METHODS FOR ERADICATING TUBERCULOSIS.

This subject has been discussed at some length by Dr. D. E. Salmon in Bulletin 38 of the Bureau of Animal Industry. Because of its important bearing on the improvement of the milk supply, the following extract from that publication is appended:

ERADICATION OF TUBERCULOSIS FROM THE FARM.

If there is any reason to suspect the existence of tuberculosis in a herd, an effort should be made at once to determine definitely whether it is present and which animals are affected by it.

The general condition of the animal should furnish some indication. If any of the animals are not doing well, are losing flesh, and fail to yield the amount of milk which is to be reasonably expected, a careful examination should be made of them to determine whether their temperature is normal, whether there are signs of enlargement of the external lymphatic glands, and whether abnormal sounds can be detected in the lungs. The examination of the carcasses of any animals which may have died or are slaughtered is a valuable indication as to the existence of the disease in the herd.

The most reliable means of determining this question is, however, the tuberculin test. While this may occasionally fail to reveal tuberculosis in an individual animal, it may be relied upon with certainty to reveal the existence of the disease in a herd. If this test indicates that some of the animals are tuberculous, measures should be at once adopted to eradicate the disease from the herd, or at least to prevent its further spread. In case there are only one or two animals affected, and these are not especially valuable, the best plan is to slaughter them at once and thoroughly disinfect the stable in which they have been kept. If a large proportion of a herd is affected, and the animals are not especially valuable, the best and cheapest plan would be to separate the reacting animals from the healthy ones, and to have the former slaughtered under inspection as soon as they can be put in proper condition. It is probable that the flesh of most of these animals would be found fit for food, and the loss, therefore, would not be very great. In case the herd has been long affected and many of the animals are in an advanced stage of the disease, they are unfit for milk production, and the sooner they are slaughtered the less will be the loss.

If the herd contains animals which are valuable for breeding purposes, the Bang system of management or some modification of it may be profitably adopted.

STATE AID FOR THE ERADICATION OF TUBERCULOSIS.

In the eradication of a disease so widely disseminated, and one which causes such serious losses to the animal industry of the country, there should be assistance offered by the State in order to relieve the burdens which fall upon the owners of live stock. A considerable number of States have shown a disposition to come to the assistance of farmers whose stock is affected, but the assistance has sometimes been coupled with conditions which made it unwelcome. In some States compulsory testing and the slaughter of reacting animals have been required, but this has not been a popular measure. It is essential that a plan should be devised which will meet with the approval of the stock owners and which will aid them without being too burdensome in its conditions. There are certain measures which have been adopted by individual States which have accomplished satisfactory results but which would be far more successful if adjoining States would adopt the same or similar regulations. Among the reasonable measures which a State may adopt for the repression of tuberculosis the following may be mentioned:

1. Cattle which are brought into a State for breeding or dairy purposes may be tested with tuberculin, and those which react may be refused admission to the State. In connection with this measure it should be provided that cattle which have been tested by the authorities of another State or of the Federal Government and found free from disease should be allowed admission without being retested. The testing of animals coming into a State is essential in any effort to control this disease and is one of the first measures which should be enforced in any effort to eradicate it.

2. There should be an inspection of all slaughtered animals coming from breeding or dairy herds within the State in order to discover in what herds the disease exists. Animals from the greater part of the milk-producing herds are being continually sold for slaughter as their usefulness in the dairy is over, and an examination of the carcasses of these cows would serve to locate the existence of the disease in many herds where its presence is unsuspected. Unfortunately, few of the animals killed in the small slaughterhouses are inspected, and in those cases where there is an inspection and tuberculosis is discovered it is seldom that the herds from which they came are traced and the owners informed of the discovery of this disease. In any effort to suppress tuberculosis it is almost essential that information of this kind should be obtained and an attempt made to persuade the owner to adopt proper measures for getting rid of the contagion.

3. Measures should be adopted for testing herds with tuberculin without expense to the owners. In the beginning of the work, at least, this should not be compulsory, but it should be made to the interest of the owner of a tuberculous herd to have it tested under the auspices of the State. Apparently, it would also be wise and a great aid to stockmen for the State to test herds with tuberculin and certify to the healthfulness of animals from all those herds where no reactions occur. At present it is a difficult matter in most States for the breeder or dairyman to purchase cattle for his herd with any assurance that they are healthy. He may have them tested, but there is always a possibility that they have been treated with tuberculin a short time before and that for this reason they have not reacted. The loss which has fallen upon the breeders of the country through the introduction of tuberculosis in their herds has been tremendous, and it appears that it would be only a proper aid and encouragement to agricultural interests to assist breeders in obtaining animals free from disease. Not only would this encourage farmers to enter into breeding operations and increase the value of the industry within the State, but the certification of breeding animals would help to build up a market in other States for breeding animals.

4. In order to encourage the owners of cattle to eradicate tuberculosis, States should allow a reasonable compensation for the animals which it is necessary to slaughter on account of being affected with this disease. It is certainly a matter of great importance to any State to have its herds free from tuberculosis and its animals and animal products above suspicion. With the recent demonstration of the communicability of animal tuberculosis to man, a demonstration which has been made by so many investigators and on such competent authority that the fact can no longer be questioned, there is a disposition on the part of sanitary authorities to scrutinize more carefully those animal products which are liable to be infected. It is, therefore, becoming every day more important for every State to repress tuberculosis within its borders and in that manner to maintain the reputation of its animal products. Where it is not deemed advisable to provide for slaughtering of all reacting animals with sufficient compensation from the State to make this measure satisfactory to the stockmen, the State may provide for the supervision of herds handled according to the Bang method or some modification of it. For the protection of its own citizens who consume dairy products, if not for the protection of its customers in other States, every State should make some arrangement which would lead to the removal of cows with tuberculous udders and those suffering from generalized tuberculosis from herds which supply milk, cream, and butter for human food. This much is essential for the public health, but it would be wise to go further and provide for the slaughter of all cows which show evidence on physical examination of being affected with tuberculosis.

5. In cases where cattle owners are to have their tuberculous animals slaughtered in an effort to free their herds from disease the State should further assist them by disinfecting or at least supervising the disinfection of the contaminated stables. It is a somewhat difficult matter for persons not acquainted with the practical operations of disinfection to carry out this measure successfully, even after they have been given explicit instructions. It is impossible to impress sufficiently the importance of thoroughness upon persons who are lacking in experience in this line of work. As a consequence the majority of the premises disinfected by stockmen without the assistance of experts are imperfectly disinfected, and the disease breaks out again among the animals which are subsequently introduced. This is discouraging to the owner and serves to fix the impression that it is impossible to eradicate tuberculosis. This impression is already widespread, but it is essentially wrong, though it can only be removed by object lessons in the eradication of the disease under State supervision. There is no reason why tuberculosis should not be eradicated as pleuro-pneumonia was eradicated. The contagion is more widespread and the expense would be greater, but there are no inherent difficulties to prevent the success of such an undertaking.

6. When a herd has been freed from tuberculosis by the slaughter of all reacting animals, and the premises have been properly disinfected, the State should give further aid to the stock owner by testing without expense the animals which he desires to purchase for renewing his herd. This measure is essential to the success of any plan for lessening the prevalence of this disease or eradicating it. The expense of testing such animals is almost too great to be borne by the individual, and, moreover, private tests are often unsatisfactory and unreliable.