Issues with a dog’s respiratory system or heart can cause a dog to cough up clear fluid, or mucus, according to PetCareRx. Dogs may also cough up clear fluid when experiencing problems with the sinuses or esophagus.
When a dog hacks or coughs up mucus, the ribs and chest move, explains PetCareRx. Upper respiratory issues, such as kennel cough, can cause coughing and can lead to appetite loss. These infections can easily spread from animal to animal when dogs are in crowded areas, such as a dog park, a kennel, a shelter or a dog walk event. Treatment may include using a humidifier, providing a stress-free environment and giving appetizing meals. If the condition worsens or persists, pet owners can take the dog to the veterinarian for antibiotics.
Parasites may enter the heart, such as in the case of heartworm disease, and cause a dog to cough as a result, reports petMD. A dog can contract the larvae from the parasites that cause heartworm disease if bitten by an infected mosquito. The larvae travels to the dog’s heart and can grow almost 1 foot long when it reaches adulthood within six months. A mosquito can continue to spread these parasites if it bites an infected dog and carries the larvae to a healthy dog. Proper medication treats heartworm disease.