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 UNIVERSITY OF CALIFORNIA Agricultural Experiment Station 
 
 College of Agriculture E. J. Wickson, Acting Director 
 
 BERKELEY, CALIFORNIA 
 
 CIRCULAR No. 19. 
 
 (April, 1906) 
 
 THE DISINFECTION OF STABLES, 
 
 By CLARENCE M. HARING, D.V.M. 
 
 By disinfection is meant the destruction of the germs of infectious 
 diseases. Negligence in properly disinfecting stalls and stables where 
 animals affected with contagious diseases have been, is frequently the 
 cause of a reappearance of the disease. 
 
 Many failures to eradicate tuberculosis from dairy herds by the 
 repeated application of the tuberculin test and the prompt removal 
 of all reacting animals, are due to the fact that the stables were not 
 disinfected. It is a universally accepted fact that herds of cattle, when 
 kept closely together in large stables, are the most liable to be badly 
 infected with tuberculosis. This is especially marked when the stables 
 have been in constant use for a number of years. Under such condi- 
 tions the dissemination of tuberculosis is very rapid, and continues 
 after all diseased animals have been removed and other cattle substi- 
 tuted. Since bovine tuberculosis is so widely disseminated, most dairies 
 in which the tuberculin test is not frequently applied become infected. 
 There can be no question but that frequent disinfection retards its 
 spread, and thorough disinfection of the stable at least once a year is a 
 precaution which should be taken by all. 
 
 The bacilli of glanders will remain alive under natural conditions in 
 stables for four months; hence a stable in which a glandered animal has 
 discharged virus will retain its infectiousness for a long time after 
 the animal has been removed, provided it has not been disinfected. 
 There are many other contagious diseases of animals which necessitate 
 thorough measures of disinfection in order to make eradication certain. 
 
 In view of the importance of disinfection in preventing the spread of 
 disease, the following directions are recommended for use in combating 
 infections : 
 
 1. Permit the Entrance of a Plentiful Amount of Light.— The bacteria 
 of tuberculosis and most other disease-producing germs are destroyed 
 by the direct rays of the sun within a short time. They are destroyed 
 
by less intense light more slowly, and will live for long periods in dark 
 places. There are numerous other advantages in having plenty of 
 light in a stable that are not necessary to mention here. 
 
 2. Clean the Stable Thoroughly.— Cleanliness is an important adjunct 
 to the work of disinfection. The cleaning of the stable includes: 
 (a) removal of manure; (b) removal of piles of fodder; (c) removal 
 of rotten woodwork and loose boards, especially of the floor; (d) sprink- 
 ling with a disinfectant, to lay the dust, and sweeping of the ceilings, 
 walls, and floor; (e) removal of dried accumulations about mangers, 
 floors, and drains. The practice of washing the floors and ceilings with 
 water before applying the disinfectant has, in most instances, the 
 disadvantage that the water carries the micro-organisms to be destroyed 
 into cracks where they will not be affected by the later application of 
 the disinfecting solution. 
 
 3. Apply Chemical Disinfectants.— After the stable has been treated 
 as recommended above, it is ready for the application of chemical dis- 
 infectants. These are substances which poison the germs. There are 
 many of them. Some are far more efficient than others. Among the 
 most active are carbolic acid and corrosive sublimate. 
 
 Carbolic acid, when pure, is crystalline. It readily assumes the liquid 
 state in the presence of a little water. As usually dispensed it con- 
 sists of 95 parts of pure acid and 5 parts of water. For use as a stable 
 disinfectant this should be mixed with water in the proportion of one 
 to twenty, or one pint of acid to two and one-half gallons of water. 
 The "crude carbolic acid, saturated solution" is much weaker than the 
 above, and should not be diluted with water. 
 
 Bichloride of wsrcury, or corrosive sublimate, is a most active germi- 
 cide, and has the advantage over carbolic acid for use in a dairy stable, 
 in being odorless. This substance is poisonous and must be used with 
 great care. Before it is applied it must be dissolved in water, in the 
 proportion of one part to one thousand. One ounce of corrosive sub- 
 limate dissolved in eight gallons of water makes a solution of the right 
 strength. In making the solution the corrosive sublimate should be 
 dissolved in one gallon of hot water and then mixed with enough cold 
 water to make eight gallons. It corrodes metal, hence the solution 
 should be kept in a wooden tub or earthenware crock. 
 
 There are many other efficient disinfectants, but the two above de- 
 scribed are cheap and obtainable at any drug-store. In the employment 
 of commercial disinfectants, it is necessary also to know the destructive 
 value of the solutions for the organisms to be destroyed. There are 
 many so-called disinfectants that, in the strength of the solutions 
 recommended, are inefficient. 
 
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 Disinfectants can not destroy germs with which they do not conn in 
 contact. The disinfectant should be applied in sufficient quantity to 
 thoroughly saturate the surfaces, including the adhering particles of 
 dirt. In the application of the disinfectant it is well to use a broom 
 and thoroughly scrub the floor and lower parts of the walls. The 
 solution can be applied to the ceilings and upper parts of the side walls 
 with a spray pump, and must be carried into every crevice and recess 
 into which dirt can enter. 
 
 After disinfecting, whitewash the stable. Although whitewash is not 
 an active disinfectant, in the usual meaning of the term, it is an 
 excellent purifier and should in all cases be used in stables after they 
 have been thoroughly cleansed and disinfected with other agents. If 
 chlorid of lime is added to whitewash in the proportion of one pound 
 to three gallons, the value of this application is greatly increased. It 
 is advisable to whitewash cow stables frequently, at least once in six 
 months, and better every three months. Hot whitewash for this purpose 
 is better than cold. 
 
 In preparing the above directions, abstracts have been freely made 
 from Pennsylvania Circular No. 2, by Dr. Leonard Pearson, and from 
 "The Pathology of Infectious Diseases of Animals," by Dr. V. A. Moore.