Toxoplasmosis is a disease which is sometimes spread through animal
feces, especially cats'.  It's nothing to worry about, unless you're
pregnant, have a very young child, or have a weakened immune system --
it's very dangerous to a human fetus in the first stages of
development, it may be dangerous to infants and toddlers, and it's a
concern for those who are HIV+.  Ask your doctor if you think you
might be susceptible.

Dr. Bruce Williams, DVM, says:

     Toxoplasmosis has been reported twice in ferrets.  Ferrets will
     not shed the toxoplasma organism to the extent that cats do, but
     if they are exposed to cat feces, they may contract the disease
     and shed very low amounts of oocysts.

     Here's the bottom line.  Because of the devastating effects that
     Toxoplasma can have on a developing human fetus in the first
     trimester - you don't want to take ANY chance at all on exposing
     [a pregnant woman] to Toxo.  So [someone in the household who
     isn't pregnant] inherits all litterbox duties for the next
     nine months.  Actually, she probably stands a higher chance of
     getting Toxo from poorly cooked beef.  The doctor says - if she's
     a carnivore - better get used to well-done steaks....