ANIMAL PARASITES IN POULTRY. 



595 



Railliet, foot mange determined by 8. mutans would be less con- 

 tagious than that of the body produced by b. lœvis. 



In the chicken, foot mange (calcareous tarsa, fish-scale disease), 

 is marked by very characteristic symptoms. It is located upon the 

 tarsa, exceptionally on the comb, or on the fleshy lobes of the lower 

 mandibles and the bill (a contagion which is produced by picking 

 and scratching). At the outset we observe upon the anterior aspect 

 of the extremities small grayish spots which gradually enlarge and 

 soon form rounded indented scabs ; later, the whole surface of the 

 foot is covered with irregular, rugous, grayish-yellow, porous and 

 friable scales, which may reach a thickness of one centimetre, show- 

 ing an imbricated disposition of the different lamellse, which are 

 pearly in appearance and are greasy to the touch. The feet, which 

 are often enlarged and deformed, seem to be coated with lime or 

 clay (calcareous feet). Under the scabs, which are mainly formed 

 of epidermic scales and of dried-up inflammatory exudate, are found 

 the acari ; the skin is red, tumefied, infiltrated with blood and pus ; 

 pruritus is quite intense ; the animals rub and scratch themselves, 

 and pick the scabby covering. When the trouble is old the move- 

 ments are painful and the standing position is often tiresome. 

 Emaciation, cachexia, and even death ensue in serious cases. 



Its treatment is very simple. The scabs must be removed after 

 having been first softened with tepid water ; we then apply one of 

 the following agents upon the diseased surfaces : glycerin, green 

 soap, carbolated or creosotic ointments (1 : 10 to 20) tar, balsam of 

 Peru, styrax, Helmerich's ointment, etc. We must also disinfect 

 the coops and perches. 



II. Symbiotic or rather epidermic mange is generally local- 

 ized on the cervical region and the thorax ; it may, however, spread 

 very rapidly to the whole surface of the body, even to the comb 

 ~ and to the fleshy lobes of the lower mandibles. 



The skin becomes covered with thin, transparent, straw-yellow, 

 stratified epidermic scales, which soon form thick, dirty yellow, 

 hard crusts, similar to dried dough, under which the skin is hyper- 

 emic ; while it does not produce pruritus, this mange leads quite 

 rapidly to weakness and wasting. Many birds die. 



The treatment is the same as that of the preceding trouble. 

 Friedberger observed the coexistence of these two manges upon 

 the same animals. 



Under the name of Sarcoptes oystlcola ( Laiiiinoscoples gallinarum) 



