150 HORSESHOEING. 



this reason a shoe with heel-calks is never advisable if an open 

 flat shoe without other means of relief can be used. Further- 

 more, since contraction is the parent of nearly all diseases of the 

 hoof (corns, quarter-cracks, bar-cracks, thrush of the frog), we 

 should use the greatest care to prevent it by dressing the hoof 

 as described on pages 83 to 87, using flat shoes with a horizontal 

 bearing-surface for the quarters, giving abundant exercise, 

 preventing drying out of the horn, and allowing the animal to 

 go barefoot whenever possible. 



Where the contraction is but slight the foregoing rules will be 

 found sufficient. In very pronounced contraction, where the hoof 

 is not acute-angled, an expansive shoe with clips raised at the 

 ends of the branches to press against the buttresses may prove 

 very advantageous ; but under no conditions should violence be 

 used in expanding the heels with the expanding-screw. This 

 act should be performed only by experienced veterinarians. 



For contracted hoofs of the acute-angled form we use the bar- 

 shoe, and if there are other diseases of the hoof present, or if we 

 wish a more rapid and continuous expansive action, we use also 

 a leather sole with foot-packing. A foul frog should be properly 

 cleansed, and then disinfected with pine-tar thinned with alcohol 

 or crude wood-vinegar (pyroligneous acid). 



Further curative measures are : turning the horse out without 

 shoes (expensive and seldom practicable) ; applying tips ; using 

 shoes the bearing-surface of whose branches inclines downward 

 and outward (unilateral contraction requires but one branch to 

 be so constructed) ; hoof-pads of rubber (Hartmann's pad), straw, 

 rope, cork, hoof-cement, etc. Special forms of contraction are 

 distinguished, and are as follows : 



(a) The Contraction of Wide Hoofs. — This contraction is man- 

 ifest as a concavity or groove in the wall just below the coronet, 

 usually at the quarters, though sometimes extending entirely 

 around the foot parallel to the coronary band. Pain is produced 

 in the contracted area by lightly tapping the horn, but not by 

 moderate pressure with the hoof-testers. 



