14 MANUAL OF POISONOUS PLANTS 



pasture, the new condition being opposed to contagion. In the case J of the cat, 

 early age seems to be an essential condition. In the case of the rabbit, a 

 similar condition seems to hold true. In the dog, early age is not an especially 

 predisposing influence but inoculation is successful in young dogs only, accord- 

 ing to Horand, so far as trichophyton is concerned. This latter statement does 

 not hold true for favus. 



Contagion. In ringworm of the horse, infection may occur from horse 

 to horse. Megnin states that in one locality 200 horses became in- 

 fected in this way, a saddle from an infected horse having carried the 

 disease to other animals. In each case, the disease occurred on the left 

 side of the back. It has also been transmitted from an ox to a horse. The 

 tinea tonsurans has been transmitted from the horse to calves, and the tinea of 

 the horse from horse to dogs, sheep, and pigs, and even to man. Neumann 

 says : "The infection of man is exceptional when the frequency of tinea ton- 

 surans in the horse is considered, as there is scarcely a regiment in which it is 

 not always on some young horse." Grooming is the usual way in which the 

 infection is carried and rubbing facilitates inoculation. The ease with which 

 infection occurs on man depends on the character of the fungus, some forms 

 adapting themselves to the conditions present more readily than others. In the 

 case of the bovines, the contagion may be direct. The virus may be preserved 

 a long time in parts of stables where calves were affected with the tinea 

 tonsurans. The infection spreads less readily to sheep and pigs but may be 

 transmitted from bovines to man. In the case of the dog, it is transmitted from 

 dog to dog, from rats and mice to the dog, and, occasionally, from dogs to man. 

 In cats, favus is largely transmitted from mice and it is certain that this form 

 can be transmitted to man. In general, it may be said that the transmission of 

 favus from the rat or mouse is frequently brought about through the domestic 

 cat. The tinea of the fowl is transmitted by contact with a diseased fowl. The 

 favus fungus of the fowl * cannot be inoculated on the rat or dog but when 

 inoculated on man, it produces lesions similar to favus. Man may be inoculated 

 very easily by handling a fowl on which large erythematous patches occur. 

 Similar patches have occurred in man when inoculation from a fowl was very 

 probable. 



Symptoms. Two forms of skin dermatomycosis in the horse have been 

 recognized: (1) called microsporosis, and (2) trichophytosis. The more 

 important symptoms of the first as given by Neumann are: "It appears 

 in patches which are more especially seated on the upper part of the 

 body on the shoulders, back, loins, croup, sides, and flanks. These patches 

 may, however, be met with on any part of the body, though they are rare on 

 the lower parts of the legs. What are first noticed are the circular patches, the 

 diameter of which is generally about that of a shilling; they are distinguished 

 from the healthy skin by the dullness and erectness of the hairs covering them. 

 Some time before the circular patches appear, a very small tuft of hairs 

 probably from half a dozen to a dozen may be seen slightly, but markedly, 

 raised in the form of a fine pencil, and feeling as if they had a somewhat 

 hard base, or were matted together at the bottom, when the finger is passed 

 over them. These tufts may be several in number, and are usually best seen 

 in hindquarters at the very commencement of the disease, or in the vicinity 

 of the patches, of which they are the initial symptom. The hairs fall off in a 



1 Lophophyton gallinae, Megnin Trichophyton Megnini, Blanchard. Sporotrichum. 



