280 VETERINARY SURGICAL THERAPEUTICS. 
the second phalange, constitutes an obstacle to the free movement of 
the phalanges and produces the springhalt. Chénier thinks that spring- 
halt is due to a lesion of the intra-horny tissues generally to pain or pres- 
sure taking place at given moments of the walk. To back his opinion, 
he says that horses that have cracks in the toe or the mamme of the foot, 
or that have deformities of the hind feet, as in laminitis, do frequently 
have springhalt. He remarks that the symptoms diminish by exercise, 
as the tissues of the foot become accustomed to the painful irritations, 
and that if the disease were seated in muscles, tendons or aponeurosis, 
the irregularity of action would increase by work. 
Like Gunther, many authors (Dieckerhoff, Bassi, Trasbot, Weber, Chu- 
chu, and Moller) admit to-day that springhalt is a symptom of a great 
many different lesions. With Moller, springhalt can be divided into 
idiopathic (without visible occasioning cause) and symptomatic, when due 
to lesions of various nature and seat (bony diseases of the hock, scratches, 
blows, seams, laminitis, quittor, keraphyllocele, canker). , 
In fact, springhalt is always a secondary symptomatic affection. The 
spasmodic contractions which essentially characterize it are of a reflex 
order and promoted by lesions very diversified in their nature and localiz- 
ation, sometimes visible and at other times incapable of diagnosis, and 
often incurable. 
Let us see now the forms of treatment recommended for it. We will 
speak only for memory’s sake of the antispasmodics (belladonna, aconite, 
stramonium) used by Renner to overcome “the spasm of the posterior 
crural muscles.’ Vachetta has had some success with acupuncture and 
irritating frictions on the biceps femoris and semitendinous muscles, which, 
according to him, are in process of atrophy. But little can be expected 
from blisters or firing of the hock. 
Some authors who, like Percivall, Lafosse and Merle, admit a nervous 
lesion, have tried the resection of the anterior tibial nerve, the principal 
branch of the small femoro-popliteal nerve. The operation is easy: The 
horse having been cast on the side opposite to the diseased leg, the opera- 
tor, placed behind this leg, incises the skin parallel to the tibia on the 
external side of the superior extremity of the bone, where the nerve, 
easily found, runs in an oblique direction downwards and forwards. A 
second stroke of the bistoury divides the tibial aponeurosis, and the nerve, 
very near the surface there, is immediately exposed. The following 
steps are those of all nervous resections. This neurotomy has never 
given very satisfactory results. 
The section of the great sciatic nerve (posterior tibial nerve) above the 
hock, succeeds when the lesions are seated in the inferior parts of the leg. 
(See Tendinitis.) 
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