Buying and selling all kinds of in toxicators is unlawful and invalid. Buying and selling haram meat animals or animals with halal meat which have not been Islamically slaughtered is permissible for those who consider their meat to be halal. There is also no problem in buying and selling these animals for decoration. Selling haram meat fish to Muslims is also permissible on the condition that the fish has extensive use including feeding birds etc. Otherwise it would be impermissible. Based on obligatory precaution, selling wine and pig to non-Muslims is not permissible. But there is no problem if they are not sold for human consumption rather for other rational use for example when one sells pork as dog food or wine for the production of industrial alcohol. There is no problem in using the food and medical products of the ahl al-kitāb in their hospitals, but one should abstain from eating the meat served in such hospitals.