3. [The following rule applies to] food which is forbidden to be eaten by
a Jew, but from which a Jew is allowed to derive benefit: if it is fit to
be given to a Gentile in its present state, for example, cooked meat, and
one owns the meat, and thus has the power to give it to a Gentile, then the
meat is allowed to be handled on Shabbos (that is, its not muktzeh) (1).
If, however, it is not fit to be given to a Gentile in its present state,
for example, uncooked meat (and it is not considered dog food, because it
is fit for consumption by a Gentile), handling it is forbidden. It is also
forbidden to be handled if one does not have the power to give it to a
Gentile, because one is not the owner.
(1) However, food from which a Jew is not allowed to derive any benefit
whatsoever, such as chametz on Pesach or meat cooked in milk (that is, one
is not even allowed to give it away as a gift), is considered muktzeh and
may not be handled on Shabbos (See Mishna Berura 444:6).