Q. Does one have to eat meat on the seuda of Purim?

A. Shulchan Aruch (O.H. 696: 7) rules that it is a mitzva to eat meat on Purim as it is included in the mitzva of simcha. He mentions that it is a mitzva of Divrei Kabalah equivalent to a Biblical mitzva. Rambam (H. Megila 2: 15) rules similarly. (See Baba Metzia 78b).
On question 1448 in regards to eating meat on Yom Tov we wrote; “Poskim disagree if on our days when we don’’t consume yet the meat of shlamim, if there still is a mitzva of eating meat and if it is Biblical. Biur Halocho (529: keitzad) maintains that although there is no obligation to eat meat, the mitzva remains. Some assert that the obligation also continues. (Nimukei Orach Chaim 529, Divrei Moishe 1: 11, Darkei Teshuva Y.D. 89: 19, et. al.).
Many Poskim maintain that the mitzva applies only to mammal’s meat and not fowls (See Piskei Teshuvos ibid. n.35). However, leniency is given to the one who for medical reasons may not eat or does not enjoy that or any kind of meat, as the mitzva is the pleasure and enjoyment. The minimum amount to comply with the mitzva is a kezais (about 28 g.)”
In regards to Purim Mogen Avrohom (696: 15) and other Poskim maintain that it is similar to Yom Tov.
Horav Shlomo Miller’s Shlit’a opinion is similar.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a