Are only Kohanim forbidden to eat Neveilah and Tereifah?
Rashi citing Menachos 45a: Kohanim are permitted to eat Melikas ha'Of, which is Neveilah (the Kohen cuts its Simanim with his thumbnail; this is not Shechitah). Therefore, they are warned not to eat other Neveilos and Tereifos 1 .
Radak: Also the Torah warns them in particular, "Neveilah u'Tereifah Lo Yochal Letam'ah Vah" (Vayikra 22:8). They are warned more due to Tum'ah, for they are always 2 in the Mikdash. [Even though the special warning is due to Tum'ah], it says Lo Yochelu, and not Lo Yiga'u, for there is a Neveilah that is Metamei only when swallowing it, but not via touching it i.e. Nivlas Ohf Tahor.
Malbim: In the future they may not eat even something that looks like Neveilah or Tereifah, i.e. a dangerously sick animal. Chazal expounded "Neveilah u'Tereifah Lo Achalti" (4:14) - an animal that was hurriedly slaughtered before it died (Chulin 37b).
Malbim: I.e. they may not eat Melikah of Chulin. (The verse includes Behemah. Is it possible to cut an animal's Simanim with one's fingernail? - PF) The Torah already warned Kohanim specifically ? what does Yechezkel add? Refer to 44:31:1:3.
I.e. they are in the Mikdash more regularly than Yisrael. Each Mishmar served in the Mikdash two weeks per year, and during the festivals. (PF)