My dog might have heartworm. What symptoms should I look for?
Hi. I sure hope Mason doesn't have heartworm disease. In the early stages of heartworm infection, dogs show few symptoms or no symptoms at all. The longer the infection persists, the more likely symptoms will develop. More active dogs, dogs heavily infected with heartworms, or those with other health problems often show pronounced clinical signs.
Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue, appetite changes, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen. Dogs with large numbers of heartworms can develop a sudden blockages of blood flow within the heart leading to a life-threatening form of cardiovascular failure showing labored breathing, pale gums, and dark bloody or coffee grain like material in urine.
If you are worried about Mason possibly having Heartworm disease, please schedule an appointment and testing with your veterinarian.
Updated on September 23rd, 2025