73f) Paralysis of the Recun-ent Nerve. 



less by a moderate severity of the condition, a draught horse 

 or one that is used at slow paces may last for years. 



In the early stages of the disease difficulty of respiration 

 appears even with severe work only after a long time, thor- 

 oughbreds are capable of running short races without distress. 

 Thomassen's investigations have shown that age is a factor 

 that comes into play, for disturbances are more severe in young 

 animals, presuming the extent of the disease of the nerve to 

 be the same, and also in addition to the paralysis of the mus- 

 cles, marked distortion of the whole larynx is more likely to 

 happen in young animals. 



Treatment. In cases that set in acutely anti-rheumatic 

 treatment or treatment designed to combat acute catarrh of 

 the air jiassages appears to be indicated. 



For the chronic form of the disease, Levi advises intrach- 

 eal injection of strychnine (0.01 to 0.05 gnn. in increasing doses 

 two to three times daily), or Lugol's solution (20 to 30 gm.), but 

 others have not had any results from this treatment. The 

 same applies to the internal administration of preparations of 

 iodine and arsenic. 



Lindemann claims to have had recoveries in many acute 

 cases obtained by repeated partial closing of the nostrils, caus- 

 ing more powerful contractions of the dilators of the larynx. 

 In six cases, Tagg united the recurrent nerve with the vagus and 

 in three cases the roaring disappeared. 



Giinther practiced resection of the sunken arytenoid and 

 of the vocal cord, an operation which was afterwards modified 

 by Stockfleth and Moller. Good results with this operation 

 have been recorded repeatedly, but in a proportion of cases 

 (according to Hirscli in 50 per cent) constriction of the larynx 

 reappears owing to contraction. Hirsch describes arytenoid- 

 ectomy as a very dangerous operation, and one to be consid- 

 ered only when it is a matter of lessening the dyspnea suffi- 

 ciently to permit a horse to carry out its usual work, but it 

 does not do away with the loud respiration. More recently, 

 Blanchard has practiced cricotomy or cricoidectomy, and has 

 cured seventeen animals out of thirty-six.* 



Draught horses may be rendered serviceable by perform- 

 ing tracheotomy and inserting a tube, and this plan may be 

 applied to advantage even to race horses. Tracheotomy also 

 appears to have a beneficial effect upon the disease (Albrecht). 

 Bridles which partly compress the nostrils are not to be ad- 

 vised for although they tend to prevent the noise they impair 

 the animal's power. 



If exact observations provide actual proof of the trans- 

 mission of the predisposition in special cases, it is advisable 

 to cease breeding from the animal transmitting it. 



*Recently the Williams operation for roaring appears to give very good results and 

 extensive statistics show that about 70% of recoveries follow the operation. Hobday reported 

 140 cases operated upon with about 75 permanent recoveries. — (Editors' note.) 



