Are you thinking that he aspirated on the Metacam? If it was me, I don't think I would give him anymore & would talk to the vet right away. Since his eyes look sunken, I would put him in some bath water.
It's hard to say what is causing all of this. Can you post a picture of him? How is he doing now? You may need to take him to an emergency vet right away.
It's hard to say what is causing all of this. Can you post a picture of him? How is he doing now? You may need to take him to an emergency vet right away.