An outbreak of conjunctivitis, unaccompanied by involvement of the respiratory tract, is reported in a colony of white mice.
A special strain of pleuropneumonia-like organisms was regularly isolated from the eyes and nasal passages of affected mice but not from the lungs or middle ears.
Ocular carriage of these organisms in the absence of an inflammatory reaction occurred in at least 50 per cent of the adult mice.
Transmission to the young was presumably initiated by parental contact, the organisms being recoverable after the eyes were open, and was continued after weaning by direct contact between cage mates.
These organisms were repeatedly established on the conjunctiva of normal Swiss mice by direct contact with infected animals and subsequently maintained there for ten successive passages.
Multiplication of the pleuropneumonia-like organisms, which was largely limited to the eye and its appendages, was accompanied by a low rate of conjunctivitis.
The multiple conjunctival instillation of ocular washings from infected mice was the only additional method of implantation of the organisms which was successful.