ABERRATION OF THE APPETITE. 



63 



The observations of Vath, Gassner, and Ostertag^ concerning 

 the efficiency of apomorphine are, very favorable. Hafner, how- 

 ever, has mentioned one unsuccessful case. 



We shall say but few words on licking-disease in the pig and 

 the horse. 



1. We must not mistake it, in the pig, for osteomalacia. Some- 

 times both affections coexist.^ 



Spinola states that the disease is observed in the pig, in coun- 

 tries where it is common in the ox ; it also resembles the latter in 

 its course, its duration, and its ending. The sick pig shows a 

 special craving for decayed peas and tree bark. 



2. Horses, and particularly young ones, are sometimes affected. 

 The patients lick and bite the surrounding objects constantly ; they 

 refuse part of their ration in order to eat their litter, even the 

 manure. There are, however, but few isolated cases found among 

 this species, and it is probably due to gastric trouble. We observe 

 a caprice in many young horses which must not be mistaken with 

 licking; we refer to the habit in the young, of eating the mother's^ 

 tail and mane. 



We have seen licking disappear rapidly in a young horse which 

 was given lime-water; Lippold^ has seen in the adult horse a 

 morbid condition similar to licking-disease. 



2. Wool-eating" Sheep (Mallophagia) ( Wollefressen). 



This affection is of the same nature as licking-disease. The 

 harm done to wool, the loss which results from it, and the mor- 

 tality it occasions among lambs, give it a certain importance from 

 an economical point of view. 



Etiology. The recorded opinions upon the etiology and nature 

 of the affection now to be described are quite as diverse as those 

 which have been advanced concerning the morbid condition last 

 mentioned. There are two principal theories : in the first, the 

 affection is looked upon as the result of imitation ; in the second, 

 it is ascribed to diseases of nutrition. At the present time it 

 it would be arbitrary to exclajie either in an absolute manner. 

 Both incriminated causes, it would seem, take a certain part in the 

 production of the disease. 



1 Vath, Gassner, and Ostertag (unpublished communications). 



2 Jansen: Preuss. Mittheil., 1873-74. 

 * Lippold : Sachs. Jahresber., 1883. 



