Heartworm Signs for Each Stage of Infection

Heartworm Signs

Are you wondering what signs indicate the presence of heartworms in a dog? Learn about the signs of this dangerous condition, as well as what the symptoms you see might indicate in terms of progression.

Recognizing Heartworm Signs

In order to understand the heartworm signs that your dog might exhibit, you need to be aware of the damage that these parasites can cause. As heartworms grow in the right ventricle of the heart and its blood vessels, blockage begins to occur. As the blood flow from the heart becomes more restricted, inflammation continues to build and fluid continues to accumulate in the lungs. It only takes a matter of days before irreparable damage can occur in the artery lining.

Unfortunately heartworms, which at their adult size can be as much as six inches long or more, can lay thousands of eggs, and this infestation can continue to increase over a long period of time, even over several years. By the time heartworm signs are noticeable, it may be difficult to save the dog's life. As the infestation progresses, a dog may have shortness of breath and coughing spells among other symptoms. The most common heartworm signs include the following:

  • Shortness of breath
  • Coughing
  • Nosebleeds
  • Lethargy
  • Weight loss
  • Low exercise tolerance

It's important to note that the seriousness of the disease depends upon a number of factors including the number of heartworms present, the activity level of the dog and the dog's individual response to the infestation. A dog that is much more active may develop severe heartworm disease with fewer worms present than a dog that is not as active. Unfortunately, a dog's body cannot fight off the infestation as fast as the worms multiply and without treatment, the dog will likely die after a period of time.

Heartworm Symptoms by Stage

The amount of heartworm signs that are detected depends upon when the infestation occurred and how far it has progressed.

  • Early infestation: In the beginning stages of a heartworm infestation, no signs are usually detected.
  • Mild infestation: Typically the earliest heartworm sign is coughing.
  • Moderate infestation: As heartworm disease progresses, other signs in addition to coughing include abnormal lung sounds, lack of energy, loss of weight and loss of appetite.
  • Severe infestation: In addition to the above signs, more severe symptoms include enlarged liver, pneumonia, fluid accumulation in the stomach, loss of consciousness and eventual death.

Seek Medical Attention Immediately

If you suspect your dog has heartworms, contact your veterinarian immediately. He or she may be able to surgically remove the heartworms and save your pet's life.

If your dog is fortunate enough not to have heartworms at this time, take steps to prevent the problem from developing in the future. Talk to your vet about placing your dog on heartworm preventative medication, and have your pet tested regularly for the disease.

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Heartworm Signs for Each Stage of Infection