What Are the Symptoms of a Dog Having Heartworm?

What Are the Symptoms of a Dog Having Heartworm?

What Are the Symptoms of a Dog Having Heartworm?

What Are the Symptoms of a Dog Having Heartworm?


Heartworm disease is a potentially fatal but preventable threat that affects dogs. Parasitic worms transmitted through mosquitoes cause this invisible disease. Heartworm larvae develop under the animal’s skin before migrating through the blood vessels to the heart and lungs. The microscopic larvae develop rapidly, reaching between five and 12 inches in maturity.

It is vital to identify the symptoms of a dog having heartworm since it can take months before your pet exhibits signs of heartworm infection. Early detection will help ensure effective treatment. The stage of the worm’s lifecycle will determine the symptoms that your dog displays. So, here are some symptoms to look out for.


Persistent Unproductive Cough

One of the early warning signs that your dog may have heartworms is a persistent and unproductive cough. The dry cough is different from a regular cough that is sporadic and strong.

The heartworm cough usually happens after exercising. It can even be induced by mild exercise as the parasites move to the lungs and reproduce. It causes blockage and discomfort. Sometimes, the coughing fits can lead to fainting.


Lethargy or Inactivity

If your dog is looking more tired than usual or has lost interest in walks, it could be due to heartworms. Lethargy or inactivity is a symptom of heartworm infection, so it is vital to pay attention to your pet’s energy levels.

As the infection worsens, any physical activity becomes too strenuous, and your pet will not want to go outside. It becomes difficult for the dog to remain active even during low-energy activities.


Loss of Appetite/Weight Loss

As the heartworm infection spreads, finding the energy for the simplest activities, including eating, is hard. The dog will avoid routine actions like enjoying a snack, and it results in rapid weight loss.

Weight loss can be a symptom of heartworms or other illnesses. If you notice inactivity and lack of appetite, you need to take your pet to the vet immediately.


Difficulty Breathing

As heartworms mature in the dog’s body, they affect the surrounding veins and lungs. It causes blockage and symptoms that include rapid and shallow breathing. Consistent coughing and breathing difficulties can mimic an asthma attack. Fluid buildup in the lung blood vessels makes it difficult for the blood to be oxygenated. It results in difficulty breathing.


Distended Chest/Bulging Ribs

Fully grown heartworms lead to visible symptoms. A bulging, distended, or swollen chest is a symptom of mature heartworm infection. It is usually a symptom of a late-stage infection. Fluid retention in the lungs, caused by the parasite infection, can cause the dog’s chest to protrude. The rapid weight loss caused by failure to feed can also cause the ribs to appear bulging.

Late-stage heartworm symptoms usually mean long-term health complications for the dog. The complications include enlarged liver, abnormal sounds in the lungs, and heart murmurs.

It is crucial to treat heartworms before they continue to spread. Identifying the condition is the first step in the treatment process. Treatment for heartworms can be lengthy and costly, and it is usually painful for the dog.

For more heartworm symptoms in a dog, visit Port Royal Veterinary Hospital at our office in Port Royal, South Carolina. You can call 843-379-7387 today to schedule an appointment.