HERPES TONSURANS 483 



Symptoms. Ringworm occurs in all small animals but 

 is most common in the dog. The lesions may be found on 

 any part of the skin but usually appear on the head and 

 legs, parts frequently in contact with objects harboring the 

 parasite. 



Ringworm is characterized by small, well defined, circular 

 areas. By increasing in size and number they merge to 

 form irregular, large patches. At first slightly reddened, 

 these areas soon are covered with dirty, gray crusts or 

 scabs. Irritation is variable, at times very intense inducing 

 scratching and rubbing which remove the crusts and leave 

 the surface raw and bleeding. Small nodules are some- 

 times seen, due to swollen hair follicles. Most of the hair 

 is broken off. On those areas where pruritus is absent the 

 crusts remain, become thicker and agglutinate the hairs. 

 Suppuration proceeds beneath the crusts and an offensive 

 odor is emitted. In general the condition is less severe and 

 more superficial than sarcoptic scabies, but the spread is 

 more rapid. When the condition involves a greater part of 

 the body general disturbance follows. Suppuration beneath 

 the scabs permits of the absorption of toxins which poison, 

 and the constant irritation exhausts the animal. 



Diagnosis. Accurate diagnosis is possible only with the 

 microscope. The well defined, circular areas covered with 

 short hairs in most cases and the rapid progress may be indic- 

 ative. 



Prognosis. Very good if treated before the animal becomes 

 emaciated and exhausted. Spontaneous recovery is exceed- 

 ingly rare. 



Treatment. In a generalized case, except in short haired 

 animals, remove all of the hair. Where only isolated spots 

 occur clip the hair well back from the margin. Remove the 

 crusts, softening them if necessary with lard, oil or ointments. 

 Cleanse the skin by washing with a soapy or alkaline (sodium 

 carbonate) solution. 



This parasite is not very resistant, hence most of the anti- 

 parasitic preparations give good results. Inasmuch as the 

 fungus is somewhat susceptible to fats the medicinal agents 

 should be applied in oils or ointments. These prevent fur- 



