Kevin - there are no drugs that will eliminate a viral infection (the most
likely cause) or render it intransmissible.  All you can do to prevent
spread is quarantine, and be very careful yourself not to handle the
uninfected animals after the infected ones.
 
I generally do not recommend any specific drugs to treat the congestion
unless the animal is so stuffed up that he won't eat.
 
With kindest regards,
Bruce H. Williams, DVM, DACVP
 
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[Posted in FML issue 3358]