DISEASES WHICH ARE INDUCED BY PARTICULAR PARASITES 165 



off short at the mouth of the follicle, owing to their brittle condition; and 

 another form, in which the scabs are yellow, and the hairs, instead of 

 breaking off, fall out and leave perfectly bare patches of skin. This variety 

 of the disease does not appear to have been recognized in England. 



Treatment. It is a somewhat remarkable character of this disease 

 that while the eruption extends from the centre of the scab by constant 

 distribution of the spores there is a well-defined limit to its progress, 

 and at a certain point the disease undergoes a spontaneous cure. This 

 has been noted particularly in ringworm of calves, arid there is no doubt 

 that the continuance of the affection in many cases is largely depen- 

 dent on the general weakness and poor condition of the subject. The 

 average duration of ringworm in the horse is said to be forty to fifty days, 

 but it must be understood to mean that in regard to a certain spot or 

 a certain number of spots a cure will be evident by the growth of new and 

 healthy hair. Meanwhile, however, any advantage from this spontaneous 

 cessation of the affection is often neutralized by the constant conveyance 

 of the spores (seeds) of the fungus to the other parts of the skin. Con- 

 sequently it happens that as fast as the affection is cured in one place it 

 breaks out in another; hence the necessity for the prompt use of remedies 

 which will destroy the vitality of the fungus as quickly as possible. 



Various agents are employed in the treatment of ringworm, and it may 

 be said of nearly all of them that they are perfectly successful, for, unlike 

 the ringworm of the human subject, ringworm in the lower animals is not 

 difficult to cure. Among the agents which are recommended are a solution 

 of corrosive sublimate, 1 to 300 of water, to which a little spirit has been 

 added, or a mixture of 1 part carbolic acid with 10 parts of glycerine. 

 These preparations are to be applied by means of a brush to the spots 

 of ringworm wherever they are found. Of the ointments which are com- 

 monly employed, blue mercurial ointment, and red biniodide of mercury, 

 each diluted with six times its bulk of lard or vaseline, are most effective. 

 The treatment in any case will have to be continued until a healthy state 

 of the skin is indicated by the growth of new hair in all parts of the 

 diseased skin. 



Transmission of ringworm to other horses, probably also to other 

 animals, and certainly to human beings, is likely to take place unless 

 proper precautions are used. Care therefore should be taken to cleanse 

 and disinfect thoroughly the stable and its fittings, destroy the litter, and 

 disinfect or destroy all the stable apparatus used about the diseased 

 animals. 



For the protection of the helper who dresses the animal the shirt-sleeves 

 should be kept down instead of being turned up, as is usually done, 



