Otitis may cause itching or pain.
If the dog or cat is itchy, it manifests it by shaking its head or scratching the skin near the ear pinnae causing excoriations.
If the dog has ear pain it may keep its head tilted to one side and may overreact aggressively when stroking its head near the ear.
If otitis has set in suddenly and in only one ear, it is important to have the dog checked by the veterinarian as soon as possible to see if a foreign body (e.g., grass awn) has entered in the ear canal.