Most pet owners know they should worm their dogs against gut parasites. Traditionally, a 3-monthly worming tablet covered against the common gut worms that dogs would pick up – tapeworms, hookworms, whipworms and roundworms. However, not all dog owners are familiar with the oddity that is the canine lungworm.

Angiostrongylus vasorum was first discovered in France over 100 years ago. It is a particularly problematic parasite that is ingested by dogs in its larval form, either directly from the environment or via one of its intermediate hosts (snails and slugs).

Once inside the digestive system the larvae embark on a rather circuitous journey, migrating through the wall of the gut into the lymph system. From there they enter the blood stream and pass through the liver and onto the heart and pulmonary arteries.

Here they mature and reproduce, laying eggs that then hatch and release more larvae that are carried through the blood vessels to the lung tissue through which they penetrate before finally being coughed up, swallowed and excreted in the faeces. Then the whole cycle starts again.

The parasite can cause many problems

As you can imagine, a parasite that travels so extensively through the canine body can cause all sorts of problems. Mild symptoms such as a cough may be the only outward sign, but potentially much more serious illnesses can develop such as breathing difficulties, exercise intolerance, lung damage, heart failure and bleeding disorders.

Cases are thought to be on the rise and the incidence of lungworm in native fox populations has shown a significant increase in prevalence over the last 10 years, highlighting the spread of the parasite and increased risk to the dog population.

It is impossible to prevent dogs being exposed while out on walks, but prevention is relatively straightforward. An appropriate monthly worming treatment (that also treats intestinal worms) prevents established infections and the destructive migration of larvae through the lung tissues.

If you are worried about your dog being protected, speak to your vet about what parasite treatments prevent lungworm infections.