Van der Schaaf A, Hopmans J L, Van Beek J
Tijdschr Diergeneeskd. 1976 Oct 1;101(19):1084-92.
During and shortly after the second world war, an infection bearing a resemblance to avian tuberculosis was observed in woodpigeons in Denmark and Great Britain. These birds had been found dead or been shot. The patogenic agent, however, could not be isolated by the usual methods. In the Netherlands, the disease was also detected in woodpigeons and occasionally in psittacine birds. The histological changes bore a resemblance to those observed in Johne's disease. Detailed bacteriological and experimental studies showed that there were two different infections. One agent was a mycobacterium of the species, which could not be grown on the usual culture media for M. tuberculosis, whereas it could on the media used in the culture of M. paratuberculosis, particularly Smith's medium. The bacterium also soon becomes rough on this culture medium. As a result, differentiation of serological types by Schaefer's method failed. The other type of mycobacterium (which indeed causes a similar form of intestinal disease) could be readily cultured and was identified as M. avium type 2. The former mycobacterium is still nameless in point of fact but is sometimes wrongly referred to as Mycobacterium columbae. This rod was not found to be pathogenic for the domesticated pigeon (Columba livia), not even when intestinal mucosa containing large numbers of bacteria and obtained from a diseases woodpigeon which had died recently, was inoculated orally in recently hatched specimens of the domesticated pigeon. To account for the appearance of tuberculosis in native woodpigeons, it is suggested that low plasma transferrin levels could result in marked susceptibility to infections such as tuberculosis and trichomoniasis.
