INCIDENCE OF T.B.

Timaru Herald, Volume CXLV, Issue 21087, 13 July 1938, Page 3

INCIDENCE OF T.B.

SEVERAL VARIETIES POSSIBILITY OF INFECTION Tuberculosis is a slow, chronic, wasting disease common in all animals, even fishes and cold-blooded reptiles. It runs, therefore, through a very wide range of types, and the organism responsible for the disease becomes modified in different species. From the farmer's point of view there are three important types of the germ—the human, affecting human beings, the bovine, found typically in cattle, but which can ; Iso infect horses and pigs, and the avian, or bird type, which is found in poultry, water fowl and wild birds. All of these three germs are quite distinct from each other both in their shape and their growth when grown artificially outside the body on broths and soups containing the eggs. The disease to which they give rise, is, however, the same in all animals—usually slow in commencement, and then flaring into an acute form which kills the sufferer in a few short weeks. Rapid Growth The germ affecting poultry cannot infect man, so far as is known. But it is a rapid growing germ which not infrequently is the cause of tuberculosis in farm animals, particularly cattle and pigs. Birds of one to two years are particularly affected, and being small and covered with feathers, their gradual wasting is not noticed. There may be no outward symptoms and the condition is only detected when tha bird is picked up, when the loss in weight will be apparent. The lungs are less commonly affected, and the "dots” or tubercles do not generally become hard in the centre as in other animals. They may be mistaken for the tumours formed by a disease of the blood-forming organs called Leucosis, but the spleen is seldom affected in this disease, whereas in tuberculosis it is almost always diseased. This forms a guide between the two complaints. Danger to Stock It is not possible to infect poultry which the germs of human or bovine tuberculosis, but the poultry germ can infect all farm animals. In calvos it may cause a positive reaction to the tuberculin test, and in milking cattle may sometimes be found causing tuberculosis of the udder. Pigs are especially affected, particularly in the glands about the throat region. So common is infection in pigs in Britain that in setting up a T.B. free herd, all the pigs are tested for example in opposing ears, i with both bovine and avian tuberculosis, and quite a large number re- ' act to the avian urebculosis. Mice and rats and wild birds, such as sparrows, can also be infected by poultry suffering from the disease. These creatures may then carry the infection to other parts of the farm. The avian germ, like that of the bovine and human, is surrounded by a wax capsule which makes it very hard to destroy. Carcases of birds which have died or been killed with the disease and buried have been found to be infective after nine months. Thus, such carcases should a'ways be burnt. Avian Tuberculosis Avian tuberculosis may be a severe menace, not only to the poultry flocks, but to the other farm animals. Poultry should nev?r be allowed to run with the uther animals, particularly cattle and pigs. The common practice of running pigs and poultry in an orchard, for example, is fraught with grave danger. Poultry tuberculosis, as in all other animals, including man, flourishes particularly when large numbers are crowded together in a small space; but even when the birds are kept on free range, as on a general farm, they should be | kept well away from the other stock.