Answer by Carolynn Harvey, DVM:
Even when rabbits make an apparently complete recovery from “snuffles,” they may still harbor the causative bacteria deep in their nasal passages or sinuses. The chance of Blackberry passing the infection on to your other rabbit will be much less than when she was sneezing and having nasal discharge, but there is still some risk. The overall health of the other rabbit, its stress level, and its previous exposure will determine the outcome. If you want to know more, nasal culture of the sick rabbit and Pasteurella titers on both could help you further assess the risk. In general, I feel the benefits of companionship outweigh the risk in this situation.