MANGE, 



563 



flocks) in Alsace-Lorraine. In the last three years, when the 

 German law relative to epizooty was already in force, the official 

 reports have shown, for Prussia alone, 183,000 mangy sheep; for 

 Bavaria nearly 100,000, and Wiirtemberg more than 60,000. The 

 death-rate amounted to about 2000 head in Prussia. For the dis- 

 trict of Greifswald, Furstenberg estimates the yearly loss of wool 

 at 100,000 marks ; this loss amounts to several millions yearly for 

 the whole German Empire. 



Transmission of psoroptic mange is generally by immediate con- 

 tact; a mediate contagion is much less frequent. Contagion will 

 especially take place easily when shorn, mangy sheep are intro- 

 duced into a healthy flock the animals of which have their coat of 

 wool, or ^ben the temperature is high, during the summer, in 

 hot sheepfolds where the animals are crowded against one another. 

 Such conditions favor the activity of acari and their emigration. 



Symptoms. The psoroptes invades the part covered by wool ; 

 other parts (belly, lower pectoral region, head, etc.) remain un- 

 touched. The croup, base of the tail, back, sides of the thorax, 

 neck, and shoulders are the places chosen by the parasites. 



The eruption always commences with small spots, which may 

 be isolated or gathered in groups, according to the mode of in- 

 fection. By spreading the wool apart at the beginning we ob- 

 serve flattened pimples, of the size of a millet-seed, of a pale- 

 yellow or reddish color, which are produced by the bites of the 

 psoroptes. According to the number of the latter, we find the 

 papules disseminated or agminated, forming in this latter case 

 flat pimples, which may reach the size of a silver dollar ; the skin 

 of the neighborhood is red, and sensitive to the touch. On the sur- 

 face of the pimples small vesicles or pustules appear which tear 

 or dry up ; an abundant epidermic desquamation is produced at 

 the same time, which forms thick crusts by becoming mixed with 

 the sebaceous matter and with the contents of the pustules ; these 

 scabs are sometimes very hard and of a yellow-brownish color; 

 they protect the parasites. The scabs become shrivelled and 

 parchment-like upon the diseased shorn skin. The remaining 

 bits of wool are at first agglutinated by the liquid of the pus- 

 tules; soon they form scabby masses and detach these from the 

 skin ; their roots are loosened ; the fleece gradually becomes flaky : 

 more or less large numbers of tufts appear on its surface and fall 

 out or are torn out ; the wool has lost its lustre and its softness ; it 



