The Nine Days
It is a custom for all Jews not to eat meat and not to drink wine during the nine days from Rosh Hodesh (Av) until after the 9th of Av. It is forbidden even (to eat) something that was cooked with meat or contains (animal) fat.1 Even poultry is forbidden, but one who is made ill by dairy products, can eat poultry. For an ill person, everything is allowed, but in any case, if it is not difficult for him, he should stop from eating (meat) from the 7th of Av onwards. It is also the custom of some women after childbirth to avoid meat and wine from the 7th of Av onwards, because on that day the non-Jews entered the Temple. On a festive meal such as after a circumcision or redeeming a (first-born) son, or concluding a book of the Talmud, meat and wine are also allowed. Apart from one's parents, brothers and children, and apart from those who have a connection to the precept, one can invite another ten people who are friends, but only if those also at a different time would have come to him for a festive meal. All this2 is allowed even on the eve of the 9th of Av before midday but not after that. The meal that is customary to give on the night before a circumcision, is not considered as a festive meal and meat and wine are forbidden, and it should be made with dairy foods. The cup (of wine) for Havdalah at out Shabbat, if there is a child who can drink most of the cup, it is given to him, and if not the one making Havdalah can drink it himself.3 (KSA 122:8)
1) If the non-meat part was at least sixty times the meat (by volume), or if there is no taste of meat in the food, it is allowed. Similarly , non-meat (fish or parve) food cooked in a meat pot are allowed.
2) Serving meat and wine at a festive meal for a precept.
3) Havdalah is a commandment so it is possible to drink wine if necessary.