Pork is forbidden for Muslims and Jews. Why is it that pork is not forbidden for Catholics?
Because God revealed to the apostles that the dietary laws of the Old Covenant were no longer binding upon Christians (Acts 10:9-16). Paul stated:
Therefore let no one pass judgment on you in questions of food and drink or with regard to a festival or a new moon or a sabbath. These are only a shadow of what is to come; but the substance belongs to Christ (Col. 2:16-17).