Respiratory disease in a colony of rats: I. The natural disease

Abstract

SUMMARYAn epidemic of acute respiratory disease in a colony of CFE rats is described, the main laboratory findings are recorded and its aetiology discussed.The epidemic showed that severe respiratory disease varying from peracute to chronic was associated with infection of the lungs withi a mycoplasma but that mycoplasmas could be present in rats, even in the lungs, without signs of disease, thus suggesting that one or more other factors were involved. It is also evident that there are strain differences in the susceptibility of rats to this disease.

Respiratory disease in a colony of rats. II. Isolation ofMycoplasma pulmonisfrom the natural disease, and the experimental disease induced with a cloned culture of this organism

“…The respiratory disease in the experimental animals of groups A and B was less acute than that observed during the natural outbreak at Alconbury described by Lane-Petter et al (1970), in that it took a long time to become severe and cause deaths. This might indicate that in the Alconbury outbreak an agent in addition to M. pulmonis was involved, and that this was not present in the material used to inoculate the experimental rats.…”

“…That M. pulmonis was estab-401 P. WHITTLESTONE AND OTHERS lished in the Alconbury colony (Lane-Petter et al 1970) was confirmed by the regular isolation of mycoplasmas from affected rats -those isolates checked serologically all proved to be M. pulmonis -and by the detection of antibody in several other rats (R. J. Olds and R. M. Lemcke, unpublished observations).…”

“…Seven rats which were affected with respiratory disease in a natural outbreak at Alconbury (Lane-Petter et al 1970) were removed to an isolation cubicle at the School of Veterinary Medicine, Cambridge, where they were held for a few days to allow clearance of the previously administered oxytetracycline before they were killed. The lungs of two of the rats, 3102 and 3103, were quantitatively cultured for mycoplasmas and were examined bacteriologically.…”

“…Before introducing rats into a new cubicle, all the equipment was either steamed or autoclaved, and the whole cubicle with its equipment then fumigated with formalin. Food was autoclaved and the drinking water acidified (Lane-Petter et al 1970). Rats were kept in plastic boxes with wire-mesh tops and were provided with sawdust bedding and wood shavings.…”

“…The present work was therefore undertaken to investigate whether a recent isolate of M. pulmonis from a case of pneumonia in a naturally occurring outbreak of severe respiratory disease in rats (Lane-Petter, Olds, Hacking & Lane-Petter, 1970) would induce a similar respiratory disease syndrome experimentally, and to study the serological response to experimentally-induced infection.…”