QFITl •^R- THRUSH. 401 



tormed, go that no matter shall be confined, but it shall be. allowed 

 to come away as fast as it forms. This can only be done by prob- 

 ing; and if the original opening is in the coronet, the probe must 

 be passed down as low as possible, and then the sole should be 

 pared away till the end can be reached. In tolerably recent quit- 

 tors, this plan alone will allow the sinus to heal ; but in old ones, 

 the internal surface has become callous, and no granulations are 

 thrown out. Here an injection should be thrown in every day 

 with a syringe, a saturated solution of sulphate of zinc being that 

 generally recommended ; but I have found the chloride answer 

 still better, using one drachm of the salt to a jpint of water at first, 

 and going on up to two drachms. By injecting this daily, and in- 

 troducing a piece of lint, wetted with it, into the superior opening, 

 leaving the lower one free, I have cured many bad quittors, even 

 when there was evidence of caries of the coffin-joint. The disease 

 requires a careful adjustment of the remedies to its extent and 

 nature, and a theoretical description of it is of little use. 



THRUSH. 



Any offensive discharge from the frog is called by this 

 name, although the cause and treatment may be as different as 

 possible. It varies greatly in the fore and hind feet; and, indeed, 

 it must never be forgotten that, in every case, the cause which 

 has produced the discharge must be clearly made out before anj 

 plan of treatment can be carried out with any prospect of success 

 Sometimes thrush is merely the result of the decomposition of the 

 horny frog, from the foot being constantly kept wet with urine, 

 which is most common in the hind foot. Here the surface becomes 

 soft, and is gradually dissolved; while the cleft, from its retaining 

 the moisture, is increased in size. This state is often brought on 

 by the too frequent use of cowdung-stopping in horses with soft 

 frogs; and, instead of doing good by his treatment of the foot, the 

 groom is really destroying it by encouraging the decomposition of 

 the healthy defence which Nature has given to it. For this kind 

 of thrush, very little treatment is required, if the cause which 

 produced it is withdrawn. Still it is not always easy to keep the 

 frog dry, and stop the decomposition, without the application of 

 some astringent ; and if the mere use of dry litter, and the appli- 

 cation of tar ointment, do not seem to harden the frog at once, it 

 may be touched with a wash composed of ten grains of bluestone 

 to the ounce of water. This will soon dry it ; or, if it fails by any 

 chance, the chloride of zinc may be used in the same way, by 

 dissolving five grains in an ounce of water. 



The second kind of thrush is that in which from a gross 

 habit of body there is a simple inflammation of the sensible frog, 

 and instead of sound horn being secreted, a spongy substance is 

 84 * 2 c 



