A video posted to YouTube with a link here might help. They sometimes will get stridor, a high pitched sound made on breathing in and out if there is something in the airway, such as mucus, swelling, a piece of food, or a foreign body. If they cough it out, it may not last long. If they have a respiratory disease, it may last longer. They can also wheeze or have rales (rattles.) A respiratory infection can be from a virus, bacteria, or a fungus. Do you see any watery eyes, eye bubbles, nasal drainage, sneezing, or labored breathing?