Hi All,
Me again!

Regarding this mastitis that won't clear...

Has the milk been cultured to find out if there is a specific type of
bacteria involved?  Maybe this would help to find the appropriate antibiotic.
Also, if the milk tastes alty/sour, this sounds to me like an infection of
some sort.  Could she have a deep abcess?  This might explain the deep pain,
redness that won't clear, etc.

Just a few thoughts, hope they help!
Jay