Sarcoptijormes 365 



It spreads rapidly. Hirst 1922 lists the symptoms as follows: "There 

 are reddish spots rather like flea bites, and the scratching of the ani- 

 mal causes reddish places and papules to appear. The infected part 

 often becomes dry and covered with yellowish crusts. The hair falls 

 out and the skin becomes thickened, wrinkled and creased. Pruritus is 

 intense. The presence of the parasite is the chief distinctive feature." 

 Human beings may become infected with the dog Sarcoptes. The mite 

 is apparently cosmopolitan. Sarcoptic mange of pigs, caused by S. 

 scabiei var. sids, is common in the United States as well as in other 

 countries. The general symptoms are as in the scabies of the dog. This 

 species can also be transferred to man. Sarcoptes scabiei var. ovis 

 Megnin is parasitic on sheep, where it is to be found around the head 

 although in more serious cases the limbs and rarely the body become 

 affected. It is not to be found on the wooly parts of the body. This 

 mite can be transmitted to goats. Sarcoptes scabiei var. caprae FUr- 

 stenburg can frequently cause the death of goats. This mite has been 

 transmitted to man, horses, sheep, cattle, and pigs. 



The genus Notoedres contains mites causing mange in various ani- 

 mals. N. cati Hering is the cause of mange in cats, which usually starts 

 around the head, forming crusts until the skin becomes hard, thick- 

 ened, and creased like leather. It is usually restricted to the head and 

 neck. The mite has caused mange in dogs. Essi^ 1929 has recorded 

 it as a pest of the wild gray squirrels in California, sometimes even 

 causing their death. Notoedres cati var. cimicidi Gerlach attacks the 

 rabbit, especially around the head, although in serious cases it may 

 extend to the legs and genital regions. Notoedres muris Megnin is 

 parasitic on the common brown rat and may be fatal. Both tame and 

 wild rats are attacked by this mite. 



Knemidokoptes /nutans Robin and Lanquetin causes the scaly-leg 

 of fowl and small domestic birds. Hirst describes it thus: "The large 

 scales of the tarsus of the feet are first affected, becoming raised at the 

 edges by whitish floury powder, which is sometimes mixed with exuded 

 serum. In advance cases the disease assumes a characteristic form, the 

 feet becoming greatly distorted and covered with thick nodular spongy 

 crusts. The comb and neck may also be attacked." Scaly-leg is highly 

 contagious. The depluming itch of poultry is caused by Knemidokop- 

 tes laevis var. gallinae (Railliet). The mites, which are embedded in 

 the tissue or scales at the base of the quills, cause a falling out of 

 feathers over more or less extended areas of the body. It is to be 

 found both in North America and Europe. K. laevis Railliet was de- 



