Taking Care of Your Dog’s Heart

Dog on Log in Woods

The month of February is American Heart Month, a month dedicated to raising awareness to heart health and heart disease prevention. During this time, we mustn’t forget our canine friends and their heart health, specifically with heartworm disease.

Heartworm disease is a serious condition that can cause severe lung disease, heart failure, and other organ damage, and may even result in death. This disease is seen in both dogs and cats.

The destructive disease begins with a simple mosquito bite, where the parasitic worm Dirofilaria immitis enters the bloodstream. The worms mature and reproduce, usually taking hold in the heart and lungs, hence the nickname “heartworm.”

According to the FDA, the factors to consider when having a dog tested for heartworm should include:

  • The dog’s age when heartworm prevention started;
  • If the owner forgot to give heartworm prevention and for how long;
  • If the dog switched from one type of heartworm prevention to another;
  • If the dog recently traveled to an area where heartworm disease is more common; and
  • The length of the heartworm season in the region where the dog lives.

The veterinarian will take a blood sample for an antigen test, which will test for protein markers in the blood that are indicative of heartworms. The very earliest that an antigen test can determine whether a dog is heartworm positive or not is approximately five months after a dog is bitten by an infected mosquito.

Dogs aged seven months and older should be tested prior to starting heartworm prevention. Heartworm preventatives, as the name suggests, do not kill heartworms. Giving a dog heartworm preventative who is infected with heartworms may cause a severe adverse reaction.

If your dog is infected with heartworms, the FDA lists these potential stages of symptoms:

  • Class 1:  No symptoms or mild symptoms such as an occasional cough.
  • Class 2:  Mild to moderate symptoms such as an occasional cough and tiredness after moderate activity.
  • Class 3:  More severe symptoms such as a sickly appearance, a persistent cough, and tiredness after mild activity. Trouble breathing and signs of heart failure are common. For class 2 and 3 heartworm disease, heart and lung changes are usually seen on chest x-rays.
  • Class 4:  Also called caval syndrome. There is such a heavy worm burden that blood flowing back to the heart is physically blocked by a large mass of worms. Caval syndrome is life-threatening and quick surgical removal of the heartworms is the only treatment option. The surgery is risky, and even with surgery, most dogs with caval syndrome die. (FDA)

An Ounce of Prevention is Worth a Pound of Cure

Heartworm treatment is extremely difficult for the pup, as well as costly. Treatment options may include injections, blood tests, numerous visits to the veterinarian, plus, treatment may cause injury to your dog’s body due to toxicity and may have the potential to cause blood clots in their lungs.  

When it comes to heartworm disease, an ounce of prevention is worth a pound of cure. Prevention is the best thing to do to prevent issues with heartworm disease. There are many FDA approved medications (usually monthly doses) that your veterinarian can recommend for your dog.  

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