Investigations concerning bovine tuberculosis : with special reference to diagnosis and prevention / conducted under the direction of D.E. Salmon.

Date:: 1894

Credit: Investigations concerning bovine tuberculosis : with special reference to diagnosis and prevention / conducted under the direction of D.E. Salmon. Source: Wellcome Collection.

31/196 page 27

$organ is not likely to be primarily affected, and tuberculosis of the central nervous system is quite rare, tlie inferences and conclusions that may be drawn \¥ill not be affected by this omission. Before discussing the lesions more in detail I deem it desirable to call the attention of the reader to pages 139 and 140, which give, in tabulated form, the distribution of the disease in the body as shown by the organs and structures involved. The table needs no explana- tion beyond the statement that the entire distribution of the disease is given, nothing being omitted which came to light at the autopsy. The diagnosis, where any doubt existed, was made by the microscoi)ic examination of sections. In several cases guinea-pigs were inoculated to test the vitality of the virus in cheesy material. The first thing that will strike the reader as remarkable in looking over these tables is the high iiercentage of infection in a herd in which not more than 5 or G showed evidence of disease. The concealed char- acter of the affection was not always limited to the very mild infections, but in some cases considerable lung disease remained unobserved dur- ing life. Of the 60 animals killed only 7, or about 12 j)er cent, were free from all traces of tuberculosis. In the remaining 53 the disease varied very much in intensity, ranging from the smallest, probably quiescent focus in one of the thoracic glands, to advanced tuberculosis. In order to present these cases more intelligibly 1 shall discuss, in the order named, (1) tuberculosis of the glands of the head and neck, (2) of the thoracic organs, and (3) of the abdominal organs. In the head the disease was restricted mainly to the retro-pharyn- geal glands [Glandulce tracheales seu cervicales superiores [profundce] ). These glands are easily reached after removing the tongue, and it is con- venient to remove them together with the tonsils for examination. From the table it will be seen that these glands were diseased in 9 cases (17 per cent). In 5 they contained the only foci discoverable. In the remaining 4 disease of other structures also was present. The submaxillary lymph glands were free in all cases. In one case (No. 315) the tonsils and one parotid lymph gland were tuberculous. The retro-pharyngeal glands, situated dorsad and to one side of the pharynx and larynx, receive the afferent lymphatic vessels from the parotid and the submaxillary lymph glands * and hence the territory drained by the lymphatic vessels, which finally enter these glands, includes the mucous membrane of the mouth and nose, in other words, of the entire portion of the respiratory and digestive tract lodged in the head and upper portion of the neck. In the five cases in which tuberculosis of the retro pharyngeal glands was the only discoverable focus (Nos. 309, 315, 329, 344, and 352), the tubercle bacillus must have been carried from the mucous membrane of the mouth, nose, tonsil, or pharynx into the gland. We do not know, therefore, whether the virus was deposited from respired air or taken - - - .J * EncyldopUdie der gesammten Thierheilkunde, vi, 216.$