My dogs wind smells horrid? no change to diet..?

My 15 month old bull mastiff has had the worst smelling wind for the last 2 weeks. He has been on antibiotics recently for cysts and an allergic reaction causins allover his skin, we had been advised to cut back on few things that we feed him that may be causing the reaction. We have done this but not added anything to his usual diet of dry kibble with small amounts of meat, eggs, carrot and sometimes potato. He has never been a windy dog apart from when he was a few months old and the food he was fed was had a too high meat content ontop of the meat we gave him. Any ideas of how to stop this or help the foul smell ( very pungent ) and i also think it has a marajuana like hint to it but maybe thats just my hormones due to being pregnant. Thanks alot :)