easily, when shorn mangy sheep 

 are introduced into a healthy flock, especially in hot sheep-folds 

 where the animals are crowded together, and during winter when 

 the wool is long. 



The symptoms are first manifest upon the croup, base of the tail, 

 back, sides, neck and shoulders. The eruptions commence with 

 small spots, which may be isolated or in groups, according to the 

 extent of the infection. By spreading the wool apart we observe 

 flattened pimples the size of a millet seed, of a pale yellow or red- 

 dish coloi- produced by the bites of the mite. These spots become 

 enlarged and confluent, which dry up, forming large scabs, and 

 an abundant epidermic desquamation is produced, which forms 

 thick crusts by becominug mixed with sebaceous matter and the 

 contents of the pustules. 



These scabs are often hard and of yellowish-brown color, under 

 which the parasites hide and lay their eggs. 



The wool becomes loosened and flaky tufts appear upon the sur- 

 face and fall out, the wool loses its luster, the affected sheep rub 

 themselves against convenient objects; also bite and tear out the 

 wool about the affected parts. When the disease becomes general- 

 ized the affected animals become emaciated, weak and die. 



Sheep scab is one of the most annoying and destructive diseases 

 from a pecuniary standpoint, being destructive to fleece and ani- 

 mal, if not promptly and vigorously treated. 



Scabies became so prevalent throughout the country, and espe- 

 cially upon the western ranges, that federal and state co-operation, 

 along vigorous lines became necessary, and the present outlook in- 

 dicates that complete success in eradicating this disease will soon 

 be a fact. 



Iowa law regarding diseased sheep will be found in Title XII, 

 Chapter 3, of the Code, copy attached to this report. 



During the past several years outbreaks of scab in sheep have 

 been investigated in many localities in northwest Iowa. Through 

 the co-operation of the Bureau of Animal Industry with our State 

 Veterinary Department, these infections have been stamped out 

 by proper dipping and hygienic measures. 



The treatment of scab consists in using some external applica- 

 tion, which by contact will destroy the parasite and eggs, and this 

 can be effectually done only by repeated dipping. 



