Ciprofloxacin is *not* contraindicated during breastfeeding.  It is an
odd choice to use for treatment of mastitis (there are other more
specific acting drugs, which happen to be cheaper, but that's modern
medicine for you).

There is a concern that ciprofloxacin causes articular damage in young
animals.  And it does, in young rats given it directly.  However, it
does *not* cause articular damage in humans, and definitely not in the
tiny doses which come through the milk.

Jack Newman, MD, FRCPC