76 LAMENESS IN THE HOESE. 



easily made thau the bar-slioe. lu case both feet are 

 affected at the same time, diagnosis often becomes 

 exceedingly difficult, and main reliance should be placed in 

 palpation. A good deal of discretion is required, as the 

 animal experiences pain by standing upon one leg, which is 

 necessary during the examination ; therefore his attempts to 

 draw away the foot to be examined cannot always be looked 

 upon as pain resulting from the hoof-testers, etc. 



Differential Diagnosis: 1. Sesamoid Lameness. — Careful 

 examination of the region of the sesamoids is sufficient to 

 avoid errors. (See page 66.) 



2. Thrush. — In bad cases of thrush, where the greater 

 part of the frog is diseased, a supporting-leg lameness is 

 sometimes produced, which in some respects resembles 

 navicular lameness. In thrush, volar flexi<"i of the 

 phalanges and forward pointing are not so persistent as in 

 navicular disease. In severe forms of thrush, lameness, 

 more acute on soft than on hard and level ground, with a 

 tendency to increase when working, is apparent. Pressure 

 upon the diseased frog with the hoof-tester must be done 

 carefully and slowly, as less piessure is required to produce 

 pain in thrush than in navicular disease. In doubtful cases 

 it is advisable to practice forced dorsal flexion of the 

 phalanges, which, as alread}' stated, usually causes pain in 

 true navicular disease, but not in thrush. 



3. Sprain of the Posterior Liyamenis of tlie Coronet Joint. — 

 The examination of the horny box and its contents with the 

 hoof- tester is painless ; but palpation of the region of the 

 posterior ligaments of this joint will in all probability locate 

 pain and perhaps swelling of the ligaments in question. 

 Lameness resulting from sprain of the posterior ligaments 



