He’s not sick, he’s sad. Missing Nina.
Also likely scared out of his little mind; his mistress is missing, the apartment is sealed off (no walks and going outside), these weird people show up and invade his home space, he’s forced to deal being chased/caught/leashed and then shoved in a cage, then transported into the outside, but instead of a nice calm lawn with friendly people, he’s being carried into a lawn loaded with police and cars and ambulances and he’s being handled by people in space suits and he can’t even see the face or make some kind of psychosocial or friendly connection.
My eyes would be wide open and glazed as well.