Abstract
Hydronephrosis occurred in 6 of the 13 inbred mouse strains maintained in the same colony. Its incidence was high only in the BRVR strain, where about half of the cases could only be detected microscopically. There was no concomitant infection even in severely abnormal BRVR kidneys and the incidence of the condition was not influenced by dietary variation. The hydronephrosis found, less frequently, in 5 of the other strains was of a different type from that in BRVR mice.
