Why Is My Dog Throwing up Mucus?

There are two reasons a dog may throw up mucus: it may be regurgitating food that is just covered in mucus, or it may be hacking up mucus due to coughing. Generally, if the dog's chest and ribs move visibly while it expels the mucus, it's related to coughing; if it just comes out without effort, it is likely a regurgitation of food.