Suppression of infective diseases implies the adoption of measures more or less stringent, according to the character of the disease. First in order stands the so-called stamping-out system, which includes slaughter of diseased and infected animals, or in place thereof perfect isolation, which would be equally effective if it were not that it is almost impossible to ensure it. In cases of disease which terminate fatally in the majority of instances, slaughter does not imply any great sacrifice, but in other infective maladies which ordinarily end in recovery isolation would naturally be substituted, and it may be here useful to suggest some of the precautions which the effectual adoption of that system involves. The first requisite is a box which is entirely disconnected from other stalls or boxes, by which, of course, is meant that the walls and boundaries - no matter of what material they may be composed - although as a matter of course brick walls properly cemented so as to obtain a smooth surface are preferable to any other material - should extend from the floor to the ceiling; the entrance door should be also solid, light being admitted by a properly arranged window, and ventilation provided for as far as possible by openings in the ceiling. Next, all the appliances which are necessary in the feeding and general management of the animal should be kept in the box; and further, the man attending on the sick beast should have a waterproof covering which he can put on when entering the box, taking it off and leaving it in some convenient place as he comes out. It may seem hardly necessary to suggest that washing; his hands in a disinfecting fluid and cleansing and disinfect-ing his boots are simple matters of precaution which commend themselves to common sense, and cannot possibly be omitted without definite and incalculable risk being incurred of spreading the disease.
During the time that a sick animal is kept in the isolation-box the free use of disinfectants is to be recommended. In the present day there are disinfectants which possess no odour, which can be used without giving offence to the most delicate nostrils, so that the common objection to their employment is easily disposed of. As soon as an animal has recovered, and is considered to be sufficiently well to leave the box, thorough cleansing and disinfection will necessarily follow. The procedure will not materially differ whether the animal has been slaughtered in consequence of having been affected with glanders or has recovered from an attack of influenza or strangles; in the latter case, however, it would not be unreasonable to disinfect the animal itself, immediately it comes outside the box, by sponging it over with a solution of Chinosol, and thoroughly washing its feet.
In regard to the box from which a diseased animal has been taken, the litter which has been used during the time of its illness, instead of being carted away for manure, should be taken to a convenient place to be burnt, or, this being impossible, it should be thoroughly mixed with quicklime; the floor, after being sprinkled with lime should be thoroughly swept, and the walls and all parts of the box should be thoroughly washed with hot water in which a liberal quantity of washing-soda has been dissolved. This preliminary washing is perhaps the most important part of the whole process, and no amount of disinfection can compensate for its neglect. In a properly constructed isolation-box the rack and manger and water-trough would all be made of iron, and therefore could easily be cleansed and disinfected; but if the animal has been kept in a place where wooden racks and mangers are used, the most effective measure would be to have them pulled down and burnt, especially if the wood-work is in any way damaged, and the same course would be wisely adopted with regard to brushes, buckets, sponges, rubbers, and any other apparatus which has been used about the diseased animal.
After the sweeping and washing have been thoroughly done, all parts to which the cleansing process has been applied should undergo disinfection, and there is no doubt whatever that fumigation with chlorine gas, or sulphurous acid from burning sulphur, is the most effective means which can be adopted; but to be perfectly effectual the place must be so arranged that it can be completely closed while the gas is being disengaged. The ordinary sulphur candle supplies a convenient and satisfactory means of filling a place with sulphurous acid gas. Chlorine may be most readily set free by filling some common dinner-plates with a mixture of common salt and peroxide of manganese, and then pouring over the mixture ordinary commercial hydrochloric acid. As soon as the gas commences to escape, either from the sulphur candle or the mixture of salt and manganese, the door should be closed and the place left for twenty-four hours. The disinfection may be completed by applying to the floor and walls and all parts of the box a solution of any of the numerous disinfectants which are in use. Carbolic acid is most commonly employed, and in a mixture with twenty or thirty parts of water is very effectual for the purpose.
A place which has been properly disinfected should be fit for use for another animal as soon as the walls are dry, and this statement will answer the question which is commonly put as to the length of time which ought to be allowed before infected premises are again used for keeping animals. Clearly it must be the case that if the infected matter has been thoroughly destroyed or removed, time is a matter of no consequence, and if the process has been imperfectly done, and active infective matter is still left, it is impossible in many cases to say how long it may remain active. In fact, it would be necessary to make a different calculation in regard to each infective disease. Most probably the duration of the life of many kinds of virus discharged from diseased animals is brief, otherwise infective disorders would be more rife than they are. There are, however, always ready for quotation, stories of the wonderful vitality of infective matter, and it is at least satisfactory to keep an animal out of a place where microbes may possibly lurk until the danger may reasonably be regarded as a thing of the past.
A more serious difficulty is the want of proper appliances, in most private premises, for isolation and disinfection, and, further, the failure on the part of the owner and the attendants to realize the necessity of minute attention being paid to each detail of the cleaning and disinfecting process, whereas the smallest blunder may render the whole procedure useless.
It will probably be a subject of enquiry what is the best course to be pursued in instances when, from the construction of premises and other circumstances, it would be absolutely impossible to carry into effect in their entirety the means which have been recommended, and the answer can only be in effect what is provided in orders relating to disinfecting and cleaning processes, viz. that where the premises cannot be disinfected, as in the case of a field, for example, in the manner directed, it shall suffice that they be disinfected as far as practicable.