Impairment of metabolic capability in feral house mice by Klossiella muris invection.

Kidney infection by Klossiella muris in highland house mice from Peru was associated with lowered metabolic capability (57%) and endurance time (25%) at maximum metabolic rate. Administration of coccidiostatic preparations improved the metabolic capability from 7.8 to 10.5 cc 0-2 g hr and the endurance from 2.8 to longer than 10 min. Their colony-reared offspring, which were free from parasites, sustained maximum metabolic rates of 13.8 cc 0-2/g hr also for longer than 10 min. This rate was slightly higher than the values found in both healthy lowland controls: feral house mice from Arkansas and laboratory white mice [lab: HA(ICR)]. Although clinically inapparent under oridinary conditions, the effects of K muris infection were easily demonstrated at high metabolic loads stimulated by cold. Thus emphasizing the importance of such performance tests in assessing the status of experimental subjects.