218 VETERINARY HYGIENE 



in the same time as a 1-100 solution of phenol, then 1000/100 is 

 10 ; 10 therefore is the " carbolic acid coefficient " of the dis- 

 infectant. This is known as the Rideal-Walker method of stand- 

 ardising disinfectants. 



This method of testing disinfectants is most suitable for 

 chemicals of the same class, such as those of coal-tar origin. 



DISINFECTION OF STABLES, COW BYRES, PIGGERIES, &c. 



With all disinfecting operations the modus operandi depends 

 upon the nature of the infective agent that has been at work. The 

 hygienist will naturally bring thought to bear upon the disease he 

 is combating, and will suit his tactics to the individual case. Here- 

 under are given the chief points to be considered with the more 

 common zymotic diseases; exceptional conditions must be met as 

 they arise. 



DISINFECTION FOR MANGE. It is of course useless to disinfect 

 a stall in which there still stands an infective animal, but it is like- 

 wise poor policy to keep an animal undergoing treatment in a stall 

 or box that is presumably harbouring numbers of the parasites. 

 The most satisfactory procedure to adopt is to remove the patient to 

 a clean stall after he has been thoroughly dressed and to give him 

 clean bedding on which to lie (the practice of keeping mange- 

 infected horses without bedding is not to be recommended), and then 

 to disinfect the vacated stall in the following manner. First 

 remove all the bedding and scrape as much as possible of the dung 

 and dirt from the floor. It is important to do this as soon as pos- 

 sible after the animal has left the stall as any parasites on the bed- 

 ding may attempt to migrate to the adjoining stall in which there 

 may be a clean animal. All this bedding and dirt should be placed 

 in a heap and burned without delay. Since the majority of the 

 parasites that have been left behind will be located on the floor, on 

 the stall partitions, and on the under surface of the manger and hay 

 rack it is to these that attention should be first given. Having 

 removed as much of the dirt as possible by scraping the floor, the 

 latter should be thoroughly soaked with a disinfectant, care being 

 taken that it penetrates into all the corners and angles. A 2 to 5 

 per cent, solution of Jeyes Fluid is suitable for the purpose. A 2 

 per cent, solution of Liq. Cresol. Sap. or of carbolic acid is said to 

 kill the mites in a few minutes, but it is advisable to use double this 

 strength. Though mange parasites soon die and their eggs dry up 

 in a dry atmosphere, it is probable that they will live for some weeks 

 in damp and dirty stables with uneven floors. If the disinfectant 



