POULTRY DISEASES AND THEIR TREATMENT. 1 35 



Another spray successfully used is : 3 parts kerosene and i 

 part crude carbolic acid. Still a third, kerosene emulsion is 

 recommended by the United States Department of Agriculture. 

 Their method of making this spray as given in Circular No. 92 is 

 as follows : '"To make this, shave y^ pound of hard soap into i 

 gallon of soft water and boil the mixture until the soap is dis- 

 solved. Then remove it to a safe distance from the fire and 

 stir into it at once, while still hot, 2 gallons of kerosene or coal 

 oil. The result is a thick, creamy emulsion. Dilute this stock 

 mixture with 10 parts of soft water, and apply as a spray or 

 with a brush, being careful to work it into all cracks, crevices, 

 and joints of the building." 



With any of these sprays it is necessary to make two or more 

 applications at intervals of a few days to destroy the mites 

 which hatch after the first application. The liquid may be put 

 on with a hand spray pump or with a brush. Cleanliness, fresh 

 air and sunlight are cheap and effective preventatives. 



Scaly Leg. 



A minute mite, Knemidocoptes (Dermatoryctes) (Sarcoptes) 

 mtitans, is the cause of a contagious disease affecting the legs 

 of fowls, turkeys, pheasants, partridges and cage birds. Ac- 

 cording to some authorities it sometimes affects the comb and 

 beak also. The mites excavate places under the skin where they 

 live and breed. The most thorough study yet made of this para- 

 site and its effect on birds is that of Haiduk.* 



Diagnosis. — This very common disease is easily recognized by 

 the enlarged roughened appearance it gives the foot and shank. 

 This appearance is shown in fig. 29, with a normal leg for com- 

 parison. 



The disease is present in most flocks unless especial care has 

 been taken to exclude it. It is slightly contagious, but usually 

 only a few birds in a flock appear to be infected. The (scales 

 on the foot and leg of an affected bird are raised by a crusty 

 substance ..cposited beneath them. The lesions usually appear 

 first neai the joints between the toes and foot. The parts affect- 

 ed first appear to be enlarged and then the scales are raised, 

 giving the roughened appearance shown in B fig. 29. In early 



*Haiduk, T. Die Fussrauder des Gefliigels. Inaug. Di.ss. Giessen, 

 1909, pp. i-s8, Taf, I- VI. 



