Canine Dog Heart Worm Symptoms, Signs & Preventative Treatment

Dog Heart Worm Symptoms


dog heart worm symptoms

Dog heart worm symptoms, top advice on the life cycle and how to spot the signs of heartworm in dogs and puppies.

Often these types of worms are the hardest to recognize so follow our step by step guide to recognizing the signs and the best treatment for your dog or puppy.

What is a Heartworm?

  • The heartworm (Dirofilaria Immitis) is a parasite that can be passed from mosquitoes to your dog.
  • After your dog has been bitten by the mosquito, the heartworms will travel through your dog’s blood system until they reach the heart, but more on this later…
  • The parasitic worm is tubular in shape with the male growing up to 23 cm and the female growing slightly longer at 30 cm.

The Heartworm Life Cycle

There are a few stages that the heartworm goes through…

  • Stage 1 – is the baby phase
  • Stage 2 – Stage 3 – This is when the heartworm has reached adulthood and this is when they become a serious danger.


Dog Heart Worm Symptoms

dog heart worm symptoms

What is Happens when your Dog is Infected?

  • Due to their size and shape the parasite is able to block arteries of dogs.
  • The danger is contributed to as your dog would have been infected by more than one heartworm which increase the chance of your dog having one of his arteries blocked.
  • The heart worms will travel through the blood stream until they reach the right chamber of the heart and also the two major blood vessels – the Pulmonary artery and Vena cava.
  • Female heartworms give birth to microfilaria that circulate in the blood and make the blood thicken.

Below we have listed a step by step guide to dog heart worm symptoms…

The signs and symptoms of heartworm can take up to six months to manifest and your vet may need to do some tests but it will take some time for the symptoms to appear.

The parasite also not only causes problems in the heart it also causes problems within the liver blood vessels which can also lead to liver failure.

Take immediate action if your dog shows any of the below signs…

  • A Mild Cough – This is usually the very first symptom that your dog will show and it’s very easy to ignore. 
  • Fatigue/Lethargy/Tiredness – Watch for signs that your dog has lost interest in activities that he used to enjoy, he may spent time lying around, refuse to climb the stairs or get really tired very easily.
  • Trouble with Breathing – Your dog may start gasping for air or seem very short of breath, take him straight to the vet.
  • More Severe Cough – Your dog’s cough will have become more severe and come from deep within his body.
  • Appetite Loss & Weight Loss – Your dog may start refusing food and has lost weight either very suddenly or over a period of time.
  • Jaundice – This is a sign that the liver has been infected, your dog is now very ill and requires immediate surgical intervention from your vet.
  • Collapse & Death – This where it becomes too late to save your beloved dog.


Dog Heart Worm Symptoms – Treatment

Below we have listed some of the treatment that vet’s use to kill the parasite and cure your dog.

  • Adultcide Therapy – Arsenic is administered in safe amounts to your dog either thiacetarsamide sodium or melarsomine dihydrochloride.

After your dog has received this treatment he will need to exercise thoroughly to stop the blood clotting. After this treatment your dog will have a second stage of treatment…

  • Filaricide Therapy – This treatment is to kill the microfilaria, the drugs that are used include milbemycin and ivermectin. It is possible that a third drug is used called levamisole but this also has significant side effects.

Your dog will be blood tested three weeks after the filaricide treatment and if he gets the all clear he will need to start  heartworm preventative program.

Although the side effects and the therapy can be quite severe 95% of dogs that are treated will get the all clear.

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