4IO Veterinary Medicine. 



dition which lowers the general tone of health strongly predis- 

 poses to an attack. The same remark applies to irregularities- 

 and faults in feeding. The best food and the most abundant 

 supply will fail under such circumstances to maintain the con- 

 dition, and the horse that is losing condition is becoming increas- 

 ingly susceptible to this malady. 



The period of dentition and training is the most common 

 occasion for the attack, partly because this is the time when the- 

 colt is taken from the pure air and exercise of the field, into the- 

 hot, close, impure atmosphere of the stable, partly because he- 

 is made to exchange the cooling succulent grass for the stimula- 

 ting ration of hay and grain, partly because he is subjected to- 

 severe constraint and much excitement in the hands of the trainer, 

 and partly because of the irritation of the gums, the jaws and 

 the whole head in connection with the shedding and eruption of 

 the teeth. When injudicious bitting is resorted to, to give a 

 special curve to the neck, the consequent obstruction of the 

 jugulars and capillary congestion in the head is another potent 

 cause. Heavy draught and overdriving have a similar effect. 

 In 53 cases Schmidt found that 3 occurred under one year old,. 

 5 in the 2d year, 10 in the 3d year, 16 in the 4th, 15 in the 5th, 

 and 4 from the 5th to the 9th years. 



Influence of Season. Mayer gives a statement of the per- 

 centages seen in the various months of the year as follows : 

 January 4.9%, February 4.7%, March 10.1%, April 15.1%, 

 May 13.4%, June 9.9%, July 11.9%, August 6.4%, September 

 4.9%, October 6.2%, November 6.7%, December 5.2%. The 

 high rate in March, April and May may have a significance in con- 

 nection with the debility connected with shedding the coat, and 

 the resumption of more active work, when somewhat out of con- 

 dition, it must also be noted that this is in Germany the season 

 of the most active trade in horses and con.sequent change of 

 ownership, stabling, feeding, work and management. 



Heredity must be accepted as one of the most potent accessory 

 causes. The lymphatic constitution is of course transmitted and 

 with it the special susceptibility. This is notorious in the case 

 of both parents, and is of course more potent if both sire and 

 dam were predisposed, and have themselves suffered. In the- 

 latter case the heredity of the lymphatic temperament, and of the 

 impaired organ of vision combine to render transmission more 



