LAMENESS IN THE HIND LEG 225 



(perforatiis), there remains nothing to inhibit tarsal flexion 

 except the deep flexor tendon (perforans) and this does not sup- 

 port the leg. When attempt is made to sustain weight with the 

 affected member, abnormal flexion of the tarsus takes place and 

 the hock sinks almost to the ground. The symptoms are so char- 

 acteristic that recognition is always easy even in case no wound 

 of the skin exists. 



Prognosis. — Spontaneous recoveries occur and such cases 

 are reported by Bouley who is quoted by Cadiot as having ob- 

 served division of the tendo Achillis due to a sword wound 

 wherein at the end of four mouths recovery was complete. Di- 

 vision of this tendon in brood mares has been practiced by the 

 early settlers of parts of the United States for the purpose of 

 preventing their straying too far from home. In such instances 

 one leg only was so mutilated and in most instances, it is re- 

 ported that spontaneous recovery took place. 



In unilateral involvement without complications, the prog- 

 nosis is not unfavorable if provisions for giving necessary atten- 

 tion are available. 



Treatment.— Tlie subject is to be confined in a sling and the 

 member bandaged and supported by means of leather splints. 

 Immobilization as for fracture is not necessary but, nevertheless, 

 movement is to be restricted as much as possible. In case of 

 open wounds, tiie exposed tissues are cared for along general 

 surgical lines. Where the divided parts of the tendon are main- 

 tained in fairly close and constant relation, granulation of tissue, 

 sufficient to sustain weight takes place in from six weeks to three 

 months. 



Spring-Halt. ( String-Halt. ) 



Occurrence. — This condition is a myoclonic affection of the 

 hind leg which is discussed in works on theory and practice 

 under the head of neuroses, but the cause or causes have not 

 been established. Theories that heredity is responsible have 

 their supporters and advocates of hypotheses attributing it to 

 disease of the sciatic nerve, patellar subluxation, fascial con- 

 traction of various muscles, "dry spavin" (tarsal arthritis), 

 iliac exostoses, disease of the foot and contraction of the hoof. 



