When a dog shows symptoms of retching and vomiting white mucus, it may be caused by gastrointestinal disease, improper diet, food poisoning, viral infection and other diseases. If found, seek medical attention immediately. When feeding dogs, do not feed raw or cold food that is difficult to digest, as it can easily irritate the gastrointestinal tract and even lead to acute gastroenteritis. Do not place toxic substances in places where dogs can easily touch them. Pay attention to environmental disinfection to avoid virus infection.