First of all do get your father's fasting and post-prandial(i.e. FBS &PPS) sugar levels tested, as quickly as possible. If they are high, this can be the cause of the flare up in your father's wound and the infection itself could be aggravating the sugar level. Once the blood has been given for testing, get the toe treated by a surgeon. It would be a risk to the toe and your father's general health, if recovery were further delayed. Hope he gets better soon.