A dog spitting up mucus like phlegm may be caused by colds, improper diet, indigestion, internal parasites, viral infections, gastrointestinal diseases, etc. Among them, respiratory tract infections caused by colds are the most likely, and are generally accompanied by symptoms such as sneezing, runny nose, and coughing, and dogs who drink water all the time are actually diluting sputum. The owner can also give it some cough syrup.

If the dog has other symptoms, it is recommended to take it to the veterinary hospital for an examination to confirm the cause in time Treatment, usually pay attention to the dog's diet and keep warm, deworm the dog regularly, vaccinate the dog, eat some fresh and light fruits and vegetables properly in the diet, and also give it some vitamin B. It can help it recover faster.