DEHORNING OF CATTLE 41 



The point for excision is located on the cephalic side of 

 the matrix of the horn, a distance of about i to 1.5 cm. 

 from the margin of the skin. There are three reasons for 

 selecting this location : 



1. It is essential to include a girdle of skin of the width 

 named in order to remove the matrix of the horn. If less is 

 removed, horn is developed and the animal is left with un- 

 sightly horny excrescences. 



2. The chief arteries of the horn core (extension of 

 frontal bonej are at this point subcutaneous, can conse- 

 quently retract readily and thereby exert efficient hemosta- 

 tic power. They soon leave the subcutem and become 

 intra-osseous as shown in Fig. 12 at 1,2 and Fig. 13 at i, 2. 

 The intra-osseous artery, when severed, cannot retract 

 promptly and therefore possesses low hemostatic power, 

 resulting frequently in severe, and rarely in fatal, 

 hemorrhage. 



3. The horn is more ea.sily excised at this point than 

 elsewhere. If the excision is attempted through the corne- 

 ous layer instead of at the point indicated, the horn tissue 

 offers great resistance. The application of great force to 

 overcome the undue resistance may cause extensive fracture 

 of the horn core, or may bend or break the blades of the 

 dehorning instrument. 



The blades of the dehorning shears should be kept sharp 

 and in good condition. Dull blades fracture the horn core 

 and thus delay healing, and the dullness, by increasing the 

 strain, tends to break the instrument. 



Have an assistant grasp the nose firmly by means of a 

 leading ring or with the fingers and steady the head. Apply 

 the dehorners at that point level with the base lineofi,in 

 Fig. 12 and close them promptly, completely excising the 

 horn. Free bleeding generally follows but if the excision 

 is made at the point indicated, the divided arteries contract 

 and the hemorrhage quickly ceases. As shown in Fig. 12, 



