
chronic respiratory disease in mice and rats
chronic respiratory disease (crd) in both mice and rats embraces two
separate entities, namely: infectious catarrh caused by mycoplasmas
(pleuropneumonia-like organisms) and enzootic bronchiectasis by a virus.
the two syndromes are discussed in regard to their etiology, pathologic
manifestations, and transmission.  particular attention is paid to the relation
of mycoplasmas to infectious catarrh.  the morphologic and cultural
characteristics of the catarrhal types of these organisms are considered
from the standpoint of differential diagnosis.  the importance of crd in the
maintenance of breeding colonies and in the use of animals for experimental
purposes is stressed.  methods for the establishment of specific pathogen-free
colonies, as a means of control, are briefly outlined together with
observations on a cesarean-derived line of swiss mice.
