Angiostrongylus vasorum, otherwise known as lungworm, is a parasite that lives in the in the lungs and hearts of foxes, coyotes, wolves and dogs. It was first found in France, and is known as the ‘French’ Heartworm.

Recently there have been cases diagnosed in Newfoundland- a wonderful Canadian province by the way… but the ‘experts’ expect it to become established in other areas of Canada, and spread via foxes, coyotes and wolves to the United States.
How does your dog acquire it?
Adult worms live in the arteries of the lung (pulmonary arteries).

A female worm releases eggs into the blood which find their way to the small vessels in the lungs (capillaries)

The eggs become small worms, larvae, which pass into the airways of the lungs.

The larvae are coughed up and swallowed- they then leave your dogs body in the stool (feces).

Slugs and snails ingest the larvae in the stool, they then progress to the next life stage, and are ready to be consumed by more dogs, continuing the cycle.

The consumed larvae are able to go through your dog’s intestinal wall, and migrate to the pulmonary arteries.

Clinical Signs
These are primarily associated with how your dog’s lungs and heart is affected.

Some dogs are asymptomatic ( show few clinical signs), while others can show serious signs:

Persistent cough, breathing difficulty, crackles on listening to the lungs, elevated lung blood pressure leading to a heart murmur, lack of energy, weight loss, vomiting, diarrhea, and in even more serious cases, blood disorders. There can be problems with blood clotting leading to bleeding in different areas ( ie stomach, chest cavity), signs of bleeding in the skin (petechia), and nose bleeding.

Fortunately there are a few safe conventional antiparasitics to treat this disease.

Milbemycin oxime, otherwise known as Milbemax, can be given at a dose of .5mg/kg once daily for 4 weeks.
Fenbendazole ( known as Panacur) can be given at the dose of 20-50mk/kg daily for 5-21 days. (Source, Conboy GA. Canine angiostrongylus: Vet Parasitol 2011;176:382-389)

First don’t be too worried.

It has only been diagnosed in Newfoundland, a province in Canada.

Here are some common questions:

Can humans become infected with the ‘French Heartworm’, Angiostrongylus vasorum?

No- it is species specific

Can cats acquire the ‘French Heartworm’, Angiostrongylus vasorum?


Another type of very uncommon lungworm can affect your cat, this is seldom seen in veterinary practice.

Can dogs infect another dog?


It will not pass directly from dog to dog- it is spread via the intermediate host, a slug or snail.
What can I use to prevent it?

Here is what is being used to prevent and treat it:

1. Milbemycin oxime (Milbemax) at .5mg/kg once a week for 4 weeks

2. Topical moxidectin ( sold as Advocate or Proheart)

3. Imidacloprid moxidectin spot on ( Advantage Multi)

4. Fenbendazole, 20-50mg/kg once daily for 5-21 days

Revolution, which has the active ingredient selamectin, is not being used to prevent or treat this disease.