MANGE. 



565 



especially inform ourselves concerning the condition of the integu- 

 mentary membrane covering these regions : base of the tail, croup, 

 back, and shoulders ; it is sufficient to spread the wool apart in 

 order to recognize the alterations of the integument; we may judge 

 of the degree of its sensitiveness by scratching. We must also 

 look for any coloration of the wool resulting from drugs used by 

 the shepherds. 5. A microscopic examination and finding of the 

 psoroptes alone permit us to decide the nature of the trouble with 

 certainty. 



Differential diagnosis. The affections which we may confound 

 with psoroptic mange are : 



1. Hain rot This is an eczematous disease, which is produced 

 by prolonged dampness of fleece and skin ; it is sometimes observed 

 upon a large number of animals of one flock, exactly like mange. 

 A difference may be made by the pathology of this dermatosis, by 

 its rapid disappearance as soon as the weather becomes favorable 

 or when the animals are kept in the sheepfold ; also by the slight 

 intensity of the alterations of the skin and the absence of pruritus. 



2. Other cutaneous parasitic eruptions produced by melophages 

 and trichodectes. It is sufficient to examine the wool and skin 

 carefully, in order to be immediately informed. 



3. The abnormal production of ^' yolk^^ (wool fat) and its accumu- 

 * lation in the fleece. In this affection the bits of wool are agglu- 

 tinated and some pruritus exists, but the skin is clean and smooth, 

 soft, and free from any lesion. 



4. Cauterizations of the skin, made with fraudulent design. They 

 may be recognized by the abnormal coloration which the caustic 

 has left upon the wool and skin, or by the characters of the scab ; 

 in some cases, however, this has truly the aspect of mange scab. 

 The course of the disease and the microscopic examination give 

 more precise diagnostic information. 



Treatment. We have the choice between two principal methods, 

 frictions and baths. The former constitute a kind of provisory 

 treatment, which is used either as a preparation for baths, or at 

 times when baths cannot be given (cold weather). We apply 

 ointment or liniments on the circumscribed mangy centres (car- 

 bolated soap or oil, mercurial ointments, decoction of tobacco, 

 petroleum, etc.). These frictions cannot produce a radical cure, 

 for they only reach the appearing centres, which are more or less 

 old ; the others, which are of recent date and disseminated on the 



