Several methods of facilitating the rapid recovery of tubercle bacilli from inoculated guinea-pigs have been suggested. Intraperitoneal inoculation requires at least six weeks for the satisfactory development of lesions, subcutaneous inoculation at least four weeks. Exposure to roentgen rays previous to inoculation has been suggested to increase the susceptibility and make possible a recovery of the tubercle bacillus in two weeks. With intrahepatic inoculation, a search for tuberculous abscess is made after two weeks. All these methods require killing the animal, the test is interrupted, and further observation is impossible, particularly in apparently negative or doubtful cases. Besides, it may be necessary in some of these tests to make tissue examinations in order to arrive at a diagnosis.
With intracutaneous inoculation, a result can be obtained in less than two weeks; the development and location of the lesion are always under observation, and the animal may be kept alive for
Schulz RL. GUINEA-PIG INOCULATION FOR TUBERCLE TEST. JAMA. 1923;81(23):1951-1952. doi:10.1001/jama.1923.26510230001012