Q. I have a Canary bird couple of days ago I noticed that open&close his mouth constantly and has difficulty breathing and is beating his beak
A. He may have a respiratory infection or mites. Have him seen by an experienced avian vet for a physical exam and treatment as indicated. Clean and sanitize the cage, bowls, toys, etc. Keep it out of direct sunlight and away from drafts or breezes. Make sure he continues to eat, drink and eliminate normally. If he is having difficulty perching, see a vet sooner rather than later.