Dog Coughing Up Thick White Mucus. When you cough up thick, solid white mucus, it might be a signal that you have a bacterial infection in your airways. Top best answers to the question «why is my dog throwing up white phlegm» answered by eric grant on wed, mar 3, 2021 7:12 am.
Mucus that contains bubbles and is foamy is commonly referred to as frothy… 3 clear mucus. Mucus is a thick white liquid secreted by mucus membranes present inside the body. Dogs coughing up thick white mucus.