142 PARASITIC SKIN DISEASES. 



respectively put. It can be communicated from horse to man, 

 and vice versa; though not with anything like the same facility 

 as from horse to horse. It is much less severe in horses than in 

 human beings. The parasites, away from their hosts, aswhen they 

 liave got into the panel of a saddle, will retain their vitality for a 

 Ipng time, certainly over six months, under favourable conditions. 



SYMPTOMS. — Tinea tonsurans derives its name from the shaven 

 appearance presented by the attacked portions of skin. It spreads 

 by more or less circular patches which have a well-defined border, 

 and commencing, say, with a diameter of from half an inch to an 

 inch, do not usually exceed that of two inches. The affected patch 

 of skin becomes bald (as if shaven) by the hairs breaking off close 

 to the skin. The denuded surface as a rule presents but little sign 

 of irritation beyond the fact of small scarf-skin scales being found 

 on it. The elevated and inflamed condition of the border of the 

 invaded patch of skin seen in cases of ringworm in man, is absent, 

 or nearly so, in the horse. There is little or nO' itchiness. When 

 this fungous growth has attained its full extent, which may be put 

 down as a general rule, at two inches, it seems to die, and the 

 hairs grow again as before, except that, for some time, their colour 

 is darker, and they are drier and more erect than usual. Ring- 

 worm spreads from separate centres, usually infected by the seeds 

 of the disease being carried from one or more previously diseased 

 spots in the same animal, and which may run into each other. It 

 is found on various parts of the body (Fig. 46). 



TREATMENT.— After washing the affected parts well in the 

 manner described on page 139, apply either (1) or (7) recommended 

 on page 140 for mange, once or twice a day as the case may 

 demand. 1 part of salicylic acid mixed with 6 parts of lard may 

 be used with invariable success, and without irritating the skin. 

 I have had cases of ringworm which got well merely by good 

 grooming. In South Africa, biniodide of mercury ointment (1 

 drachm to 4 oz. of vaseline or prepared lard) has always given 

 good results. In human practice, 1 part of thymol to 18 parts of 

 paraffin oil is an excellent, application. A saturated solution of 

 common salt is generally efficacious. The destruction of the para- 

 site will be shown by the hair growing on the previously denuded' 

 spots. Constitutional treatment, by tonics and special articles of 

 food, appears to have no influence. Removal of the parasite is the 

 only treatment required. 



DISINFECTION (p. 141) should be applied to the grooming 

 utensils, saddlery and harness, the lining of which, in such in- 

 stances of infection, will generally harbour the parasite. 



