HORN TUMOUR. 213 



the teetli closely resembles that of liorii, hair aud cuticle (scarf- 

 skin or outer skin); all being forms of epidermal growth (p. 

 154V 



The CAUSE is generally injury, as for instance ''tread" when 

 the growth has begun at the coronet ; or the act of hammering 

 down clinches of the nai's or clips of a shoe ; ijr puncture of, or 

 pressure on the sensitive lamin:u by an ill-directed nail. 



I'he usual SYMPTOMS are : lameness, which may come on verv 



4i, 



Fig. 71. — Shoe with toe turned up on ground surface, but flat on foot surface. 



gradually ; pain on tapping the part ; and local heat. Tlie lame- 

 ness of a horn tumour at the toe is similar to that of chronic 

 laminitis. If the tumour begins at the coronet, it will usually 

 cause the horn of the wall which covers it to bulge outwards. 



TREATMENT. — Cut down on the tumour from the outside of 

 the wall of the hoof ; poultice the part for two or three days ; 

 remove the tumour with a pair of pincers, aiding the operation 

 with the knife; and treat the wound antiseptically (p. 69). If 

 the bone be affected, it may have to be scraped to remove any 

 dead parts. The cavity may be dressed like that of seedy-toe (p. 

 202). The disease is very liable to recur. 



