Mycoplasmosis in rats

Chronic respiratory disease (CRD) is a frequently diagnosed ailment in pet rats. It is characterized by rattling moist respiratory sounds, labored breathing, sneezing, and coughing. A necropsy of such animals often yields the rodent pathogen Mycoplasma pulmonis in their lungs, independent of the actual cause of death. Many veterinarians have assumed that most rats are carriers of this organism without necessarily showing clinical symptoms. To confirm this hypothesis, nasal washes from 113 rats from all over Germany were tested for the presence of M. pulmonis. Mycoplasma could be isolated from 100 samples; 99 isolates could be differentiated as M. pulmonis. Mycoplasma could not be isolated from 13 samples, These results show that a high incidence of M. pulmonis could be detected in the upper respiratory tract of (mainly) healthy rats.