404 



of the foot results from an interference with the return flow of blood, 

 which is being sent to these organs in excess. These are more apt to be 

 simple cases of congestion, soon to recover, yet they may become true 

 cases of laminitis. Youatt says : " The danger is not confined to the 

 change from heat to cold ; a sudden transition from cold to heat is as 

 injurious, and therefore it is that so many horses after having been 

 ridden far in frost and snow and placed immediately in a hot stable and 

 littered up to the knees are attacked by this complaint." I have never 

 seen the disease occur under exactly similar circumstances, but am in- 

 clined to believe that in these cases the disease was attributed to the wrong 

 cause — the excitement, exhaustion, and concussion of the long ride being 

 apparently entirely overlooked. Furthermore, if we consider the phys- 

 ical conditions which must necessarily be present under the circum- 

 stances, it seems inconsistent with our knowledge of the effects of heat 

 and cold to believe that the very moderate temperature of stables and 

 the heat-producing properties of bedding " up to the knees" could be pro- 

 ductive of laminitis. Rather should we say that such favorable cir- 

 cumstances would be conducive to opposite results. 



(5) Why it is that certain kinds of grain will cause laminitis does 

 not seem to be clearly understood. Certainly the\' possess no specific 

 action upon the laminae, for all animals are not alike affected, neither 

 do they always produce these results in the same animal. In the case 

 of some of these ailments, where their ingestion causes a strong ten- 

 dency to indigestion, the consequent irritation of the alimentary canal 

 may be so great as to warrant the belief that the laminte are affected 

 through sympathy. In other instances there is no apparent interfer- 

 ence with digestion, nor evidence of any irritation of the mucous mem- 

 branes, yet the disease is in some manner dependent upon the food in 

 question for its inception. Barley, wheat, and sometimes corn are the 

 grains most prolific in the production of this disease. With some horses 

 there appears to be a particular susceptibility to this influence of corn. In 

 such instances the feeding of this grain for a few days will be followed 

 by inflammation of the feet, lasting from a few days to two weeks time- 

 In these animals, to all appearances healthy, the corn neither induces 

 colic, indigestion, nor purging, and apparently no irritation whatever 

 of the alimentary canal. 



(G) Fortunately purgative medicines but rarely become the exciting 

 cause of inflammation of the laminaB. That it is then the result of a 

 sympathetic action upon the part of the tissues affected is no doubt 

 more than hypothetical, for when there is no derangement of the ali- 

 mentary canal existing a dose of cathartic medicine will at times bring 

 on severe laminitis, and that, too, before purgation commences. 



(7) Most if not all the older authorities were agreed that metastatic 

 laminitis is a reality. That such a condition ever does exist outside 

 the magination certainly awaits the proving. That laminitis may and 

 ofttimes does exist as a concurrent disease with numerous others is un- 



