Diseased Bird: Sick/injured Mourning Dove

On 11/28/15, among the 35 (that day; some days 55) usual Mourning Doves eating from my seed and cracked corn ground spread, this dove was seen with a red left eye along with pulled and matted feathers about the neck and left side of face. I couldn’t decide if it had been attacked or was sick. The photos are poor due to dim light and window glass but the eye looked redder (blood red) than in the photo attached . Despite careful observations throughout following week I did not see the bird again, however I did find a dove kill 2 days later (the only one so far this feederwatch season) in the same area. Can’t help but wonder if it was this more vulnerable bird. I had a Sharp-shinned hawk here then plus there are dusk-hunting owls in the woods surrounding my place. I continue to watch the flocks here closely but have seen no other sick/injured doves nor red-eyed birds of any species.