Predisposing Causes of Roaring. 41 



2. Heredity. 



The question of heredity of predisposition is a very im- 

 portant one for consideration, as, if it really exists, unlike 

 climate, it can be controlled. 



Of its existence I think there can scarely remain a doubt. 

 We do not know when Roaring first began to be observed 

 in England, but it would not appear to have been much 

 noticed until within the last century or two. Was the ten- 

 dency to it imported into this country by foreign horses of 

 large size ? Godine, jun., long ago asserted that the defect 

 was introduced into Normandy, in 1764, by Danish stallions 

 which were Roarers.^ May we not have got it among our 

 horses from a similar source, and about the same time ? 



It has been stated that the famous race-horse, EcHpse, 

 was affected in his breathing. Youatt says : " Eclipse was 

 a ' high-blower.' He drew his breath hard and with appa- 

 rent difficulty. The upper air-passages, perhaps those of 

 the head, did not correspond with his unusually capacious 

 chest ; yet he never was beaten. It is said that he never 

 met with an antagonist fairly to put him to the top of his 

 speed, and that the actual effect of this disproportion in the 

 two extremities of the respiratory apparatus was not 

 thoroughly tested."- Whether this " high-blowing " was the 

 defect we are now studying, there is no other evidence to 

 show. Certain it is, however, that Roaring began to receive 

 attention about this time, and towards the beginning of this 

 century suspicions of an hereditary tendency to it were 

 being entertained. Soon strong proofs of the reality of such 

 a tendency were accumulated and published, and some of 

 them were sufficiently convincing. 



K. Gilnther, in Germany, and Stockfleth, in Denmark, 

 maintained that Roaring is hereditary, and gave evidence in 

 support of their opinion. 



^ " Traite d'Hygiene." ^ " The Veterinarian," 1833. 



