478 PARASITIC SKIN DISEASES 



with dirty yellow crusts. Crusts also form on the plantar 

 surface of the feet and at the root of the claws which become 

 swollen and distorted. To relieve the intense itching the 

 animal frequently scratches and bites itself, at times gnawing 

 the feet so viciously that they become severely wounded. 

 Walking is difficult, the weight being thrown on posterior 

 parts of the foot. A disagreeable odor is exhaled from the 

 animal. 



Sarcoptes Mite of the Fowl (Cne7nid0c0pt.es mutans, Sarcoptes 

 mutans, var. gallium) . —These parasites burrow under the scales 

 on the featherless parts of the skin of the feet and legs. The 

 resulting exudate elevates the scales and there is a formation of 

 a white granular matter agglutinated by the exuded serum. 

 Irregular masses of crusts separated by fissures continue to 

 form and usually involving all of the skin on both legs. They 

 are firmly adherent and when detached leave the skin raw 

 and bleeding. The crusts become of a soft, spongy consist- 

 ency due to the numerous furrows excavated by the parasite. 

 Movements of the joints aggravate the condition; walking 

 and even standing are difficult and painful. Occasionally 

 an entire toe may drop off. The course of the disease is 

 slow, the fowls become emaciated and finally die from 

 exhaustion. 



Diagnosis.— An accurate diagnosis is possible only by a 

 careful microscopic examination. Otherwise sarcoptic mange 

 may be mistaken for many other diseases of the skin. It is 

 essential to detect and identify the parasite before a correct 

 diagnosis can be made. 



Prognosis.— Mild cases with local lesions only may be 

 treated with very good results. This is especially true in 

 cats. ' Severe cases, where the process affects the entire skin 

 surface, are almost incurable especially if symptoms of 

 emaciation and exhaustion are present. 



Treatment.— It is necessary to remove all the hair coat, if 

 long. A possible exception ihay be made when the disease 

 is strictly localized as in cats. Cleanse the skin and remove 

 all scales and crusts by using an alkaline wash (sodium 

 carbonate 2 per cent., or soapy water) applied with a fairly 

 stiff brush. However, indiscriminate brushing should be 



