250 



VETERINARY HYGIENE 



That the prevalence of anthrax is not in proportion to the 

 number of cattle is strikingly shown in the following figures taken 

 from the annual report, Chief Veterinary Officer, Board of Agricul- 

 ture for 19H,* Devon with 303,214 head of cattle had 10 attacked ; 

 Aberdeen with 179,078 head had 93 attacked. This is at the rate of 

 3-3 deaths per 100,000 head for Devon and 51-9 deaths per 100,000 

 head for Aberdeen. Outbreaks among horses and pigs may be 

 regarded as subsidiary to cattle outbreaks. 



With regard to seasonal incidence, Stockman has laid emphasis 

 on the fact that there is a marked and constant drop in the number 

 of outbreaks during the third quarter of the year, that is when the 

 animals are at grass. This depends upon the now well recognised 

 fact that in a very large proportion of outbreaks in cattle, infection 

 has been introduced through the medium of artificial feeding stuffs 

 which have been imported from countries in which anthrax is pre- 

 valent. The probability is that cake, meal, &c., becomes contam- 

 inated during shipment from dried hides which are often stowed on 

 top. The detection of anthrax spores in food which has presum- 

 ably been the source of infection has not, as a rule, been attended 

 with success, though M'Fadyean and others have been successful 

 in some instances. One such case occurred in London in 1895, in 

 which 14 horses died after eating a certain sample of oats, and 

 M'Fadyean was successful in finding anthrax bacilli in the con- 

 signment by means of inoculation. Anthrax is thus usually con- 

 veyed to animals by ingestion. Another source of infection is 

 the use of bone manure, but this material is more likely to be 

 rendered harmless owing to the chemical processes through which 

 such manure passes. That infection from this source is not very 



* Cd., 7852, 1915. 



