Slander is actionable per se in the following classes of cases:

(1) Where the charge, which is the basis of the action, imputes to the plaintiff the commission of an indictable offense involving moral turpitude;

(2) Where it imputes that the plaintiff has a contagious or infectious disease of a disgraceful kind;

(3) Where the charge is one tending to injure the plaintiff in his office, business or occupation; and,

(4) Where the charge is one tending to disinherit the plaintiff.

In all other cases of slander special damage to the plaintiff must be proved before there can be a recovery.